SAN DIEGO – A newly developed personalized model that “harnesses the power of artificial intelligence” to predict overall survival and transformation to acute myeloid leukemia (AML) in patients with myelodysplastic syndromes outperforms both the original and revised International Prognostic Scoring Systems (IPSS, IPSS-R), according to Aziz Nazha, MD.

The machine learning model, which was built using clinical and genomic data derived from myelodysplastic syndrome (MDS) patients diagnosed according to 2008 World Health Organization criteria, incorporates information beyond that included in the IPSS and IPSS-R, and provides patient-specific survival probabilities at different time points, Dr. Nazha of Cleveland Clinic reported during a press briefing at the annual meeting of the American Society of Hematology.

The model was developed in a combined training cohort of 1,471 patients from the Cleveland Clinic and Munich Leukemia Laboratory and was validated in a separate cohort of 831 patients from the Moffitt Cancer Center in Tampa, Fla.

The concordance index – a measure for comparing the accuracy of the various models – was 0.80 for overall survival (OS), and 0.78 for AML transformation vs. 0.66 and 0.73, respectively, for IPSS, and 0.67 and 0.73, respectively, for IPSS-R, Dr. Nazha said. The new “geno-clinical” model also outperformed mutations-only analysis, mutations plus cytogenetics analysis, and mutations plus cytogenetics plus age analyses for both OS and AML transformation.

Adding mutational variant allelic frequency did not significantly improve prediction accuracy, he noted.

Dr. Nazha and his colleagues are developing a web application tool that can be used to run the trained model to calculate patient-specific, time-specific OS and AML transformation probabilities. He discussed the new model and its implications for personalized prognosis and treatment in this video interview.

Improved risk assessment helps patients understand their disease and “establish expectations about their journey with their disease,” and it is also extremely important for treating physicians, he said.

“All of our consensus guidelines and treatment recommendations are based on risk,” he explained, noting that the approach varies greatly for higher- and lower-risk patients.

This model represents a potential new focus on “personalized prediction” in addition to the increasing focus on personalized treatment and takes into account the heterogeneous outcomes seen in patients with MDS, he said.

Dr. Nazha reported consultancy for Karyopharma and Tolero, and data-monitoring committee membership for MEI.

sworcester@mdedge.com

SOURCE: Nazha A et al. ASH 2018, Abstract 793.

SAN DIEGO – A newly developed personalized model that “harnesses the power of artificial intelligence” to predict overall survival and transformation to acute myeloid leukemia (AML) in patients with myelodysplastic syndromes outperforms both the original and revised International Prognostic Scoring Systems (IPSS, IPSS-R), according to Aziz Nazha, MD.

The machine learning model, which was built using clinical and genomic data derived from myelodysplastic syndrome (MDS) patients diagnosed according to 2008 World Health Organization criteria, incorporates information beyond that included in the IPSS and IPSS-R, and provides patient-specific survival probabilities at different time points, Dr. Nazha of Cleveland Clinic reported during a press briefing at the annual meeting of the American Society of Hematology.

The model was developed in a combined training cohort of 1,471 patients from the Cleveland Clinic and Munich Leukemia Laboratory and was validated in a separate cohort of 831 patients from the Moffitt Cancer Center in Tampa, Fla.

The concordance index – a measure for comparing the accuracy of the various models – was 0.80 for overall survival (OS), and 0.78 for AML transformation vs. 0.66 and 0.73, respectively, for IPSS, and 0.67 and 0.73, respectively, for IPSS-R, Dr. Nazha said. The new “geno-clinical” model also outperformed mutations-only analysis, mutations plus cytogenetics analysis, and mutations plus cytogenetics plus age analyses for both OS and AML transformation.

Adding mutational variant allelic frequency did not significantly improve prediction accuracy, he noted.

Dr. Nazha and his colleagues are developing a web application tool that can be used to run the trained model to calculate patient-specific, time-specific OS and AML transformation probabilities. He discussed the new model and its implications for personalized prognosis and treatment in this video interview.

Improved risk assessment helps patients understand their disease and “establish expectations about their journey with their disease,” and it is also extremely important for treating physicians, he said.

“All of our consensus guidelines and treatment recommendations are based on risk,” he explained, noting that the approach varies greatly for higher- and lower-risk patients.

This model represents a potential new focus on “personalized prediction” in addition to the increasing focus on personalized treatment and takes into account the heterogeneous outcomes seen in patients with MDS, he said.

Dr. Nazha reported consultancy for Karyopharma and Tolero, and data-monitoring committee membership for MEI.

sworcester@mdedge.com

SOURCE: Nazha A et al. ASH 2018, Abstract 793.

SAN DIEGO – A newly developed personalized model that “harnesses the power of artificial intelligence” to predict overall survival and transformation to acute myeloid leukemia (AML) in patients with myelodysplastic syndromes outperforms both the original and revised International Prognostic Scoring Systems (IPSS, IPSS-R), according to Aziz Nazha, MD.

The machine learning model, which was built using clinical and genomic data derived from myelodysplastic syndrome (MDS) patients diagnosed according to 2008 World Health Organization criteria, incorporates information beyond that included in the IPSS and IPSS-R, and provides patient-specific survival probabilities at different time points, Dr. Nazha of Cleveland Clinic reported during a press briefing at the annual meeting of the American Society of Hematology.

The model was developed in a combined training cohort of 1,471 patients from the Cleveland Clinic and Munich Leukemia Laboratory and was validated in a separate cohort of 831 patients from the Moffitt Cancer Center in Tampa, Fla.

The concordance index – a measure for comparing the accuracy of the various models – was 0.80 for overall survival (OS), and 0.78 for AML transformation vs. 0.66 and 0.73, respectively, for IPSS, and 0.67 and 0.73, respectively, for IPSS-R, Dr. Nazha said. The new “geno-clinical” model also outperformed mutations-only analysis, mutations plus cytogenetics analysis, and mutations plus cytogenetics plus age analyses for both OS and AML transformation.

Adding mutational variant allelic frequency did not significantly improve prediction accuracy, he noted.

Dr. Nazha and his colleagues are developing a web application tool that can be used to run the trained model to calculate patient-specific, time-specific OS and AML transformation probabilities. He discussed the new model and its implications for personalized prognosis and treatment in this video interview.

Improved risk assessment helps patients understand their disease and “establish expectations about their journey with their disease,” and it is also extremely important for treating physicians, he said.

“All of our consensus guidelines and treatment recommendations are based on risk,” he explained, noting that the approach varies greatly for higher- and lower-risk patients.

This model represents a potential new focus on “personalized prediction” in addition to the increasing focus on personalized treatment and takes into account the heterogeneous outcomes seen in patients with MDS, he said.

Dr. Nazha reported consultancy for Karyopharma and Tolero, and data-monitoring committee membership for MEI.

sworcester@mdedge.com

SOURCE: Nazha A et al. ASH 2018, Abstract 793.

Comorbidity between headaches with a range of physical conditions that have been associated with adult migraine demonstrates that multimorbidity occurs early in development. This according to a recent study that examined the associations between headaches and migraine with physical and mental disorders in a large pediatric registry. The study included 9,329 youth aged 8-21 years from the Philadelphia Neurodevelopmental Cohort. Physical conditions, including headache, were ascertained from electronic medical records and in-person interviews. Modified International Classification of Headache Disorders (ICHD-II) criteria were used to classify migraine symptoms. Forty-two other physical conditions were classified into 14 classes of medical disorders. Researchers found:

• Lifetime prevalence of any headache was 45.5%, and of migraine was 22.6%.
• Any headache was associated with a broad range of physical disorders, attention-deficit/hyperactivity disorder (odds ratio [OR] 1.2), and behavior disorders (1.3).
• Youth with migraine had greater odds of specific physical conditions and mental disorders, including respiratory, neurologic/central nervous system, developmental, anxiety, behavior, and mood disorders than those with non-migraine headache (OR ranged from 1.3 to 1.9).

Lateef T, He J-P, Nelson K, et al. Physical–mental comorbidity of pediatric migraine in the Philadelphia Neurodevelopmental Cohort. [Published online ahead of print October 29, 2018]. J Pediatr. doi:10.1016/j.jpeds.2018.09.033.

Comorbidity between headaches with a range of physical conditions that have been associated with adult migraine demonstrates that multimorbidity occurs early in development. This according to a recent study that examined the associations between headaches and migraine with physical and mental disorders in a large pediatric registry. The study included 9,329 youth aged 8-21 years from the Philadelphia Neurodevelopmental Cohort. Physical conditions, including headache, were ascertained from electronic medical records and in-person interviews. Modified International Classification of Headache Disorders (ICHD-II) criteria were used to classify migraine symptoms. Forty-two other physical conditions were classified into 14 classes of medical disorders. Researchers found:

• Lifetime prevalence of any headache was 45.5%, and of migraine was 22.6%.
• Any headache was associated with a broad range of physical disorders, attention-deficit/hyperactivity disorder (odds ratio [OR] 1.2), and behavior disorders (1.3).
• Youth with migraine had greater odds of specific physical conditions and mental disorders, including respiratory, neurologic/central nervous system, developmental, anxiety, behavior, and mood disorders than those with non-migraine headache (OR ranged from 1.3 to 1.9).

Lateef T, He J-P, Nelson K, et al. Physical–mental comorbidity of pediatric migraine in the Philadelphia Neurodevelopmental Cohort. [Published online ahead of print October 29, 2018]. J Pediatr. doi:10.1016/j.jpeds.2018.09.033.

Comorbidity between headaches with a range of physical conditions that have been associated with adult migraine demonstrates that multimorbidity occurs early in development. This according to a recent study that examined the associations between headaches and migraine with physical and mental disorders in a large pediatric registry. The study included 9,329 youth aged 8-21 years from the Philadelphia Neurodevelopmental Cohort. Physical conditions, including headache, were ascertained from electronic medical records and in-person interviews. Modified International Classification of Headache Disorders (ICHD-II) criteria were used to classify migraine symptoms. Forty-two other physical conditions were classified into 14 classes of medical disorders. Researchers found:

• Lifetime prevalence of any headache was 45.5%, and of migraine was 22.6%.
• Any headache was associated with a broad range of physical disorders, attention-deficit/hyperactivity disorder (odds ratio [OR] 1.2), and behavior disorders (1.3).
• Youth with migraine had greater odds of specific physical conditions and mental disorders, including respiratory, neurologic/central nervous system, developmental, anxiety, behavior, and mood disorders than those with non-migraine headache (OR ranged from 1.3 to 1.9).

Lateef T, He J-P, Nelson K, et al. Physical–mental comorbidity of pediatric migraine in the Philadelphia Neurodevelopmental Cohort. [Published online ahead of print October 29, 2018]. J Pediatr. doi:10.1016/j.jpeds.2018.09.033.

Recent findings suggest an abnormal sensory integration for spatial orientation in vestibular migraine (VM), related to daily dizziness in these patients. Researchers investigated the effect of static head tilts on errors of upright perception in a group of 27 patients with VM in comparison with a group of 27 healthy controls. Perception of upright was measured in a dark room using a subjective visual vertical (SVV) paradigm at 3 head tilt positions (upright, ±20°). VM patients were also surveyed about the quality of their dizziness and spatial symptoms during daily activities. Researchers found:

• In the upright head position, SVV errors were within the normal range for VM patients and healthy controls (within 2° from true vertical).
• During the static head tilts of 20° to the right, VM patients showed larger SVV errors consistent with overestimation of the tilt magnitude (ie, as if they felt further tilted toward the right side) (VM: −3.21° ± 0.93 vs control: 0.52° ± 0.70).
• During the head tilt to the left, SVV errors in VM patients did not differ significantly from controls (VM: 0.77° ± 1.05 vs control: −0.04° ± 0.68).

Winnick A, Sadeghpour S, Otero-Millan J, Chang T-P, Kheradmand A. Errors of upright perception in patients with vestibular migraine. [Published online ahead of print October 30, 2018]. Front Neurol. doi:10.3389/fneur.2018.00892.

Recent findings suggest an abnormal sensory integration for spatial orientation in vestibular migraine (VM), related to daily dizziness in these patients. Researchers investigated the effect of static head tilts on errors of upright perception in a group of 27 patients with VM in comparison with a group of 27 healthy controls. Perception of upright was measured in a dark room using a subjective visual vertical (SVV) paradigm at 3 head tilt positions (upright, ±20°). VM patients were also surveyed about the quality of their dizziness and spatial symptoms during daily activities. Researchers found:

• In the upright head position, SVV errors were within the normal range for VM patients and healthy controls (within 2° from true vertical).
• During the static head tilts of 20° to the right, VM patients showed larger SVV errors consistent with overestimation of the tilt magnitude (ie, as if they felt further tilted toward the right side) (VM: −3.21° ± 0.93 vs control: 0.52° ± 0.70).
• During the head tilt to the left, SVV errors in VM patients did not differ significantly from controls (VM: 0.77° ± 1.05 vs control: −0.04° ± 0.68).

Winnick A, Sadeghpour S, Otero-Millan J, Chang T-P, Kheradmand A. Errors of upright perception in patients with vestibular migraine. [Published online ahead of print October 30, 2018]. Front Neurol. doi:10.3389/fneur.2018.00892.

Recent findings suggest an abnormal sensory integration for spatial orientation in vestibular migraine (VM), related to daily dizziness in these patients. Researchers investigated the effect of static head tilts on errors of upright perception in a group of 27 patients with VM in comparison with a group of 27 healthy controls. Perception of upright was measured in a dark room using a subjective visual vertical (SVV) paradigm at 3 head tilt positions (upright, ±20°). VM patients were also surveyed about the quality of their dizziness and spatial symptoms during daily activities. Researchers found:

• In the upright head position, SVV errors were within the normal range for VM patients and healthy controls (within 2° from true vertical).
• During the static head tilts of 20° to the right, VM patients showed larger SVV errors consistent with overestimation of the tilt magnitude (ie, as if they felt further tilted toward the right side) (VM: −3.21° ± 0.93 vs control: 0.52° ± 0.70).
• During the head tilt to the left, SVV errors in VM patients did not differ significantly from controls (VM: 0.77° ± 1.05 vs control: −0.04° ± 0.68).

Winnick A, Sadeghpour S, Otero-Millan J, Chang T-P, Kheradmand A. Errors of upright perception in patients with vestibular migraine. [Published online ahead of print October 30, 2018]. Front Neurol. doi:10.3389/fneur.2018.00892.

Migraine with aura was associated with increased risk of incident atrial fibrillation (AF), according to a recent study, and this may potentially lead to ischemic strokes. In the Atherosclerosis Risk in Communities (ARIC) study, a longitudinal, community-based cohort study, participants were interviewed for migraine history between 1993 and 1995 and were followed for incident AF through 2013. AF was adjudicated using electrocardiographs (ECGs), discharge codes, and death certificates. Researchers found:

• Of 11,939 participants assessed for headache and without prior AF or stroke, 426 reported migraines with visual aura, 1090 with migraine without visual aura, 1018 non-migraine headache, and 9405 no headache.
• Over a 20-year follow-up period, incident AF was noted in 232 (15%) of 1516 with migraine and 1623 (17%) of 9405 without headache.
• After adjustment for multiple confounders, migraine with visual aura was associated with increased risk of AF compared to no headache (hazard ratio 1.30) as well as when compared to migraine without visual aura (hazard ratio 1.39).
• The data suggest that AF may be a potential mediator of migraine with visual aura–stroke risk.

Sen S, Androulakis XM, Duda V, et al. Migraine with visual aura a risk factor for incident atrial fibrillation. A cohort study. [Published online ahead of print November 14, 2018]. Neurology. doi:10.1212/WNL.0000000000006650.

Migraine with aura was associated with increased risk of incident atrial fibrillation (AF), according to a recent study, and this may potentially lead to ischemic strokes. In the Atherosclerosis Risk in Communities (ARIC) study, a longitudinal, community-based cohort study, participants were interviewed for migraine history between 1993 and 1995 and were followed for incident AF through 2013. AF was adjudicated using electrocardiographs (ECGs), discharge codes, and death certificates. Researchers found:

• Of 11,939 participants assessed for headache and without prior AF or stroke, 426 reported migraines with visual aura, 1090 with migraine without visual aura, 1018 non-migraine headache, and 9405 no headache.
• Over a 20-year follow-up period, incident AF was noted in 232 (15%) of 1516 with migraine and 1623 (17%) of 9405 without headache.
• After adjustment for multiple confounders, migraine with visual aura was associated with increased risk of AF compared to no headache (hazard ratio 1.30) as well as when compared to migraine without visual aura (hazard ratio 1.39).
• The data suggest that AF may be a potential mediator of migraine with visual aura–stroke risk.

Sen S, Androulakis XM, Duda V, et al. Migraine with visual aura a risk factor for incident atrial fibrillation. A cohort study. [Published online ahead of print November 14, 2018]. Neurology. doi:10.1212/WNL.0000000000006650.

Migraine with aura was associated with increased risk of incident atrial fibrillation (AF), according to a recent study, and this may potentially lead to ischemic strokes. In the Atherosclerosis Risk in Communities (ARIC) study, a longitudinal, community-based cohort study, participants were interviewed for migraine history between 1993 and 1995 and were followed for incident AF through 2013. AF was adjudicated using electrocardiographs (ECGs), discharge codes, and death certificates. Researchers found:

• Of 11,939 participants assessed for headache and without prior AF or stroke, 426 reported migraines with visual aura, 1090 with migraine without visual aura, 1018 non-migraine headache, and 9405 no headache.
• Over a 20-year follow-up period, incident AF was noted in 232 (15%) of 1516 with migraine and 1623 (17%) of 9405 without headache.
• After adjustment for multiple confounders, migraine with visual aura was associated with increased risk of AF compared to no headache (hazard ratio 1.30) as well as when compared to migraine without visual aura (hazard ratio 1.39).
• The data suggest that AF may be a potential mediator of migraine with visual aura–stroke risk.

Sen S, Androulakis XM, Duda V, et al. Migraine with visual aura a risk factor for incident atrial fibrillation. A cohort study. [Published online ahead of print November 14, 2018]. Neurology. doi:10.1212/WNL.0000000000006650.

NEW ORLEANS – Seizure frequency increased during pregnancy for 53% of women with frontal lobe epilepsy, based on a study reported by Paula E. Voinescu, MD, PhD, at the annual meeting of the American Epilepsy Society.

Jacob Remaly/MDedge News

The single center study included data on 76 pregnancies in women with focal epilepsy –17 of them in patients with frontal lobe epilepsy – and 38 pregnancies in women with generalized epilepsy. Seizures were more frequent during pregnancy, compared with baseline, in 5.5% of women with generalized epilepsy, 22.6% of women with focal epilepsies, and 53.0% of women with frontal lobe epilepsy, said Dr. Voinescu, lead author of the study and a neurologist at Brigham and Women’s Hospital in Boston.

“Frontal lobe epilepsy is known to be difficult to manage in general and often resistant to therapy, but it isn’t clear why the seizures got worse among pregnant women because the levels of medication in their blood was considered adequate. Until more research provides treatment guidance, doctors should carefully monitor their pregnant patients who have focal epilepsy to see if their seizures increase despite adequate blood levels and then adjust their medication if necessary,” she advised. “As we know from other research, seizures during pregnancy can increase the risk of distress and neurodevelopmental delays for the baby, as well as the risk of miscarriage.”

For the study, Dr. Voinescu and her colleagues analyzed prospectively collected clinical data from 99 pregnant women followed at Brigham and Women’s Hospital between 2013 and 2018.

The researchers excluded patients with abortions, seizure onset during pregnancy, poorly defined preconception seizure frequency, nonepileptic seizures, antiepileptic drug (AED) noncompliance, and pregnancies that were enrolled in other studies. The investigators documented patients’ seizure types and AED regimens and recorded seizure frequency during the 9 months before conception, during pregnancy, and 9 months postpartum. The researchers summed all seizures for each individual for each interval. They defined seizure frequency worsening as any increase above the preconception baseline, and evaluated differences between focal and generalized epilepsy and between frontal lobe and other focal epilepsies.

Increased seizure activity tended to occur in women on more than one AED, according to Dr. Voinescu. In women with frontal lobe epilepsy, seizure worsening during pregnancy was most likely to begin in the second trimester.

The gap in seizure frequency between the groups narrowed in the 9-month postpartum period. Seizures were more frequent during the postpartum period, compared with baseline, in 12.12% of women with generalized epilepsy, 20.14% of women with focal epilepsies, and 20.00% of women with frontal lobe epilepsy.

Future analyses will evaluate the influence of AED type and concentration and specific timing on seizure control during pregnancy and the postpartum period, Dr. Voinescu said. Future studies should also include measures of sleep, which may be a contributory mechanism to the differences found between these epilepsy types.

Dr. Voinescu reported receiving funding from the American Brain Foundation, the American Epilepsy Society, and the Epilepsy Foundation through the Susan Spencer Clinical Research Fellowship.

jremaly@mdedge.com

SOURCE: Voinescu PE et al. AES 2018, Abstract 3.236.

NEW ORLEANS – Seizure frequency increased during pregnancy for 53% of women with frontal lobe epilepsy, based on a study reported by Paula E. Voinescu, MD, PhD, at the annual meeting of the American Epilepsy Society.

Jacob Remaly/MDedge News

The single center study included data on 76 pregnancies in women with focal epilepsy –17 of them in patients with frontal lobe epilepsy – and 38 pregnancies in women with generalized epilepsy. Seizures were more frequent during pregnancy, compared with baseline, in 5.5% of women with generalized epilepsy, 22.6% of women with focal epilepsies, and 53.0% of women with frontal lobe epilepsy, said Dr. Voinescu, lead author of the study and a neurologist at Brigham and Women’s Hospital in Boston.

“Frontal lobe epilepsy is known to be difficult to manage in general and often resistant to therapy, but it isn’t clear why the seizures got worse among pregnant women because the levels of medication in their blood was considered adequate. Until more research provides treatment guidance, doctors should carefully monitor their pregnant patients who have focal epilepsy to see if their seizures increase despite adequate blood levels and then adjust their medication if necessary,” she advised. “As we know from other research, seizures during pregnancy can increase the risk of distress and neurodevelopmental delays for the baby, as well as the risk of miscarriage.”

For the study, Dr. Voinescu and her colleagues analyzed prospectively collected clinical data from 99 pregnant women followed at Brigham and Women’s Hospital between 2013 and 2018.

The researchers excluded patients with abortions, seizure onset during pregnancy, poorly defined preconception seizure frequency, nonepileptic seizures, antiepileptic drug (AED) noncompliance, and pregnancies that were enrolled in other studies. The investigators documented patients’ seizure types and AED regimens and recorded seizure frequency during the 9 months before conception, during pregnancy, and 9 months postpartum. The researchers summed all seizures for each individual for each interval. They defined seizure frequency worsening as any increase above the preconception baseline, and evaluated differences between focal and generalized epilepsy and between frontal lobe and other focal epilepsies.

Increased seizure activity tended to occur in women on more than one AED, according to Dr. Voinescu. In women with frontal lobe epilepsy, seizure worsening during pregnancy was most likely to begin in the second trimester.

The gap in seizure frequency between the groups narrowed in the 9-month postpartum period. Seizures were more frequent during the postpartum period, compared with baseline, in 12.12% of women with generalized epilepsy, 20.14% of women with focal epilepsies, and 20.00% of women with frontal lobe epilepsy.

Future analyses will evaluate the influence of AED type and concentration and specific timing on seizure control during pregnancy and the postpartum period, Dr. Voinescu said. Future studies should also include measures of sleep, which may be a contributory mechanism to the differences found between these epilepsy types.

Dr. Voinescu reported receiving funding from the American Brain Foundation, the American Epilepsy Society, and the Epilepsy Foundation through the Susan Spencer Clinical Research Fellowship.

jremaly@mdedge.com

SOURCE: Voinescu PE et al. AES 2018, Abstract 3.236.

NEW ORLEANS – Seizure frequency increased during pregnancy for 53% of women with frontal lobe epilepsy, based on a study reported by Paula E. Voinescu, MD, PhD, at the annual meeting of the American Epilepsy Society.

Jacob Remaly/MDedge News

The single center study included data on 76 pregnancies in women with focal epilepsy –17 of them in patients with frontal lobe epilepsy – and 38 pregnancies in women with generalized epilepsy. Seizures were more frequent during pregnancy, compared with baseline, in 5.5% of women with generalized epilepsy, 22.6% of women with focal epilepsies, and 53.0% of women with frontal lobe epilepsy, said Dr. Voinescu, lead author of the study and a neurologist at Brigham and Women’s Hospital in Boston.

“Frontal lobe epilepsy is known to be difficult to manage in general and often resistant to therapy, but it isn’t clear why the seizures got worse among pregnant women because the levels of medication in their blood was considered adequate. Until more research provides treatment guidance, doctors should carefully monitor their pregnant patients who have focal epilepsy to see if their seizures increase despite adequate blood levels and then adjust their medication if necessary,” she advised. “As we know from other research, seizures during pregnancy can increase the risk of distress and neurodevelopmental delays for the baby, as well as the risk of miscarriage.”

For the study, Dr. Voinescu and her colleagues analyzed prospectively collected clinical data from 99 pregnant women followed at Brigham and Women’s Hospital between 2013 and 2018.

The researchers excluded patients with abortions, seizure onset during pregnancy, poorly defined preconception seizure frequency, nonepileptic seizures, antiepileptic drug (AED) noncompliance, and pregnancies that were enrolled in other studies. The investigators documented patients’ seizure types and AED regimens and recorded seizure frequency during the 9 months before conception, during pregnancy, and 9 months postpartum. The researchers summed all seizures for each individual for each interval. They defined seizure frequency worsening as any increase above the preconception baseline, and evaluated differences between focal and generalized epilepsy and between frontal lobe and other focal epilepsies.

Increased seizure activity tended to occur in women on more than one AED, according to Dr. Voinescu. In women with frontal lobe epilepsy, seizure worsening during pregnancy was most likely to begin in the second trimester.

The gap in seizure frequency between the groups narrowed in the 9-month postpartum period. Seizures were more frequent during the postpartum period, compared with baseline, in 12.12% of women with generalized epilepsy, 20.14% of women with focal epilepsies, and 20.00% of women with frontal lobe epilepsy.

Future analyses will evaluate the influence of AED type and concentration and specific timing on seizure control during pregnancy and the postpartum period, Dr. Voinescu said. Future studies should also include measures of sleep, which may be a contributory mechanism to the differences found between these epilepsy types.

Dr. Voinescu reported receiving funding from the American Brain Foundation, the American Epilepsy Society, and the Epilepsy Foundation through the Susan Spencer Clinical Research Fellowship.

jremaly@mdedge.com

SOURCE: Voinescu PE et al. AES 2018, Abstract 3.236.

Recent years have seen dramatic increases in the prevalences of chronic diseases such as type 1 diabetes,¹ gastroesophageal reflux disease,² asthma,³ inflammatory bowel disease,⁴ and, notably, obesity.⁵ I propose the hypothesis that much of this increase may be due to loss of diversity in the bacteria that make our guts their home.⁶ While multiple causes contribute, much of the blame may be attributed to the use—and overuse—of antibiotics.

FAT AND GETTING FATTER

Today, nearly 40% of US adults are obese, and nearly three-fourths are either obese or overweight.⁷ More alarming, the prevalence of obesity is also high and getting higher in children and adolescents,⁸ having increased from 10.0% in 1988–1994 to 17.8% in 2013–2016.

And not just in the United States. Trends in weight have been going up around the world, with a lag of about 30 years between developing countries and industrialized countries.5

OUR BACTERIA, OURSELVES

I believe that the bacteria we carry are not random, but rather have coevolved along with us, passed down from generation to generation in a state of dynamic equilibrium between microbes and host. Evidence supporting this comes from a study by Ochman et al,⁹ who analyzed the DNA from fecal samples from different hominid species (including Homo sapiens) and found that the phylogenic relationships among the bacteria mirrored those among the apes.

Interacting with each other and with us in complex ways, our bacteria are a diverse community to which we can apply the term microbiome. They are acquired in a standard, choreographed process,¹⁰ and their composition comes to resemble that of adults by the age of 3.¹¹

Before modern times, microbes were transferred from mother to child during vaginal birth, from the mother’s breast during nursing, through skin-to-skin contact, and from the mother’s mouth by kissing. Now, widespread cesarean delivery, bottle-feeding, extensive bathing (especially with antibacterial soaps), and especially the use of antibiotics have changed the human ecology and altered transmission and maintenance of ancestral microbes, which affects the composition of the microbiota. The microbes, both good and bad, that are usually acquired early in life are especially important, since they affect a developmentally critical stage.¹²

Loss of microbial diversity in the mother appears to be cumulative over succeeding generations.¹³ For example, in a study in Japanese families, Urita et al¹⁴ found a decline in the prevalence of Helicobacter pylori colonization from 68.7% in the first generation to 43.4% in the second generation and 12.5% in the third. Clemente et al¹⁵ studied the intestinal microbiota in a previously uncontacted group of Yanomami people in the Amazon jungle and found they had the highest diversity of bacteria ever reported in a human group. By comparison, the research team calculated that we in the United States have already lost 50% of our microbial diversity, and 2 other groups, the Guahibo (another Amerindian group) and rural Malawians, were in between. More recent studies are confirming these observations.^16,17

 

 

USE AND OVERUSE OF ANTIBIOTICS

More than 73 billion antibiotic doses are prescribed worldwide yearly,¹⁸ or about 10 doses for every man, woman, and child on Earth, and the numbers are rising. In the United States 262 million courses were prescribed in 2011, or 842 per 1,000 population.¹⁹ Children receive a mean of 2.7 courses by age 2, and 10.9 by age 10. More than 50% of women receive antibiotics during pregnancy or perinatally. This is in addition to an unknown level of exposure from agricultural use of antibiotics.

Repeated antibiotic exposure is common in early life, varies widely by country, and is often not medically justified.²⁰ In the United States, antibiotic use varies by region, with the heaviest use in the South.^19,21 It also varies widely among prescribers.²² Jones et al²³ examined antibiotic prescribing for acute respiratory infections in US veterans and found that the top 10% of physicians gave an antibiotic more than 90% of the time. Physicians in Sweden prescribe about 60% fewer antibiotics than we do in the United States.^21,24

Observational data indicate that people who receive antibiotics have a higher risk of chronic diseases later in life, eg:

• Type 2 diabetes (odds ratio 1.21, 95% confidence interval 1.19–1.23 with 2 to 4 courses, and odds ratio 1.53 (1.50–1.55) with 5 or more courses, up to 15 years after²⁵
• Obesity: US states with the highest prevalence of antibiotic use also have the highest prevalence of obesity²⁶
• Kidney stones: prior antibiotic exposure in a large UK study was associated with increased kidney stone risk, for exposures up to 5 years earlier.²⁷

The meat industry has exploited the weight effect for decades, adding subtherapeutic doses of antibiotics to animals’ feed to make them gain weight.²8

FINDINGS FROM STUDIES IN MICE

Laboratory studies of the relationship between antibiotic exposure and disease phenotypes in mice have yielded interesting findings.

Mice exposed to antibiotics had more body fat at 10 weeks (32.0%) than control mice (22.9%).²⁹

Low-dose penicillin, started at birth, induces long-lasting effects on the expression of genes involved in immunity and enhances the effect of a high-fat diet in terms of weight gain.³⁰ If the antibiotic exposure is limited to early life, the effect on the microbiota is transient, but the mice still gain weight. If the microbiota from the mice who received penicillin is transferred to germ-free mice, the recipients also become fat, indicating that the bacteria, not the antibiotics per se, cause the weight gain.

In other experiments,³¹ a series of short, therapeutic doses of antibiotics early in life modeled after those given to children to treat their acute infections caused long-term changes in the composition of the microbiome and in metabolism.

A single course of a macrolide antibiotic also had long-term effects on the microbial population and on the host’s ileal gene expression, T-cell populations, and secretory immunoglobulin A expression.³² These effects were seen only in mice that had a microbiome to begin with, not in germ-free mice, indicating that the antibiotics had their effect through the changes in the microbiome, not directly. But when germ-free mice received a fecal transplant of an impaired microbiome, it was sufficient to affect immunity.

In nonobese diabetic mice, treatment with antibiotics early in life altered the gut microbiome and its metabolic capacities, intestinal gene expression, and T-cell populations, accelerating the onset of type 1 diabetes.³³

In a study in Danish children,³⁴ the likelihood of inflammatory bowel disease increased with early-life antibiotic exposure: the more courses the child received, the greater the likelihood of disease. This observation led researchers to wonder if an antibiotic-altered microbiome affects the outcome of inflammatory bowel disease in the next generation.³⁵ Germ-free female mice who received microbiota from mice who had received antibiotics passed the altered microbiome to their pups. Mice lacking the gene for interleukin 10 are genetically susceptible to colitis, and when this experiment was done in mice lacking this gene, the offspring developed markedly more colitis. This indicated the mothers could pass down their altered microbiome to the next generation and that it would affect their risk of disease.

WHAT CAN WE DO?

All physicians must adhere to the principles of antibiotic stewardship,³⁶ not only to prevent the development of resistant strains of pathogens and the overgrowth of potentially dangerous species such as Clostridium difficile, but also, possibly, to prevent the loss of diversity in the human microbiome and thus discourage the development of chronic diseases.

In the future, as we discover more about the microbiome and the optimal mix of bacteria to carry, this information may find practical application in medicine. A pediatrician, for example, may want to analyze a child’s microbiome and, if it is abnormal, administer specific organisms to reshape it.

Recent years have seen dramatic increases in the prevalences of chronic diseases such as type 1 diabetes,¹ gastroesophageal reflux disease,² asthma,³ inflammatory bowel disease,⁴ and, notably, obesity.⁵ I propose the hypothesis that much of this increase may be due to loss of diversity in the bacteria that make our guts their home.⁶ While multiple causes contribute, much of the blame may be attributed to the use—and overuse—of antibiotics.

FAT AND GETTING FATTER

Today, nearly 40% of US adults are obese, and nearly three-fourths are either obese or overweight.⁷ More alarming, the prevalence of obesity is also high and getting higher in children and adolescents,⁸ having increased from 10.0% in 1988–1994 to 17.8% in 2013–2016.

And not just in the United States. Trends in weight have been going up around the world, with a lag of about 30 years between developing countries and industrialized countries.5

OUR BACTERIA, OURSELVES

I believe that the bacteria we carry are not random, but rather have coevolved along with us, passed down from generation to generation in a state of dynamic equilibrium between microbes and host. Evidence supporting this comes from a study by Ochman et al,⁹ who analyzed the DNA from fecal samples from different hominid species (including Homo sapiens) and found that the phylogenic relationships among the bacteria mirrored those among the apes.

Interacting with each other and with us in complex ways, our bacteria are a diverse community to which we can apply the term microbiome. They are acquired in a standard, choreographed process,¹⁰ and their composition comes to resemble that of adults by the age of 3.¹¹

Before modern times, microbes were transferred from mother to child during vaginal birth, from the mother’s breast during nursing, through skin-to-skin contact, and from the mother’s mouth by kissing. Now, widespread cesarean delivery, bottle-feeding, extensive bathing (especially with antibacterial soaps), and especially the use of antibiotics have changed the human ecology and altered transmission and maintenance of ancestral microbes, which affects the composition of the microbiota. The microbes, both good and bad, that are usually acquired early in life are especially important, since they affect a developmentally critical stage.¹²

Loss of microbial diversity in the mother appears to be cumulative over succeeding generations.¹³ For example, in a study in Japanese families, Urita et al¹⁴ found a decline in the prevalence of Helicobacter pylori colonization from 68.7% in the first generation to 43.4% in the second generation and 12.5% in the third. Clemente et al¹⁵ studied the intestinal microbiota in a previously uncontacted group of Yanomami people in the Amazon jungle and found they had the highest diversity of bacteria ever reported in a human group. By comparison, the research team calculated that we in the United States have already lost 50% of our microbial diversity, and 2 other groups, the Guahibo (another Amerindian group) and rural Malawians, were in between. More recent studies are confirming these observations.^16,17

 

 

USE AND OVERUSE OF ANTIBIOTICS

More than 73 billion antibiotic doses are prescribed worldwide yearly,¹⁸ or about 10 doses for every man, woman, and child on Earth, and the numbers are rising. In the United States 262 million courses were prescribed in 2011, or 842 per 1,000 population.¹⁹ Children receive a mean of 2.7 courses by age 2, and 10.9 by age 10. More than 50% of women receive antibiotics during pregnancy or perinatally. This is in addition to an unknown level of exposure from agricultural use of antibiotics.

Repeated antibiotic exposure is common in early life, varies widely by country, and is often not medically justified.²⁰ In the United States, antibiotic use varies by region, with the heaviest use in the South.^19,21 It also varies widely among prescribers.²² Jones et al²³ examined antibiotic prescribing for acute respiratory infections in US veterans and found that the top 10% of physicians gave an antibiotic more than 90% of the time. Physicians in Sweden prescribe about 60% fewer antibiotics than we do in the United States.^21,24

Observational data indicate that people who receive antibiotics have a higher risk of chronic diseases later in life, eg:

• Type 2 diabetes (odds ratio 1.21, 95% confidence interval 1.19–1.23 with 2 to 4 courses, and odds ratio 1.53 (1.50–1.55) with 5 or more courses, up to 15 years after²⁵
• Obesity: US states with the highest prevalence of antibiotic use also have the highest prevalence of obesity²⁶
• Kidney stones: prior antibiotic exposure in a large UK study was associated with increased kidney stone risk, for exposures up to 5 years earlier.²⁷

The meat industry has exploited the weight effect for decades, adding subtherapeutic doses of antibiotics to animals’ feed to make them gain weight.²8

FINDINGS FROM STUDIES IN MICE

Laboratory studies of the relationship between antibiotic exposure and disease phenotypes in mice have yielded interesting findings.

Mice exposed to antibiotics had more body fat at 10 weeks (32.0%) than control mice (22.9%).²⁹

Low-dose penicillin, started at birth, induces long-lasting effects on the expression of genes involved in immunity and enhances the effect of a high-fat diet in terms of weight gain.³⁰ If the antibiotic exposure is limited to early life, the effect on the microbiota is transient, but the mice still gain weight. If the microbiota from the mice who received penicillin is transferred to germ-free mice, the recipients also become fat, indicating that the bacteria, not the antibiotics per se, cause the weight gain.

In other experiments,³¹ a series of short, therapeutic doses of antibiotics early in life modeled after those given to children to treat their acute infections caused long-term changes in the composition of the microbiome and in metabolism.

A single course of a macrolide antibiotic also had long-term effects on the microbial population and on the host’s ileal gene expression, T-cell populations, and secretory immunoglobulin A expression.³² These effects were seen only in mice that had a microbiome to begin with, not in germ-free mice, indicating that the antibiotics had their effect through the changes in the microbiome, not directly. But when germ-free mice received a fecal transplant of an impaired microbiome, it was sufficient to affect immunity.

In nonobese diabetic mice, treatment with antibiotics early in life altered the gut microbiome and its metabolic capacities, intestinal gene expression, and T-cell populations, accelerating the onset of type 1 diabetes.³³

In a study in Danish children,³⁴ the likelihood of inflammatory bowel disease increased with early-life antibiotic exposure: the more courses the child received, the greater the likelihood of disease. This observation led researchers to wonder if an antibiotic-altered microbiome affects the outcome of inflammatory bowel disease in the next generation.³⁵ Germ-free female mice who received microbiota from mice who had received antibiotics passed the altered microbiome to their pups. Mice lacking the gene for interleukin 10 are genetically susceptible to colitis, and when this experiment was done in mice lacking this gene, the offspring developed markedly more colitis. This indicated the mothers could pass down their altered microbiome to the next generation and that it would affect their risk of disease.

WHAT CAN WE DO?

All physicians must adhere to the principles of antibiotic stewardship,³⁶ not only to prevent the development of resistant strains of pathogens and the overgrowth of potentially dangerous species such as Clostridium difficile, but also, possibly, to prevent the loss of diversity in the human microbiome and thus discourage the development of chronic diseases.

In the future, as we discover more about the microbiome and the optimal mix of bacteria to carry, this information may find practical application in medicine. A pediatrician, for example, may want to analyze a child’s microbiome and, if it is abnormal, administer specific organisms to reshape it.

Recent years have seen dramatic increases in the prevalences of chronic diseases such as type 1 diabetes,¹ gastroesophageal reflux disease,² asthma,³ inflammatory bowel disease,⁴ and, notably, obesity.⁵ I propose the hypothesis that much of this increase may be due to loss of diversity in the bacteria that make our guts their home.⁶ While multiple causes contribute, much of the blame may be attributed to the use—and overuse—of antibiotics.

FAT AND GETTING FATTER

Today, nearly 40% of US adults are obese, and nearly three-fourths are either obese or overweight.⁷ More alarming, the prevalence of obesity is also high and getting higher in children and adolescents,⁸ having increased from 10.0% in 1988–1994 to 17.8% in 2013–2016.

And not just in the United States. Trends in weight have been going up around the world, with a lag of about 30 years between developing countries and industrialized countries.5

OUR BACTERIA, OURSELVES

I believe that the bacteria we carry are not random, but rather have coevolved along with us, passed down from generation to generation in a state of dynamic equilibrium between microbes and host. Evidence supporting this comes from a study by Ochman et al,⁹ who analyzed the DNA from fecal samples from different hominid species (including Homo sapiens) and found that the phylogenic relationships among the bacteria mirrored those among the apes.

Interacting with each other and with us in complex ways, our bacteria are a diverse community to which we can apply the term microbiome. They are acquired in a standard, choreographed process,¹⁰ and their composition comes to resemble that of adults by the age of 3.¹¹

Before modern times, microbes were transferred from mother to child during vaginal birth, from the mother’s breast during nursing, through skin-to-skin contact, and from the mother’s mouth by kissing. Now, widespread cesarean delivery, bottle-feeding, extensive bathing (especially with antibacterial soaps), and especially the use of antibiotics have changed the human ecology and altered transmission and maintenance of ancestral microbes, which affects the composition of the microbiota. The microbes, both good and bad, that are usually acquired early in life are especially important, since they affect a developmentally critical stage.¹²

Loss of microbial diversity in the mother appears to be cumulative over succeeding generations.¹³ For example, in a study in Japanese families, Urita et al¹⁴ found a decline in the prevalence of Helicobacter pylori colonization from 68.7% in the first generation to 43.4% in the second generation and 12.5% in the third. Clemente et al¹⁵ studied the intestinal microbiota in a previously uncontacted group of Yanomami people in the Amazon jungle and found they had the highest diversity of bacteria ever reported in a human group. By comparison, the research team calculated that we in the United States have already lost 50% of our microbial diversity, and 2 other groups, the Guahibo (another Amerindian group) and rural Malawians, were in between. More recent studies are confirming these observations.^16,17

 

 

USE AND OVERUSE OF ANTIBIOTICS

More than 73 billion antibiotic doses are prescribed worldwide yearly,¹⁸ or about 10 doses for every man, woman, and child on Earth, and the numbers are rising. In the United States 262 million courses were prescribed in 2011, or 842 per 1,000 population.¹⁹ Children receive a mean of 2.7 courses by age 2, and 10.9 by age 10. More than 50% of women receive antibiotics during pregnancy or perinatally. This is in addition to an unknown level of exposure from agricultural use of antibiotics.

Repeated antibiotic exposure is common in early life, varies widely by country, and is often not medically justified.²⁰ In the United States, antibiotic use varies by region, with the heaviest use in the South.^19,21 It also varies widely among prescribers.²² Jones et al²³ examined antibiotic prescribing for acute respiratory infections in US veterans and found that the top 10% of physicians gave an antibiotic more than 90% of the time. Physicians in Sweden prescribe about 60% fewer antibiotics than we do in the United States.^21,24

Observational data indicate that people who receive antibiotics have a higher risk of chronic diseases later in life, eg:

• Type 2 diabetes (odds ratio 1.21, 95% confidence interval 1.19–1.23 with 2 to 4 courses, and odds ratio 1.53 (1.50–1.55) with 5 or more courses, up to 15 years after²⁵
• Obesity: US states with the highest prevalence of antibiotic use also have the highest prevalence of obesity²⁶
• Kidney stones: prior antibiotic exposure in a large UK study was associated with increased kidney stone risk, for exposures up to 5 years earlier.²⁷

The meat industry has exploited the weight effect for decades, adding subtherapeutic doses of antibiotics to animals’ feed to make them gain weight.²8

FINDINGS FROM STUDIES IN MICE

Laboratory studies of the relationship between antibiotic exposure and disease phenotypes in mice have yielded interesting findings.

Mice exposed to antibiotics had more body fat at 10 weeks (32.0%) than control mice (22.9%).²⁹

Low-dose penicillin, started at birth, induces long-lasting effects on the expression of genes involved in immunity and enhances the effect of a high-fat diet in terms of weight gain.³⁰ If the antibiotic exposure is limited to early life, the effect on the microbiota is transient, but the mice still gain weight. If the microbiota from the mice who received penicillin is transferred to germ-free mice, the recipients also become fat, indicating that the bacteria, not the antibiotics per se, cause the weight gain.

In other experiments,³¹ a series of short, therapeutic doses of antibiotics early in life modeled after those given to children to treat their acute infections caused long-term changes in the composition of the microbiome and in metabolism.

A single course of a macrolide antibiotic also had long-term effects on the microbial population and on the host’s ileal gene expression, T-cell populations, and secretory immunoglobulin A expression.³² These effects were seen only in mice that had a microbiome to begin with, not in germ-free mice, indicating that the antibiotics had their effect through the changes in the microbiome, not directly. But when germ-free mice received a fecal transplant of an impaired microbiome, it was sufficient to affect immunity.

In nonobese diabetic mice, treatment with antibiotics early in life altered the gut microbiome and its metabolic capacities, intestinal gene expression, and T-cell populations, accelerating the onset of type 1 diabetes.³³

In a study in Danish children,³⁴ the likelihood of inflammatory bowel disease increased with early-life antibiotic exposure: the more courses the child received, the greater the likelihood of disease. This observation led researchers to wonder if an antibiotic-altered microbiome affects the outcome of inflammatory bowel disease in the next generation.³⁵ Germ-free female mice who received microbiota from mice who had received antibiotics passed the altered microbiome to their pups. Mice lacking the gene for interleukin 10 are genetically susceptible to colitis, and when this experiment was done in mice lacking this gene, the offspring developed markedly more colitis. This indicated the mothers could pass down their altered microbiome to the next generation and that it would affect their risk of disease.

WHAT CAN WE DO?

All physicians must adhere to the principles of antibiotic stewardship,³⁶ not only to prevent the development of resistant strains of pathogens and the overgrowth of potentially dangerous species such as Clostridium difficile, but also, possibly, to prevent the loss of diversity in the human microbiome and thus discourage the development of chronic diseases.

In the future, as we discover more about the microbiome and the optimal mix of bacteria to carry, this information may find practical application in medicine. A pediatrician, for example, may want to analyze a child’s microbiome and, if it is abnormal, administer specific organisms to reshape it.

The SVS Executive Board has announced that all Active SVS members in good standing will now be considered Fellows of the Society for Vascular Surgery™ (FSVS™). The trademarked designation is one of the benefits of SVS membership and is a public acknowledgement that a surgeon has met the high standards required by the SVS of its members and has shown and professional commitment to the field of vascular surgery. Active members in good standing may add the initials FSVS™ after their name in any usage, such as signature lines, letterhead, door signage and so on. Distinguished Fellows also may use the trademarked designation of DFSVS™. Read the official announcement here.

The SVS Executive Board has announced that all Active SVS members in good standing will now be considered Fellows of the Society for Vascular Surgery™ (FSVS™). The trademarked designation is one of the benefits of SVS membership and is a public acknowledgement that a surgeon has met the high standards required by the SVS of its members and has shown and professional commitment to the field of vascular surgery. Active members in good standing may add the initials FSVS™ after their name in any usage, such as signature lines, letterhead, door signage and so on. Distinguished Fellows also may use the trademarked designation of DFSVS™. Read the official announcement here.

The SVS Executive Board has announced that all Active SVS members in good standing will now be considered Fellows of the Society for Vascular Surgery™ (FSVS™). The trademarked designation is one of the benefits of SVS membership and is a public acknowledgement that a surgeon has met the high standards required by the SVS of its members and has shown and professional commitment to the field of vascular surgery. Active members in good standing may add the initials FSVS™ after their name in any usage, such as signature lines, letterhead, door signage and so on. Distinguished Fellows also may use the trademarked designation of DFSVS™. Read the official announcement here.

With intensive insulin regimens and home blood glucose monitoring, patients with type 1 diabetes are controlling their blood glucose better than in the past. Nevertheless, glucose regulation is still imperfect and tedious, and striving for tight glycemic control poses the risk of hypoglycemia.

Prominent among the challenges are the sheer numbers involved. Some 1.25 million Americans have type 1 diabetes, and another 30 million have type 2, but only about 7,000 to 8,000 pancreases are available for transplant each year.¹ While awaiting a breakthrough—perhaps involving stem cells, perhaps involving organs obtained from animals—an insulin pump may offer better diabetes control for many. Another possibility is a closed-loop system with a continuous glucose monitor that drives a dual-infusion pump, delivering insulin when glucose levels rise too high, and glucagon when they dip too low.

DIABETES WAS KNOWN IN ANCIENT TIMES

About 3,000 years ago, Egyptians described the syndrome of thirst, emaciation, and sweet urine that attracted ants. The term diabetes (Greek for siphon) was first recorded in 1425; mellitus (Latin for sweet with honey) was not added until 1675.

In 1857, Bernard hypothesized that diabetes was caused by overproduction of glucose in the liver. This idea was replaced in 1889, when Mering and Minkowski proposed the dysfunctional pancreas theory that eventually led to the discovery of the beta cell.²

In 1921, Banting and Best isolated insulin, and for the past 100 years subcutaneous insulin replacement has been the mainstay of treatment. But starting about 50 years ago, researchers have been looking for safe and long-lasting ways to replace beta cells and eliminate the need for exogenous insulin replacement.

TRANSPLANTING THE WHOLE PANCREAS

The first whole-pancreas transplant was performed in 1966 by Kelly et al,³ followed by 13 more by 1973.⁴ These first transplant grafts were short-lived, with only 1 graft surviving longer than 1 year. Since then, more than 12,000 pancreases have been transplanted worldwide, as refinements in surgical techniques and immunosuppressive therapies have improved patient and graft survival rates.⁴

Today, most pancreas transplants are in patients who have both type 1 diabetes and end-stage renal disease due to diabetic neph­ropathy, and most receive both a kidney and a pancreas at the same time. Far fewer patients receive a pancreas after previously receiving a kidney, or receive a pancreas alone.

The bile duct of the transplanted pancreas is usually routed into the patient’s small intestine, as nature intended, and less often into the bladder. Although bladder drainage is associated with urinary complications, it has the advantage of allowing measurement of pancreatic amylase levels in the urine to monitor for graft rejection. With simultaneous pancreas and kidney transplant, the serum creatinine concentration can also be monitored for rejection of the kidney graft.

Current immunosuppressive regimens vary but generally consist of anti-T-cell antibodies at the time of surgery, followed by lifelong treatment with the combination of a calcineurin inhibitor (cyclosporine or tacrolimus) and an antimetabolite (mycophenolate mofetil or azathioprine).

Outcomes are good. The rates of patient and graft survival are highest with simultaneous pancreas-kidney transplant, and somewhat lower with pancreas-after-kidney and pancreas-alone transplant.

Benefits of pancreas transplant

Most recipients can stop taking insulin immediately after the procedure, and their hemoglobin A_1c levels normalize and stay low for the life of the graft. Lipid levels also decrease, although this has not been directly correlated with lower risk of vascular disease.⁴

Transplant also reduces or eliminates some complications of diabetes, including retinopathy, nephropathy, cardiomyopathy, and gastropathy.

For example, in patients undergoing simultaneous pancreas-kidney transplant, diabetic nephropathy does not recur in the new kidney. Fioretto et al⁵ reported that nephropathy lesions reversed during the 10 years after pancreas transplant.

Kennedy et al^6,7 found that preexisting diabetic neuropathy improved slightly (although neurologic status did not completely return to normal) over a period of up to 42 months in a group of patients who received a pancreas transplant, whereas it tended to worsen in a control group. Both groups were assessed at baseline and at 12 and 24 months, with a subgroup followed through 42 months, and they underwent testing of motor, sensory, and autonomic function.^6,7

Disadvantages of pancreas transplant

Disadvantages of whole-pancreas transplant include hypoglycemia (usually mild), adverse effects of immunosuppression, potential for surgical complications including an increased rate of death in the first 90 days after the procedure, and cost.

In an analysis comparing the 5-year estimated costs of dialysis, kidney transplant alone from cadavers or live donors, or simultaneous pancreas-kidney transplant for diabetic patients with end-stage renal disease, the least expensive option was kidney transplant from a live donor.⁸ The most expensive option was simultaneous pancreas-kidney transplant, but quality of life was better with this option. The analysis did not consider the potential cost of long-term treatments for complications related to diabetes that could be saved with a pancreas transplant.

Data conflict regarding the risk of death with different types of pancreas transplants. A retrospective cohort study of data from 124 US transplant centers reported in 2003 found higher mortality rates in pancreas-alone transplant recipients than in patients on a transplant waiting list receiving conventional therapy.⁹ In contrast, a 2004 study reported that after the first 90 days, when the risk of death was clearly higher, mortality rates were lower after simultaneous pancreas-kidney transplant and pancreas-after-kidney transplant.¹⁰ After pancreas-alone transplant, however, mortality rates were higher than with exogenous insulin therapy.

Although outcomes have improved, fewer patients with type 1 diabetes are undergoing pancreas transplant in recent years.

Interestingly, more simultaneous pancreas-kidney transplants are being successfully performed in patients with type 2 diabetes, who now account for 8% of all simultaneous pancreas-kidney transplant recipients.¹¹ Outcomes of pancreas transplant appear to be similar regardless of diabetes type.

Bottom line

Pancreas transplant is a viable option for certain cases of complicated diabetes.

TRANSPLANTING ISLET CELLS

Despite its successes, pancreas transplant is major surgery and requires lifetime immunosuppression. Research is ongoing into a less-invasive procedure that, it is hoped, would require less immunosuppression: transplanting islets by themselves.

Islet autotransplant after pancreatectomy

For some patients with chronic pancreatitis, the only option to relieve chronic pain, narcotic dependence, and poor quality of life is to remove the pancreas. In the past, this desperate measure would instantly and inevitably cause diabetes, but not anymore.

Alpha cells and glucagon are a different story; a complication of islet transplant is hypoglycemia. In 2016, Lin et al¹² reported spontaneous hypoglycemia in 6 of 12 patients who maintained insulin independence after autotransplant of islets. Although the transplanted islets had functional alpha cells that could in theory produce glucagon, as well as beta cells that produce insulin and C-peptide, apparently the alpha cells were not secreting glucagon in response to the hypoglycemia.

Location may matter. Gupta et al,¹³ in a 1997 study in dogs, found that more hypoglycemia occurs if islets are autotransplanted into the liver than if they are transplanted into the peritoneal cavity. A possible explanation may have to do with the glycemic environment of the liver.

Islet allotransplant

Islets can also be taken from cadaver donors and transplanted into patients with type 1 diabetes, who do not have enough working beta cells.

Success of allotransplant increased after the publication of observational data from the program in Edmonton in Canada, in which 7 consecutive patients with type 1 diabetes achieved initial insulin independence after islet allotransplant using steroid-free immunosuppression.¹⁴ Six recipients required islets from 2 donors, and 1 required islets from 4 donors, so they all received large volumes of at least 11,000 islet equivalents (IEQ) per kilogram of body weight.

In a subsequent report from the same team,¹⁵ 16 (44%) of 36 patients remained insulin-free at 1 year, and C-peptide secretion was detectable in 70% at 2 years. But despite the elevated C-peptide levels, only 5 patients remained insulin-independent by 2 years. Lower hemoglobin A_1c levels and decreases in hypoglycemic events from baseline also were noted.

The Clinical Islet Transplantation Consortium (CITC)¹⁶ and Collaborative Islet Transplant Registry (CITR)¹⁷ were established in 2004 to combine data and resources from centers around the world, including several that specialize in islet isolation and purification. Currently, more than 80 studies are being conducted.

The CITC and CITR now have data on more than 1,000 allogeneic islet transplant recipients (islet transplant alone, after kidney transplant, or simultaneous with it). The primary outcomes are hemoglobin A_1c levels below 7% fasting C-peptide levels 0.3 ng/mL or higher, and fasting blood glucose of 60 to 140 mg/dL with no severe hypoglycemic events. The best results for islet-alone transplant have been in recipients over age 35 who received at least 325,000 IEQs with use of tumor necrosis factor antagonists for induction and calcineurin inhibitors or mammalian target of rapamycin (mTOR) inhibitors for maintenance.¹⁷

The best success for islet-after-kidney transplant was achieved with the same protocol but with insulin given to the donor during hospitalization before pancreas procurement. For participants with favorable factors, a hemoglobin A_1c at or below 6.5% was achieved in about 80% at 1 year after last infusion, with more than 80% maintaining their fasting blood glucose level goals. About 70% of these patients were insulin-independent at 1 year. Hypoglycemia unawareness resolved in these patients even 5 years after infusion. Although there were no deaths or disabilities related to these transplants, bleeding occurred in 1 of 15 procedures. There was also a notable decline in estimated glomerular filtration rates with calcineurin inhibitor-based immunosuppression.¹⁷

Making islets go farther

One of the greatest challenges to islet transplant is the need for multiple donors to provide enough islet cells to overcome the loss of cells during transplant. Pancreases are already in short supply, and if each recipient needs more than 1, this makes the shortage worse. Some centers have achieved transplant with fewer donors,^18,19 possibly by selecting pancreases from young donors who had a high body mass index and more islet cells, and harvesting and using them with a shorter cold ischemic time.

The number of viable, functioning islet cells drastically decreases after transplant, especially when transplanted into the portal system. This phenomenon is linked to an instant, blood-mediated inflammatory reaction involving antibody binding, complement and coagulation cascade activation, and platelet aggregation. The reaction, part of the innate immune system, damages the islet cells and leads to insulin dumping and early graft loss in studies in vitro and in vivo. Another factor affecting the survival of the graft cells is the low oxygen tension in the portal system.

For this reason, sites such as the pancreas, gastric submucosa, genitourinary tract, muscle, omentum, bone marrow, kidney capsule, peritoneum, anterior eye chamber, testis, and thymus are being explored.²⁰

To create a more supportive environment for the transplanted cells, biotechnicians are trying to encapsulate islets in a semipermeable membrane that would protect them from the immune system while still allowing oxygen, nutrients, waste products, and, critically, insulin to diffuse in and out. Currently, no site or encapsulated product has been more successful than the current practice of implanting naked islets in the portal system.²⁰

Bottom line

Without advances in transplant sites or increasing the yield of islet cells to allow single-donor transplants, islet cell allotransplant will not be feasible for most patients with type 1 diabetes.

Xenotransplant: Can pig cells make up the shortage?

Use of animal kidneys (xenotransplant) is a potential solution to the shortage of human organs for transplant.

In theory, pigs could be a source. Porcine insulin is similar to human insulin (differing by only 1 amino acid), and it should be possible to breed “knockout” pigs that lack the antigens responsible for acute humoral rejection.²¹

On the other hand, transplant of porcine islets poses several immunologic, physiologic, ethical, legal, and infectious concerns. For example, porcine tissue could carry pig viruses, such as porcine endogenous retroviruses.²¹ And even if the pigs are genetically modified, patients will still require immunosuppressive therapy.

A review of 17 studies of pig islet xenotransplant into nonhuman primates found that in 5 of the studies (4 using diabetic primates) the grafts survived at least 3 months.²² Of these, 1 study used encapsulation, and the rest used intensive and toxic immunosuppression.

More research is needed to make xenotransplant a clinical option.

Transplanting stem cells or beta cells grown from stem cells

Stem cells provide an exciting potential alternative to the limited donor pool. During the past decade, several studies have shown success using human pluripotent stem cells (embryonic stem cells and human-induced pluripotent stem cells), mesenchymal stem cells isolated from adult tissues, and directly programmed somatic cells. Researchers have created stable cultures of pluripotent stem cells from embryonic stem cells, which could possibly be produced on a large scale and banked.²³

Human pluripotent stem cells derived from pancreatic progenitors have been shown to mature into more functional, islet-like structures in vivo. They transform into subtypes of islet cells including alpha, beta, and delta cells, ghrelin-producing cells, and pancreatic polypeptide hormone-producing cells. This process takes 2 to 6 weeks. In mice, these cells have been shown to maintain glucose homeostasis.²⁴ Phase 1 and 2 trials in humans are now being conducted.

Pagliuca et al²⁵ generated functional human pancreatic beta cells in vitro from embryonic stem cells. Rezania et al²⁴ reversed diabetes with insulin-producing cells derived in vitro from human pluripotent stem cells. The techniques used in these studies contributed to the success of a study by Vegas et al,²⁶ who achieved successful long-term glycemic control in mice using polymer-encapsulated human stem cell-derived beta cells.

Reversal of autoimmunity is an important step that needs to be overcome in stem cell transplant for type 1 diabetes. Nikolic et al²⁷ have achieved mixed allogeneic chimerism across major histocompatibility complex barriers with nonmyeloablative conditioning in advanced-diabetic nonobese diabetic mice. However, conditioning alone (ie, without bone marrow transplant) does not permit acceptance of allogeneic islets and does not reverse autoimmunity or allow islet regeneration.²⁸ Adding allogeneic bone marrow transplant to conditioned nonobese diabetic mice leads to tolerance to the donor and reverses autoimmunity.

THE ‘BIONIC’ PANCREAS

While we wait for advances in islet cell transplant, improved insulin pumps hold promise.

One such experimental device, the iLet (Beta Bionics, Boston, MA), designed by Damiano et al, consists of 2 infusion pumps (1 for insulin, 1 for glucagon) linked to a continuous glucose monitor via a smartphone app.

The monitor measures the glucose level every 5 minutes and transmits the information wirelessly to the phone app, which calculates the amount of insulin and glucagon required to stabilize the blood glucose: more insulin if too high, more glucagon if too low. The phone transmits this information to the pumps.

Dubbed the “bionic” pancreas, this closed-loop system frees patients from the tasks of measuring their glucose multiple times a day, calculating the appropriate dose, and giving multiple insulin injections.

The 2016 summer camp study²⁹ followed 19 preteens wearing the bionic pancreas for 5 days. During this time, the patients had lower mean glucose levels and less hypoglycemia than during control periods. No episodes of severe hypoglycemia were recorded.

El-Khatib et al³⁰ randomly assigned 43 patients to treatment with either the bihormonal bionic pancreas or usual care (a conventional insulin pump or a sensor-augmented insulin pump) for 11 days, followed by 11 days of the opposite treatment. All participants continued their normal activities. The bionic pancreas system was superior to the insulin pump in terms of the mean glucose concentration and mean time in the hypoglycemic range (P < .0001 for both results).

Bottom line

As the search continues for better solutions, advances in technology such as the bionic pancreas could provide a safer (ie, less hypoglycemic) and more successful alternative for insulin replacement in the near future.

With intensive insulin regimens and home blood glucose monitoring, patients with type 1 diabetes are controlling their blood glucose better than in the past. Nevertheless, glucose regulation is still imperfect and tedious, and striving for tight glycemic control poses the risk of hypoglycemia.

Prominent among the challenges are the sheer numbers involved. Some 1.25 million Americans have type 1 diabetes, and another 30 million have type 2, but only about 7,000 to 8,000 pancreases are available for transplant each year.¹ While awaiting a breakthrough—perhaps involving stem cells, perhaps involving organs obtained from animals—an insulin pump may offer better diabetes control for many. Another possibility is a closed-loop system with a continuous glucose monitor that drives a dual-infusion pump, delivering insulin when glucose levels rise too high, and glucagon when they dip too low.

DIABETES WAS KNOWN IN ANCIENT TIMES

About 3,000 years ago, Egyptians described the syndrome of thirst, emaciation, and sweet urine that attracted ants. The term diabetes (Greek for siphon) was first recorded in 1425; mellitus (Latin for sweet with honey) was not added until 1675.

In 1857, Bernard hypothesized that diabetes was caused by overproduction of glucose in the liver. This idea was replaced in 1889, when Mering and Minkowski proposed the dysfunctional pancreas theory that eventually led to the discovery of the beta cell.²

In 1921, Banting and Best isolated insulin, and for the past 100 years subcutaneous insulin replacement has been the mainstay of treatment. But starting about 50 years ago, researchers have been looking for safe and long-lasting ways to replace beta cells and eliminate the need for exogenous insulin replacement.

TRANSPLANTING THE WHOLE PANCREAS

The first whole-pancreas transplant was performed in 1966 by Kelly et al,³ followed by 13 more by 1973.⁴ These first transplant grafts were short-lived, with only 1 graft surviving longer than 1 year. Since then, more than 12,000 pancreases have been transplanted worldwide, as refinements in surgical techniques and immunosuppressive therapies have improved patient and graft survival rates.⁴

Today, most pancreas transplants are in patients who have both type 1 diabetes and end-stage renal disease due to diabetic neph­ropathy, and most receive both a kidney and a pancreas at the same time. Far fewer patients receive a pancreas after previously receiving a kidney, or receive a pancreas alone.

The bile duct of the transplanted pancreas is usually routed into the patient’s small intestine, as nature intended, and less often into the bladder. Although bladder drainage is associated with urinary complications, it has the advantage of allowing measurement of pancreatic amylase levels in the urine to monitor for graft rejection. With simultaneous pancreas and kidney transplant, the serum creatinine concentration can also be monitored for rejection of the kidney graft.

Current immunosuppressive regimens vary but generally consist of anti-T-cell antibodies at the time of surgery, followed by lifelong treatment with the combination of a calcineurin inhibitor (cyclosporine or tacrolimus) and an antimetabolite (mycophenolate mofetil or azathioprine).

Outcomes are good. The rates of patient and graft survival are highest with simultaneous pancreas-kidney transplant, and somewhat lower with pancreas-after-kidney and pancreas-alone transplant.

Benefits of pancreas transplant

Most recipients can stop taking insulin immediately after the procedure, and their hemoglobin A_1c levels normalize and stay low for the life of the graft. Lipid levels also decrease, although this has not been directly correlated with lower risk of vascular disease.⁴

Transplant also reduces or eliminates some complications of diabetes, including retinopathy, nephropathy, cardiomyopathy, and gastropathy.

For example, in patients undergoing simultaneous pancreas-kidney transplant, diabetic nephropathy does not recur in the new kidney. Fioretto et al⁵ reported that nephropathy lesions reversed during the 10 years after pancreas transplant.

Kennedy et al^6,7 found that preexisting diabetic neuropathy improved slightly (although neurologic status did not completely return to normal) over a period of up to 42 months in a group of patients who received a pancreas transplant, whereas it tended to worsen in a control group. Both groups were assessed at baseline and at 12 and 24 months, with a subgroup followed through 42 months, and they underwent testing of motor, sensory, and autonomic function.^6,7

Disadvantages of pancreas transplant

Disadvantages of whole-pancreas transplant include hypoglycemia (usually mild), adverse effects of immunosuppression, potential for surgical complications including an increased rate of death in the first 90 days after the procedure, and cost.

In an analysis comparing the 5-year estimated costs of dialysis, kidney transplant alone from cadavers or live donors, or simultaneous pancreas-kidney transplant for diabetic patients with end-stage renal disease, the least expensive option was kidney transplant from a live donor.⁸ The most expensive option was simultaneous pancreas-kidney transplant, but quality of life was better with this option. The analysis did not consider the potential cost of long-term treatments for complications related to diabetes that could be saved with a pancreas transplant.

Data conflict regarding the risk of death with different types of pancreas transplants. A retrospective cohort study of data from 124 US transplant centers reported in 2003 found higher mortality rates in pancreas-alone transplant recipients than in patients on a transplant waiting list receiving conventional therapy.⁹ In contrast, a 2004 study reported that after the first 90 days, when the risk of death was clearly higher, mortality rates were lower after simultaneous pancreas-kidney transplant and pancreas-after-kidney transplant.¹⁰ After pancreas-alone transplant, however, mortality rates were higher than with exogenous insulin therapy.

Although outcomes have improved, fewer patients with type 1 diabetes are undergoing pancreas transplant in recent years.

Interestingly, more simultaneous pancreas-kidney transplants are being successfully performed in patients with type 2 diabetes, who now account for 8% of all simultaneous pancreas-kidney transplant recipients.¹¹ Outcomes of pancreas transplant appear to be similar regardless of diabetes type.

Bottom line

Pancreas transplant is a viable option for certain cases of complicated diabetes.

TRANSPLANTING ISLET CELLS

Despite its successes, pancreas transplant is major surgery and requires lifetime immunosuppression. Research is ongoing into a less-invasive procedure that, it is hoped, would require less immunosuppression: transplanting islets by themselves.

Islet autotransplant after pancreatectomy

For some patients with chronic pancreatitis, the only option to relieve chronic pain, narcotic dependence, and poor quality of life is to remove the pancreas. In the past, this desperate measure would instantly and inevitably cause diabetes, but not anymore.

Alpha cells and glucagon are a different story; a complication of islet transplant is hypoglycemia. In 2016, Lin et al¹² reported spontaneous hypoglycemia in 6 of 12 patients who maintained insulin independence after autotransplant of islets. Although the transplanted islets had functional alpha cells that could in theory produce glucagon, as well as beta cells that produce insulin and C-peptide, apparently the alpha cells were not secreting glucagon in response to the hypoglycemia.

Location may matter. Gupta et al,¹³ in a 1997 study in dogs, found that more hypoglycemia occurs if islets are autotransplanted into the liver than if they are transplanted into the peritoneal cavity. A possible explanation may have to do with the glycemic environment of the liver.

Islet allotransplant

Islets can also be taken from cadaver donors and transplanted into patients with type 1 diabetes, who do not have enough working beta cells.

Success of allotransplant increased after the publication of observational data from the program in Edmonton in Canada, in which 7 consecutive patients with type 1 diabetes achieved initial insulin independence after islet allotransplant using steroid-free immunosuppression.¹⁴ Six recipients required islets from 2 donors, and 1 required islets from 4 donors, so they all received large volumes of at least 11,000 islet equivalents (IEQ) per kilogram of body weight.

In a subsequent report from the same team,¹⁵ 16 (44%) of 36 patients remained insulin-free at 1 year, and C-peptide secretion was detectable in 70% at 2 years. But despite the elevated C-peptide levels, only 5 patients remained insulin-independent by 2 years. Lower hemoglobin A_1c levels and decreases in hypoglycemic events from baseline also were noted.

The Clinical Islet Transplantation Consortium (CITC)¹⁶ and Collaborative Islet Transplant Registry (CITR)¹⁷ were established in 2004 to combine data and resources from centers around the world, including several that specialize in islet isolation and purification. Currently, more than 80 studies are being conducted.

The CITC and CITR now have data on more than 1,000 allogeneic islet transplant recipients (islet transplant alone, after kidney transplant, or simultaneous with it). The primary outcomes are hemoglobin A_1c levels below 7% fasting C-peptide levels 0.3 ng/mL or higher, and fasting blood glucose of 60 to 140 mg/dL with no severe hypoglycemic events. The best results for islet-alone transplant have been in recipients over age 35 who received at least 325,000 IEQs with use of tumor necrosis factor antagonists for induction and calcineurin inhibitors or mammalian target of rapamycin (mTOR) inhibitors for maintenance.¹⁷

The best success for islet-after-kidney transplant was achieved with the same protocol but with insulin given to the donor during hospitalization before pancreas procurement. For participants with favorable factors, a hemoglobin A_1c at or below 6.5% was achieved in about 80% at 1 year after last infusion, with more than 80% maintaining their fasting blood glucose level goals. About 70% of these patients were insulin-independent at 1 year. Hypoglycemia unawareness resolved in these patients even 5 years after infusion. Although there were no deaths or disabilities related to these transplants, bleeding occurred in 1 of 15 procedures. There was also a notable decline in estimated glomerular filtration rates with calcineurin inhibitor-based immunosuppression.¹⁷

Making islets go farther

One of the greatest challenges to islet transplant is the need for multiple donors to provide enough islet cells to overcome the loss of cells during transplant. Pancreases are already in short supply, and if each recipient needs more than 1, this makes the shortage worse. Some centers have achieved transplant with fewer donors,^18,19 possibly by selecting pancreases from young donors who had a high body mass index and more islet cells, and harvesting and using them with a shorter cold ischemic time.

The number of viable, functioning islet cells drastically decreases after transplant, especially when transplanted into the portal system. This phenomenon is linked to an instant, blood-mediated inflammatory reaction involving antibody binding, complement and coagulation cascade activation, and platelet aggregation. The reaction, part of the innate immune system, damages the islet cells and leads to insulin dumping and early graft loss in studies in vitro and in vivo. Another factor affecting the survival of the graft cells is the low oxygen tension in the portal system.

For this reason, sites such as the pancreas, gastric submucosa, genitourinary tract, muscle, omentum, bone marrow, kidney capsule, peritoneum, anterior eye chamber, testis, and thymus are being explored.²⁰

To create a more supportive environment for the transplanted cells, biotechnicians are trying to encapsulate islets in a semipermeable membrane that would protect them from the immune system while still allowing oxygen, nutrients, waste products, and, critically, insulin to diffuse in and out. Currently, no site or encapsulated product has been more successful than the current practice of implanting naked islets in the portal system.²⁰

Bottom line

Without advances in transplant sites or increasing the yield of islet cells to allow single-donor transplants, islet cell allotransplant will not be feasible for most patients with type 1 diabetes.

Xenotransplant: Can pig cells make up the shortage?

Use of animal kidneys (xenotransplant) is a potential solution to the shortage of human organs for transplant.

In theory, pigs could be a source. Porcine insulin is similar to human insulin (differing by only 1 amino acid), and it should be possible to breed “knockout” pigs that lack the antigens responsible for acute humoral rejection.²¹

On the other hand, transplant of porcine islets poses several immunologic, physiologic, ethical, legal, and infectious concerns. For example, porcine tissue could carry pig viruses, such as porcine endogenous retroviruses.²¹ And even if the pigs are genetically modified, patients will still require immunosuppressive therapy.

A review of 17 studies of pig islet xenotransplant into nonhuman primates found that in 5 of the studies (4 using diabetic primates) the grafts survived at least 3 months.²² Of these, 1 study used encapsulation, and the rest used intensive and toxic immunosuppression.

More research is needed to make xenotransplant a clinical option.

Transplanting stem cells or beta cells grown from stem cells

Stem cells provide an exciting potential alternative to the limited donor pool. During the past decade, several studies have shown success using human pluripotent stem cells (embryonic stem cells and human-induced pluripotent stem cells), mesenchymal stem cells isolated from adult tissues, and directly programmed somatic cells. Researchers have created stable cultures of pluripotent stem cells from embryonic stem cells, which could possibly be produced on a large scale and banked.²³

Human pluripotent stem cells derived from pancreatic progenitors have been shown to mature into more functional, islet-like structures in vivo. They transform into subtypes of islet cells including alpha, beta, and delta cells, ghrelin-producing cells, and pancreatic polypeptide hormone-producing cells. This process takes 2 to 6 weeks. In mice, these cells have been shown to maintain glucose homeostasis.²⁴ Phase 1 and 2 trials in humans are now being conducted.

Pagliuca et al²⁵ generated functional human pancreatic beta cells in vitro from embryonic stem cells. Rezania et al²⁴ reversed diabetes with insulin-producing cells derived in vitro from human pluripotent stem cells. The techniques used in these studies contributed to the success of a study by Vegas et al,²⁶ who achieved successful long-term glycemic control in mice using polymer-encapsulated human stem cell-derived beta cells.

Reversal of autoimmunity is an important step that needs to be overcome in stem cell transplant for type 1 diabetes. Nikolic et al²⁷ have achieved mixed allogeneic chimerism across major histocompatibility complex barriers with nonmyeloablative conditioning in advanced-diabetic nonobese diabetic mice. However, conditioning alone (ie, without bone marrow transplant) does not permit acceptance of allogeneic islets and does not reverse autoimmunity or allow islet regeneration.²⁸ Adding allogeneic bone marrow transplant to conditioned nonobese diabetic mice leads to tolerance to the donor and reverses autoimmunity.

THE ‘BIONIC’ PANCREAS

While we wait for advances in islet cell transplant, improved insulin pumps hold promise.

One such experimental device, the iLet (Beta Bionics, Boston, MA), designed by Damiano et al, consists of 2 infusion pumps (1 for insulin, 1 for glucagon) linked to a continuous glucose monitor via a smartphone app.

The monitor measures the glucose level every 5 minutes and transmits the information wirelessly to the phone app, which calculates the amount of insulin and glucagon required to stabilize the blood glucose: more insulin if too high, more glucagon if too low. The phone transmits this information to the pumps.

Dubbed the “bionic” pancreas, this closed-loop system frees patients from the tasks of measuring their glucose multiple times a day, calculating the appropriate dose, and giving multiple insulin injections.

The 2016 summer camp study²⁹ followed 19 preteens wearing the bionic pancreas for 5 days. During this time, the patients had lower mean glucose levels and less hypoglycemia than during control periods. No episodes of severe hypoglycemia were recorded.

El-Khatib et al³⁰ randomly assigned 43 patients to treatment with either the bihormonal bionic pancreas or usual care (a conventional insulin pump or a sensor-augmented insulin pump) for 11 days, followed by 11 days of the opposite treatment. All participants continued their normal activities. The bionic pancreas system was superior to the insulin pump in terms of the mean glucose concentration and mean time in the hypoglycemic range (P < .0001 for both results).

Bottom line

As the search continues for better solutions, advances in technology such as the bionic pancreas could provide a safer (ie, less hypoglycemic) and more successful alternative for insulin replacement in the near future.

With intensive insulin regimens and home blood glucose monitoring, patients with type 1 diabetes are controlling their blood glucose better than in the past. Nevertheless, glucose regulation is still imperfect and tedious, and striving for tight glycemic control poses the risk of hypoglycemia.

Prominent among the challenges are the sheer numbers involved. Some 1.25 million Americans have type 1 diabetes, and another 30 million have type 2, but only about 7,000 to 8,000 pancreases are available for transplant each year.¹ While awaiting a breakthrough—perhaps involving stem cells, perhaps involving organs obtained from animals—an insulin pump may offer better diabetes control for many. Another possibility is a closed-loop system with a continuous glucose monitor that drives a dual-infusion pump, delivering insulin when glucose levels rise too high, and glucagon when they dip too low.

DIABETES WAS KNOWN IN ANCIENT TIMES

About 3,000 years ago, Egyptians described the syndrome of thirst, emaciation, and sweet urine that attracted ants. The term diabetes (Greek for siphon) was first recorded in 1425; mellitus (Latin for sweet with honey) was not added until 1675.

In 1857, Bernard hypothesized that diabetes was caused by overproduction of glucose in the liver. This idea was replaced in 1889, when Mering and Minkowski proposed the dysfunctional pancreas theory that eventually led to the discovery of the beta cell.²

In 1921, Banting and Best isolated insulin, and for the past 100 years subcutaneous insulin replacement has been the mainstay of treatment. But starting about 50 years ago, researchers have been looking for safe and long-lasting ways to replace beta cells and eliminate the need for exogenous insulin replacement.

TRANSPLANTING THE WHOLE PANCREAS

The first whole-pancreas transplant was performed in 1966 by Kelly et al,³ followed by 13 more by 1973.⁴ These first transplant grafts were short-lived, with only 1 graft surviving longer than 1 year. Since then, more than 12,000 pancreases have been transplanted worldwide, as refinements in surgical techniques and immunosuppressive therapies have improved patient and graft survival rates.⁴

Today, most pancreas transplants are in patients who have both type 1 diabetes and end-stage renal disease due to diabetic neph­ropathy, and most receive both a kidney and a pancreas at the same time. Far fewer patients receive a pancreas after previously receiving a kidney, or receive a pancreas alone.

The bile duct of the transplanted pancreas is usually routed into the patient’s small intestine, as nature intended, and less often into the bladder. Although bladder drainage is associated with urinary complications, it has the advantage of allowing measurement of pancreatic amylase levels in the urine to monitor for graft rejection. With simultaneous pancreas and kidney transplant, the serum creatinine concentration can also be monitored for rejection of the kidney graft.

Current immunosuppressive regimens vary but generally consist of anti-T-cell antibodies at the time of surgery, followed by lifelong treatment with the combination of a calcineurin inhibitor (cyclosporine or tacrolimus) and an antimetabolite (mycophenolate mofetil or azathioprine).

Outcomes are good. The rates of patient and graft survival are highest with simultaneous pancreas-kidney transplant, and somewhat lower with pancreas-after-kidney and pancreas-alone transplant.

Benefits of pancreas transplant

Most recipients can stop taking insulin immediately after the procedure, and their hemoglobin A_1c levels normalize and stay low for the life of the graft. Lipid levels also decrease, although this has not been directly correlated with lower risk of vascular disease.⁴

Transplant also reduces or eliminates some complications of diabetes, including retinopathy, nephropathy, cardiomyopathy, and gastropathy.

For example, in patients undergoing simultaneous pancreas-kidney transplant, diabetic nephropathy does not recur in the new kidney. Fioretto et al⁵ reported that nephropathy lesions reversed during the 10 years after pancreas transplant.

Kennedy et al^6,7 found that preexisting diabetic neuropathy improved slightly (although neurologic status did not completely return to normal) over a period of up to 42 months in a group of patients who received a pancreas transplant, whereas it tended to worsen in a control group. Both groups were assessed at baseline and at 12 and 24 months, with a subgroup followed through 42 months, and they underwent testing of motor, sensory, and autonomic function.^6,7

Disadvantages of pancreas transplant

Disadvantages of whole-pancreas transplant include hypoglycemia (usually mild), adverse effects of immunosuppression, potential for surgical complications including an increased rate of death in the first 90 days after the procedure, and cost.

In an analysis comparing the 5-year estimated costs of dialysis, kidney transplant alone from cadavers or live donors, or simultaneous pancreas-kidney transplant for diabetic patients with end-stage renal disease, the least expensive option was kidney transplant from a live donor.⁸ The most expensive option was simultaneous pancreas-kidney transplant, but quality of life was better with this option. The analysis did not consider the potential cost of long-term treatments for complications related to diabetes that could be saved with a pancreas transplant.

Data conflict regarding the risk of death with different types of pancreas transplants. A retrospective cohort study of data from 124 US transplant centers reported in 2003 found higher mortality rates in pancreas-alone transplant recipients than in patients on a transplant waiting list receiving conventional therapy.⁹ In contrast, a 2004 study reported that after the first 90 days, when the risk of death was clearly higher, mortality rates were lower after simultaneous pancreas-kidney transplant and pancreas-after-kidney transplant.¹⁰ After pancreas-alone transplant, however, mortality rates were higher than with exogenous insulin therapy.

Although outcomes have improved, fewer patients with type 1 diabetes are undergoing pancreas transplant in recent years.

Interestingly, more simultaneous pancreas-kidney transplants are being successfully performed in patients with type 2 diabetes, who now account for 8% of all simultaneous pancreas-kidney transplant recipients.¹¹ Outcomes of pancreas transplant appear to be similar regardless of diabetes type.

Bottom line

Pancreas transplant is a viable option for certain cases of complicated diabetes.

TRANSPLANTING ISLET CELLS

Despite its successes, pancreas transplant is major surgery and requires lifetime immunosuppression. Research is ongoing into a less-invasive procedure that, it is hoped, would require less immunosuppression: transplanting islets by themselves.

Islet autotransplant after pancreatectomy

For some patients with chronic pancreatitis, the only option to relieve chronic pain, narcotic dependence, and poor quality of life is to remove the pancreas. In the past, this desperate measure would instantly and inevitably cause diabetes, but not anymore.

Alpha cells and glucagon are a different story; a complication of islet transplant is hypoglycemia. In 2016, Lin et al¹² reported spontaneous hypoglycemia in 6 of 12 patients who maintained insulin independence after autotransplant of islets. Although the transplanted islets had functional alpha cells that could in theory produce glucagon, as well as beta cells that produce insulin and C-peptide, apparently the alpha cells were not secreting glucagon in response to the hypoglycemia.

Location may matter. Gupta et al,¹³ in a 1997 study in dogs, found that more hypoglycemia occurs if islets are autotransplanted into the liver than if they are transplanted into the peritoneal cavity. A possible explanation may have to do with the glycemic environment of the liver.

Islet allotransplant

Islets can also be taken from cadaver donors and transplanted into patients with type 1 diabetes, who do not have enough working beta cells.

Success of allotransplant increased after the publication of observational data from the program in Edmonton in Canada, in which 7 consecutive patients with type 1 diabetes achieved initial insulin independence after islet allotransplant using steroid-free immunosuppression.¹⁴ Six recipients required islets from 2 donors, and 1 required islets from 4 donors, so they all received large volumes of at least 11,000 islet equivalents (IEQ) per kilogram of body weight.

In a subsequent report from the same team,¹⁵ 16 (44%) of 36 patients remained insulin-free at 1 year, and C-peptide secretion was detectable in 70% at 2 years. But despite the elevated C-peptide levels, only 5 patients remained insulin-independent by 2 years. Lower hemoglobin A_1c levels and decreases in hypoglycemic events from baseline also were noted.

The Clinical Islet Transplantation Consortium (CITC)¹⁶ and Collaborative Islet Transplant Registry (CITR)¹⁷ were established in 2004 to combine data and resources from centers around the world, including several that specialize in islet isolation and purification. Currently, more than 80 studies are being conducted.

The CITC and CITR now have data on more than 1,000 allogeneic islet transplant recipients (islet transplant alone, after kidney transplant, or simultaneous with it). The primary outcomes are hemoglobin A_1c levels below 7% fasting C-peptide levels 0.3 ng/mL or higher, and fasting blood glucose of 60 to 140 mg/dL with no severe hypoglycemic events. The best results for islet-alone transplant have been in recipients over age 35 who received at least 325,000 IEQs with use of tumor necrosis factor antagonists for induction and calcineurin inhibitors or mammalian target of rapamycin (mTOR) inhibitors for maintenance.¹⁷

The best success for islet-after-kidney transplant was achieved with the same protocol but with insulin given to the donor during hospitalization before pancreas procurement. For participants with favorable factors, a hemoglobin A_1c at or below 6.5% was achieved in about 80% at 1 year after last infusion, with more than 80% maintaining their fasting blood glucose level goals. About 70% of these patients were insulin-independent at 1 year. Hypoglycemia unawareness resolved in these patients even 5 years after infusion. Although there were no deaths or disabilities related to these transplants, bleeding occurred in 1 of 15 procedures. There was also a notable decline in estimated glomerular filtration rates with calcineurin inhibitor-based immunosuppression.¹⁷

Making islets go farther

One of the greatest challenges to islet transplant is the need for multiple donors to provide enough islet cells to overcome the loss of cells during transplant. Pancreases are already in short supply, and if each recipient needs more than 1, this makes the shortage worse. Some centers have achieved transplant with fewer donors,^18,19 possibly by selecting pancreases from young donors who had a high body mass index and more islet cells, and harvesting and using them with a shorter cold ischemic time.

The number of viable, functioning islet cells drastically decreases after transplant, especially when transplanted into the portal system. This phenomenon is linked to an instant, blood-mediated inflammatory reaction involving antibody binding, complement and coagulation cascade activation, and platelet aggregation. The reaction, part of the innate immune system, damages the islet cells and leads to insulin dumping and early graft loss in studies in vitro and in vivo. Another factor affecting the survival of the graft cells is the low oxygen tension in the portal system.

For this reason, sites such as the pancreas, gastric submucosa, genitourinary tract, muscle, omentum, bone marrow, kidney capsule, peritoneum, anterior eye chamber, testis, and thymus are being explored.²⁰

To create a more supportive environment for the transplanted cells, biotechnicians are trying to encapsulate islets in a semipermeable membrane that would protect them from the immune system while still allowing oxygen, nutrients, waste products, and, critically, insulin to diffuse in and out. Currently, no site or encapsulated product has been more successful than the current practice of implanting naked islets in the portal system.²⁰

Bottom line

Without advances in transplant sites or increasing the yield of islet cells to allow single-donor transplants, islet cell allotransplant will not be feasible for most patients with type 1 diabetes.

Xenotransplant: Can pig cells make up the shortage?

Use of animal kidneys (xenotransplant) is a potential solution to the shortage of human organs for transplant.

In theory, pigs could be a source. Porcine insulin is similar to human insulin (differing by only 1 amino acid), and it should be possible to breed “knockout” pigs that lack the antigens responsible for acute humoral rejection.²¹

On the other hand, transplant of porcine islets poses several immunologic, physiologic, ethical, legal, and infectious concerns. For example, porcine tissue could carry pig viruses, such as porcine endogenous retroviruses.²¹ And even if the pigs are genetically modified, patients will still require immunosuppressive therapy.

A review of 17 studies of pig islet xenotransplant into nonhuman primates found that in 5 of the studies (4 using diabetic primates) the grafts survived at least 3 months.²² Of these, 1 study used encapsulation, and the rest used intensive and toxic immunosuppression.

More research is needed to make xenotransplant a clinical option.

Transplanting stem cells or beta cells grown from stem cells

Stem cells provide an exciting potential alternative to the limited donor pool. During the past decade, several studies have shown success using human pluripotent stem cells (embryonic stem cells and human-induced pluripotent stem cells), mesenchymal stem cells isolated from adult tissues, and directly programmed somatic cells. Researchers have created stable cultures of pluripotent stem cells from embryonic stem cells, which could possibly be produced on a large scale and banked.²³

Human pluripotent stem cells derived from pancreatic progenitors have been shown to mature into more functional, islet-like structures in vivo. They transform into subtypes of islet cells including alpha, beta, and delta cells, ghrelin-producing cells, and pancreatic polypeptide hormone-producing cells. This process takes 2 to 6 weeks. In mice, these cells have been shown to maintain glucose homeostasis.²⁴ Phase 1 and 2 trials in humans are now being conducted.

Pagliuca et al²⁵ generated functional human pancreatic beta cells in vitro from embryonic stem cells. Rezania et al²⁴ reversed diabetes with insulin-producing cells derived in vitro from human pluripotent stem cells. The techniques used in these studies contributed to the success of a study by Vegas et al,²⁶ who achieved successful long-term glycemic control in mice using polymer-encapsulated human stem cell-derived beta cells.

Reversal of autoimmunity is an important step that needs to be overcome in stem cell transplant for type 1 diabetes. Nikolic et al²⁷ have achieved mixed allogeneic chimerism across major histocompatibility complex barriers with nonmyeloablative conditioning in advanced-diabetic nonobese diabetic mice. However, conditioning alone (ie, without bone marrow transplant) does not permit acceptance of allogeneic islets and does not reverse autoimmunity or allow islet regeneration.²⁸ Adding allogeneic bone marrow transplant to conditioned nonobese diabetic mice leads to tolerance to the donor and reverses autoimmunity.

THE ‘BIONIC’ PANCREAS

While we wait for advances in islet cell transplant, improved insulin pumps hold promise.

One such experimental device, the iLet (Beta Bionics, Boston, MA), designed by Damiano et al, consists of 2 infusion pumps (1 for insulin, 1 for glucagon) linked to a continuous glucose monitor via a smartphone app.

The monitor measures the glucose level every 5 minutes and transmits the information wirelessly to the phone app, which calculates the amount of insulin and glucagon required to stabilize the blood glucose: more insulin if too high, more glucagon if too low. The phone transmits this information to the pumps.

Dubbed the “bionic” pancreas, this closed-loop system frees patients from the tasks of measuring their glucose multiple times a day, calculating the appropriate dose, and giving multiple insulin injections.

The 2016 summer camp study²⁹ followed 19 preteens wearing the bionic pancreas for 5 days. During this time, the patients had lower mean glucose levels and less hypoglycemia than during control periods. No episodes of severe hypoglycemia were recorded.

El-Khatib et al³⁰ randomly assigned 43 patients to treatment with either the bihormonal bionic pancreas or usual care (a conventional insulin pump or a sensor-augmented insulin pump) for 11 days, followed by 11 days of the opposite treatment. All participants continued their normal activities. The bionic pancreas system was superior to the insulin pump in terms of the mean glucose concentration and mean time in the hypoglycemic range (P < .0001 for both results).

Bottom line

As the search continues for better solutions, advances in technology such as the bionic pancreas could provide a safer (ie, less hypoglycemic) and more successful alternative for insulin replacement in the near future.

Marijuana, which is still illegal under federal law but legal in 30 states for medical purposes as of this writing, has shown promising results for treating peripheral neuropathy. Studies suggest that cannabis may be an option for patients whose pain responds poorly to standard treatments; however, its use may be restricted by cognitive and psychiatric adverse effects, particularly at high doses.¹

See related editorial

In this article, we discuss the basic pharmacology of cannabis and how it may affect neuropathic pain. We review clinical trials on its use for peripheral neuropathy and provide guidance for its use.

PERIPHERAL NEUROPATHY IS COMMON AND COMPLEX

An estimated 20 million people in the United States suffer from neuropathic pain. The prevalence is higher in certain populations, with 26% of people over age 65 and 30% of patients with diabetes mellitus affected.^2–4

Peripheral neuropathy is a complex, chronic state that occurs when nerve fibers are damaged, dysfunctional, or injured, sending incorrect signals to pain centers in the central nervous system.⁵ It is characterized by weakness, pain, and paresthesias that typically begin in the hands or feet and progress proximally.⁴ Symptoms depend on the number and types of nerves affected.

In many cases, peripheral neuropathy is idiopathic, but common causes include diabetes, alcoholism, human immunodeficiency virus (HIV) infection, and autoimmune disease. Others include toxicity from chemotherapy and heavy metals.

Peripheral neuropathy significantly worsens quality of life and function. Many patients experience emotional, cognitive, and functional problems, resulting in high rates of medical and psychiatric comorbidities and occupational impairment.^4,6,7 Yet despite its clinical and epidemiologic significance, it is often undertreated.⁸

STANDARD TREATMENTS INADEQUATE

Peripheral neuropathy occurs in patients with a wide range of comorbidities and is especially difficult to treat. Mainstays of therapy include anticonvulsants, tricyclic antidepressants, and serotonin-norepinephrine reuptake inhibitors.⁹ A more invasive option is spinal cord stimulation.

These treatments can have considerable adverse effects, and response rates remain suboptimal, with pain relief insufficient to improve quality of life for many patients.^9,10 Better treatments are needed to improve clinical outcomes and patient experience.¹¹

CANNABIS: A MIX OF COMPOUNDS

Cannabis sativa has been used as an analgesic for centuries. The plant contains more than 400 chemical compounds and is often used for its euphoric properties. Long-term use may lead to addiction and cognitive impairment.^12,13

Tetrahydrocannabinol (THC) and cannabidiol (CBD) are the main components and the 2 best-studied cannabinoids with analgesic effects.

THC is the primary psychoactive component of cannabis. Its effects include relaxation, altered perception, heightened sensations, increased libido, and perceptual distortions of time and space. Temporary effects may include decreased short-term memory, dry mouth, impaired motor function, conjunctival injection, paranoia, and anxiety.

CBD is nonpsychoactive and has anti-inflammatory and antioxidant properties. It has been shown to reduce pain and inflammation without the effects of THC.¹⁴

Other compounds in the cannabis plant include phytocannabinoids, flavonoids, and tapenoids, which may produce individual, interactive, or synergistic effects.¹⁵ Different strains of cannabis have varying amounts of the individual components, making comparisons among clinical studies difficult.

THE ENDOCANNABINOID SYSTEM

The endogenous mammalian cannabinoid system plays a regulatory role in the development, homeostasis, and neuroplasticity of the central nervous system. It is also involved in modulating pain transmission in the nociceptive pathway.

Two of the most abundant cannabinoid endogenous ligands are anandamide and 2-arachidonylglycerol.⁹ These endocanna­b­inoids are produced on demand in the central nervous system to reduce pain by acting as a circuit breaker.^16–18 They target the G protein-coupled cannabinoid receptors CB1 and CB2, located throughout the central and peripheral nervous system and in organs and tissues.¹²

CB1 receptors are found primarily in the central nervous system, specifically in areas involved in movement, such as the basal ganglia and cerebellum, as well as in areas involved in memory, such as the hippocampus.¹² They are also abundant in brain regions implicated in conducting and modulating pain signals, including the periaqueductal gray and the dorsal horn of the spinal cord.^16–20

CB2 receptors are mostly found in peripheral tissues and organs, mainly those involved in the immune system, including splenic, tonsillar, and hematopoietic cells.¹² They help regulate inflammation, allodynia, and hyperalgesia.¹⁷

Modifying response to injury

Following a nerve injury, neurons along the nociceptive pathway may become more reactive and responsive in a process known as sensitization.²¹ The process involves a cascade of cellular events that result in sprouting of pain-sensitive nerve endings.^21,22

Cannabinoids are thought to reduce pain by modifying these cellular events. They also inhibit nociceptive conduction in the dorsal horn of the spinal cord and in the ascending spinothalamic tract.²⁰ CB1 receptors found in nociceptive terminals along the peripheral nervous system impede pain conduction, while activation of CB2 receptors in immune cells decreases the release of nociceptive agents.

 

 

STUDIES OF CANNABIS FOR NEUROPATHIC PAIN

A number of studies have evaluated cannabis for treating neuropathic pain. Overall, available data support the efficacy of smoked or inhaled cannabis in its flower form when used as monotherapy or adjunctive therapy for relief of neuropathic pain of various etiologies. Many studies also report secondary benefits, including better sleep and functional improvement.^23,24

However, adverse effects are common, especially at high doses, and include difficulty concentrating, lightheadedness, fatigue, and tachycardia. More serious reported adverse effects include anxiety, paranoia, and psychosis.

Wilsey et al, 2008: Neuropathic pain reduced

Wilsey et al²⁵ conducted a double-blind, placebo-controlled crossover study that assessed the effects of smoking cannabis in 38 patients with central or peripheral neuropathic pain. Participants were assigned to smoke either high- or low-dose cannabis (7% or 3.5% delta-9-THC) or placebo cigarettes. Cigarettes were smoked during treatment sessions using the following regimen: 2 puffs at 60 minutes from baseline, 3 puffs at 120 minutes, and 4 puffs at 180 minutes. Patients were assessed after each set of puffs and for 2 hours afterwards. The primary outcome was spontaneous relief of pain as measured by a visual analog scale.

Pain intensity was comparable and significantly reduced in both treatment groups compared with placebo. At the high dose, some participants experienced neurocognitive impairment in attention, learning, memory, and psychomotor speed; only learning and memory declined at the low dose.

Ellis et al, 2009: Pain reduction in HIV neuropathy

Ellis et al²³ conducted a double-blind, placebo-controlled crossover trial in patients with HIV neuropathy that was unresponsive to at least 2 analgesics with different modes of action. During each treatment week, participants were randomly assigned to smoke either active cannabis or placebo, while continuing their standard therapy. Titration started at 4% THC and was adjusted based on tolerability and efficacy. Twenty-eight of the 34 enrolled patients completed both cannabis and placebo treatments. The principal outcome was change in pain intensity from baseline at the end of each week, using the Descriptor Differential Scale of Pain Intensity.

Of the 28 patients, 46% achieved an average pain reduction of 3.3 points (30%). One patient experienced cannabis-induced psychosis, and another developed an intractable cough, which resolved with smoking cessation.

Ware et al, 2010: Reduced posttraumatic or postsurgical neuropathic pain

Ware et al²⁴ performed a randomized crossover trial in 21 patients with posttraumatic or postsurgical neuropathic pain. Participants inhaled 4 different formulations of cannabis (containing 0%, 2.5%, 6.0%, and 9.4% THC) during 4 14-day periods. They inhaled a 25-mg dose through a pipe 3 times a day for the first 5 days of each cycle, followed by a 9-day washout period. Daily average pain intensity was measured using a numeric rating scale. The investigators also assessed mood, sleep, quality of life, and adverse effects.

Patients in the 9.4% THC group reported significantly less pain and better sleep, with average pain scores decreasing from 6.1 to 5.4 on an 11-point scale. Although the benefit was modest, the authors noted that the pain had been refractory to standard treatments.

The number of reported adverse events increased with greater potency and were most commonly throat irritation, burning sensation, headache, dizziness, and fatigue. This study suggests that THC potency affects tolerability, with higher doses eliciting clinically important adverse effects, some of which may reduce the ability to perform activities of daily living, such as driving.

Wilsey et al, 2013: Use in resistant neuropathic pain

Wilsey et al²⁶ conducted another double-blind, placebo-controlled crossover study assessing the effect of vaporized cannabis on central and peripheral neuropathic pain resistant to first-line pharmacotherapies. Dose-effect relationships were explored using medium-dose (3.5%), low-dose (1.3%), and placebo cannabis. The primary outcome measure was a 30% reduction in pain intensity based on a visual analog scale.

In the placebo group, 26% of patients achieved this vs 57% of the low-dose cannabis group and 61% of those receiving the medium dose. No significant difference was found between the 2 active doses in reducing neuropathic pain, and both were more effective than placebo. The number needed to treat to achieve a 30% reduction in pain was about 3 for both cannabis groups compared with placebo. Psychoactive effects were minimal, of short duration, and reversible.

Wallace et al, 2015: Use in diabetic peripheral neuropathy

Wallace et al²⁷ conducted a randomized, double-blind, placebo-controlled crossover study evaluating cannabis for diabetic peripheral neuropathy in 16 patients. Each had experienced at least 6 months of neuropathic pain in their feet. The participants inhaled a single dose of 1%, 4%, or 7% THC cannabis or placebo. Spontaneous pain was reported with a visual analog scale and also tested with a foam brush and von Frey filament at intervals until 4 hours after treatment.

Pain scores were lower with treatment compared with placebo, with high-dose cannabis having the greatest analgesic effect. Pain reduction lasted for the full duration of the test. Cannabis recipients had declines in attention and working memory, with the high-dose group experiencing the greatest impact 15 minutes after treatment. High-dose recipients also had poorer scores on testing of quick task-switching, with the greatest effect at 2 hours.²⁷

Research and market cannabis are not equal

Results of US studies must be qualified. Most have used cannabis provided by the National Institute of Drug Abuse (NIDA),^23–26 which differs in potency from commercially available preparations. This limits the clinical usefulness of the analysis of benefits and risks.

Vergara et al²⁸ found that NIDA varieties contained much lower THC levels and as much as 23 times the cannabinol content as cannabis in state-legalized markets.

Studies based on NIDA varieties likely underestimate the risks of consumer-purchased cannabis, as THC is believed to be most responsible for the risk of psychosis and impaired driving and cognition.^24,28

 

 

CBD MAY PROTECT AGAINST ADVERSE EFFECTS

Studies of CBD alone are limited to preclinical data.²⁹ Evidence suggests that CBD alone or combined with THC can suppress chronic neuropathic pain, and that CBD may have a protective effect after nerve injury.³⁰

Nabiximols, an oromucosal spray preparation with equal amounts of THC and CBD, has been approved in Canada as well as in European countries including the United Kingdom. Although its use has not been associated with many of the adverse effects of inhaled cannabis,^30–32 evidence of efficacy from clinical trials has been mixed.

Lynch et al,³¹ in a 2014 randomized, double-blind, placebo-controlled crossover pilot study³¹ evaluated nabiximols in 16 patients with neuropathic pain related to chemotherapy. No statistically significant difference was found between treatment and placebo. However, the trial was underpowered.

Serpell et al,³² in a 2014 European randomized, placebo-controlled parallel-group study, evaluated 246 patients with peripheral neuropathy with allodynia, with 128 receiving active treatment (THC-CBD oromucosal spray) and 118 receiving placebo. Over the 15-week study, participants continued their current analgesic treatments.

Pain was reduced in the treatment group, but the difference from placebo was not statistically significant. However, the treatment group reported significantly better sleep quality and Patient Global Impression of Change measures (reflecting a patient’s belief of treatment efficacy).

META-ANALYSES CONFIRM EFFECT

Three meta-analyses of available studies of the effects of cannabis on neuropathic pain have been completed.

Andreae et al, 2015: 5 trials, 178 patients

Andreae et al¹ evaluated 5 randomized controlled trials in 178 patients in North America. All had had neuropathy for at least 3 months, with a pain level of at least about 3 on a scale of 10. Two studies had patients with HIV-related neuropathy; the other 3 involved patients with neuropathy related to trauma, diabetes, complex regional pain syndrome, or spinal cord injury. All trials used whole cannabis plant provided by NIDA, and the main outcomes were patient-reported pain scales. No study evaluated pain beyond 2 weeks after trial termination.

They found that 1 of every 5 to 6 patients treated with cannabis had at least a 30% pain reduction.

Nugent et al, 2017: 13 trials, 246 patients

Nugent et al³³ reviewed 13 trials in 246 patients that evaluated the effects of different cannabis-based preparations on either central or peripheral neuropathic pain from various conditions. Actively treated patients were more likely to report a 30% improvement in neuropathic pain. Again, studies tended to be small and brief.

Cochrane review, 2018: 16 trials, 1,750 patients

A Cochrane review³⁴ analyzed 16 trials (in 1,750 patients) lasting 2 to 26 weeks. Treatments included an oromucosal spray with a plant-derived combination of THC and CBD, nabilone, inhaled herbal cannabis, and plant-derived THC.

With cannabis-based treatments, significantly more people achieved 50% or greater pain relief than with placebo (21% vs 17%, number needed to treat 20); 30% pain reduction was achieved in 39% of treated patients vs 33% of patients taking placebo (number needed to treat 11).

On the other hand, significantly more participants withdrew from studies because of adverse events with cannabis-based treatments than placebo (10% vs 5%), with psychiatric disorders occurring in 17% of patients receiving active treatment vs 5% of those receiving placebo (number needed to harm 10). 

The primary studies suffered from methodologic limitations including small size, short duration, and inconsistency of formulations and study designs. Further evaluation of long-term efficacy, tolerability, and addiction potential is critical to determine the risk-benefit ratio.

RISKS OF CANNABIS USE

Like any drug therapy, cannabis has effects that may limit its use. Cannabis can affect a person’s psyche, physiology, and lifestyle.

Impaired attention, task speed

Neurocognitive changes associated with cannabis use—especially dizziness, fatigue, and slowed task-switching—could affect driving and other complex tasks. Evidence indicates that such activities should be avoided in the hours after treatment.^26,27,32,33

Concern over brain development

Most worrisome is the effect of long-term cannabis use on brain development in young adults. Regular use of cannabis at an early age is associated with lower IQ, decline in school performance, and lower rates of high school graduation.³⁵

Avoid in psychiatric patients

It is unlikely that cannabis can be safely used in patients with psychiatric illnesses. Anxiety, depression, and psychotic disorders can be exacerbated by the regular use of cannabis, and the risk of developing these conditions is increased while using cannabis.^36,37

High concentrations of THC (the highest concentration used in the above studies was 9.5%) can cause anxiety, paranoia, and psychosis.

Respiratory effects

Long-term cannabis smoking may cause wheezing, cough, dyspnea, and exacerbations of chronic bronchitis. There is some evidence that symptoms improve after stopping smoking.^33,38

SHOULD WE RECOMMEND CANNABIS?

Where cannabis can be legally used, doctors should be familiar with the literature and its limitations so that they can counsel patients on the best use and potential risks and benefits of cannabis treatment.

A recent conceptualization of pain suggests that a pain score reflects a composite of sensory factors (eg, tissue damage), cognitive factors (eg, beliefs about pain), and affective factors (eg, anxiety, depression).³⁹ Physicians should keep this in mind when evaluating patients to better assess the risks and benefits of cannabis. While pharmacotherapy may address sensory factors, cognitive behavioral therapy may help alter beliefs about the pain as well as anxiety and depressive symptoms that might influence subjective reports.

Ideally, patients being considered for cannabis treatment would have a type of neuropathic pain proven to respond to cannabis in randomized, controlled studies, as well as evidence of failed first-line treatments.

Relative contraindications include depression, anxiety, substance use, psychotic disorders, and respiratory conditions, and these should also be considered.

Although current research shows an analgesic benefit of cannabis on neuropathic pain comparable to that of gabapentin,⁴⁰ further investigation is needed to better evaluate long-term safety, efficacy, and interactions with standard therapies. Until we have a more complete picture, we should use the current literature, along with a thorough knowledge of each patient, to determine if the benefits of cannabis therapy outweigh the risks.

Acknowledgments: We thank Camillo Ferrari, BS, and Christina McMahon, BA, for their helpful comments.

Marijuana, which is still illegal under federal law but legal in 30 states for medical purposes as of this writing, has shown promising results for treating peripheral neuropathy. Studies suggest that cannabis may be an option for patients whose pain responds poorly to standard treatments; however, its use may be restricted by cognitive and psychiatric adverse effects, particularly at high doses.¹

See related editorial

In this article, we discuss the basic pharmacology of cannabis and how it may affect neuropathic pain. We review clinical trials on its use for peripheral neuropathy and provide guidance for its use.

PERIPHERAL NEUROPATHY IS COMMON AND COMPLEX

An estimated 20 million people in the United States suffer from neuropathic pain. The prevalence is higher in certain populations, with 26% of people over age 65 and 30% of patients with diabetes mellitus affected.^2–4

Peripheral neuropathy is a complex, chronic state that occurs when nerve fibers are damaged, dysfunctional, or injured, sending incorrect signals to pain centers in the central nervous system.⁵ It is characterized by weakness, pain, and paresthesias that typically begin in the hands or feet and progress proximally.⁴ Symptoms depend on the number and types of nerves affected.

In many cases, peripheral neuropathy is idiopathic, but common causes include diabetes, alcoholism, human immunodeficiency virus (HIV) infection, and autoimmune disease. Others include toxicity from chemotherapy and heavy metals.

Peripheral neuropathy significantly worsens quality of life and function. Many patients experience emotional, cognitive, and functional problems, resulting in high rates of medical and psychiatric comorbidities and occupational impairment.^4,6,7 Yet despite its clinical and epidemiologic significance, it is often undertreated.⁸

STANDARD TREATMENTS INADEQUATE

Peripheral neuropathy occurs in patients with a wide range of comorbidities and is especially difficult to treat. Mainstays of therapy include anticonvulsants, tricyclic antidepressants, and serotonin-norepinephrine reuptake inhibitors.⁹ A more invasive option is spinal cord stimulation.

These treatments can have considerable adverse effects, and response rates remain suboptimal, with pain relief insufficient to improve quality of life for many patients.^9,10 Better treatments are needed to improve clinical outcomes and patient experience.¹¹

CANNABIS: A MIX OF COMPOUNDS

Cannabis sativa has been used as an analgesic for centuries. The plant contains more than 400 chemical compounds and is often used for its euphoric properties. Long-term use may lead to addiction and cognitive impairment.^12,13

Tetrahydrocannabinol (THC) and cannabidiol (CBD) are the main components and the 2 best-studied cannabinoids with analgesic effects.

THC is the primary psychoactive component of cannabis. Its effects include relaxation, altered perception, heightened sensations, increased libido, and perceptual distortions of time and space. Temporary effects may include decreased short-term memory, dry mouth, impaired motor function, conjunctival injection, paranoia, and anxiety.

CBD is nonpsychoactive and has anti-inflammatory and antioxidant properties. It has been shown to reduce pain and inflammation without the effects of THC.¹⁴

Other compounds in the cannabis plant include phytocannabinoids, flavonoids, and tapenoids, which may produce individual, interactive, or synergistic effects.¹⁵ Different strains of cannabis have varying amounts of the individual components, making comparisons among clinical studies difficult.

THE ENDOCANNABINOID SYSTEM

The endogenous mammalian cannabinoid system plays a regulatory role in the development, homeostasis, and neuroplasticity of the central nervous system. It is also involved in modulating pain transmission in the nociceptive pathway.

Two of the most abundant cannabinoid endogenous ligands are anandamide and 2-arachidonylglycerol.⁹ These endocanna­b­inoids are produced on demand in the central nervous system to reduce pain by acting as a circuit breaker.^16–18 They target the G protein-coupled cannabinoid receptors CB1 and CB2, located throughout the central and peripheral nervous system and in organs and tissues.¹²

CB1 receptors are found primarily in the central nervous system, specifically in areas involved in movement, such as the basal ganglia and cerebellum, as well as in areas involved in memory, such as the hippocampus.¹² They are also abundant in brain regions implicated in conducting and modulating pain signals, including the periaqueductal gray and the dorsal horn of the spinal cord.^16–20

CB2 receptors are mostly found in peripheral tissues and organs, mainly those involved in the immune system, including splenic, tonsillar, and hematopoietic cells.¹² They help regulate inflammation, allodynia, and hyperalgesia.¹⁷

Modifying response to injury

Following a nerve injury, neurons along the nociceptive pathway may become more reactive and responsive in a process known as sensitization.²¹ The process involves a cascade of cellular events that result in sprouting of pain-sensitive nerve endings.^21,22

Cannabinoids are thought to reduce pain by modifying these cellular events. They also inhibit nociceptive conduction in the dorsal horn of the spinal cord and in the ascending spinothalamic tract.²⁰ CB1 receptors found in nociceptive terminals along the peripheral nervous system impede pain conduction, while activation of CB2 receptors in immune cells decreases the release of nociceptive agents.

 

 

STUDIES OF CANNABIS FOR NEUROPATHIC PAIN

A number of studies have evaluated cannabis for treating neuropathic pain. Overall, available data support the efficacy of smoked or inhaled cannabis in its flower form when used as monotherapy or adjunctive therapy for relief of neuropathic pain of various etiologies. Many studies also report secondary benefits, including better sleep and functional improvement.^23,24

However, adverse effects are common, especially at high doses, and include difficulty concentrating, lightheadedness, fatigue, and tachycardia. More serious reported adverse effects include anxiety, paranoia, and psychosis.

Wilsey et al, 2008: Neuropathic pain reduced

Wilsey et al²⁵ conducted a double-blind, placebo-controlled crossover study that assessed the effects of smoking cannabis in 38 patients with central or peripheral neuropathic pain. Participants were assigned to smoke either high- or low-dose cannabis (7% or 3.5% delta-9-THC) or placebo cigarettes. Cigarettes were smoked during treatment sessions using the following regimen: 2 puffs at 60 minutes from baseline, 3 puffs at 120 minutes, and 4 puffs at 180 minutes. Patients were assessed after each set of puffs and for 2 hours afterwards. The primary outcome was spontaneous relief of pain as measured by a visual analog scale.

Pain intensity was comparable and significantly reduced in both treatment groups compared with placebo. At the high dose, some participants experienced neurocognitive impairment in attention, learning, memory, and psychomotor speed; only learning and memory declined at the low dose.

Ellis et al, 2009: Pain reduction in HIV neuropathy

Ellis et al²³ conducted a double-blind, placebo-controlled crossover trial in patients with HIV neuropathy that was unresponsive to at least 2 analgesics with different modes of action. During each treatment week, participants were randomly assigned to smoke either active cannabis or placebo, while continuing their standard therapy. Titration started at 4% THC and was adjusted based on tolerability and efficacy. Twenty-eight of the 34 enrolled patients completed both cannabis and placebo treatments. The principal outcome was change in pain intensity from baseline at the end of each week, using the Descriptor Differential Scale of Pain Intensity.

Of the 28 patients, 46% achieved an average pain reduction of 3.3 points (30%). One patient experienced cannabis-induced psychosis, and another developed an intractable cough, which resolved with smoking cessation.

Ware et al, 2010: Reduced posttraumatic or postsurgical neuropathic pain

Ware et al²⁴ performed a randomized crossover trial in 21 patients with posttraumatic or postsurgical neuropathic pain. Participants inhaled 4 different formulations of cannabis (containing 0%, 2.5%, 6.0%, and 9.4% THC) during 4 14-day periods. They inhaled a 25-mg dose through a pipe 3 times a day for the first 5 days of each cycle, followed by a 9-day washout period. Daily average pain intensity was measured using a numeric rating scale. The investigators also assessed mood, sleep, quality of life, and adverse effects.

Patients in the 9.4% THC group reported significantly less pain and better sleep, with average pain scores decreasing from 6.1 to 5.4 on an 11-point scale. Although the benefit was modest, the authors noted that the pain had been refractory to standard treatments.

The number of reported adverse events increased with greater potency and were most commonly throat irritation, burning sensation, headache, dizziness, and fatigue. This study suggests that THC potency affects tolerability, with higher doses eliciting clinically important adverse effects, some of which may reduce the ability to perform activities of daily living, such as driving.

Wilsey et al, 2013: Use in resistant neuropathic pain

Wilsey et al²⁶ conducted another double-blind, placebo-controlled crossover study assessing the effect of vaporized cannabis on central and peripheral neuropathic pain resistant to first-line pharmacotherapies. Dose-effect relationships were explored using medium-dose (3.5%), low-dose (1.3%), and placebo cannabis. The primary outcome measure was a 30% reduction in pain intensity based on a visual analog scale.

In the placebo group, 26% of patients achieved this vs 57% of the low-dose cannabis group and 61% of those receiving the medium dose. No significant difference was found between the 2 active doses in reducing neuropathic pain, and both were more effective than placebo. The number needed to treat to achieve a 30% reduction in pain was about 3 for both cannabis groups compared with placebo. Psychoactive effects were minimal, of short duration, and reversible.

Wallace et al, 2015: Use in diabetic peripheral neuropathy

Wallace et al²⁷ conducted a randomized, double-blind, placebo-controlled crossover study evaluating cannabis for diabetic peripheral neuropathy in 16 patients. Each had experienced at least 6 months of neuropathic pain in their feet. The participants inhaled a single dose of 1%, 4%, or 7% THC cannabis or placebo. Spontaneous pain was reported with a visual analog scale and also tested with a foam brush and von Frey filament at intervals until 4 hours after treatment.

Pain scores were lower with treatment compared with placebo, with high-dose cannabis having the greatest analgesic effect. Pain reduction lasted for the full duration of the test. Cannabis recipients had declines in attention and working memory, with the high-dose group experiencing the greatest impact 15 minutes after treatment. High-dose recipients also had poorer scores on testing of quick task-switching, with the greatest effect at 2 hours.²⁷

Research and market cannabis are not equal

Results of US studies must be qualified. Most have used cannabis provided by the National Institute of Drug Abuse (NIDA),^23–26 which differs in potency from commercially available preparations. This limits the clinical usefulness of the analysis of benefits and risks.

Vergara et al²⁸ found that NIDA varieties contained much lower THC levels and as much as 23 times the cannabinol content as cannabis in state-legalized markets.

Studies based on NIDA varieties likely underestimate the risks of consumer-purchased cannabis, as THC is believed to be most responsible for the risk of psychosis and impaired driving and cognition.^24,28

 

 

CBD MAY PROTECT AGAINST ADVERSE EFFECTS

Studies of CBD alone are limited to preclinical data.²⁹ Evidence suggests that CBD alone or combined with THC can suppress chronic neuropathic pain, and that CBD may have a protective effect after nerve injury.³⁰

Nabiximols, an oromucosal spray preparation with equal amounts of THC and CBD, has been approved in Canada as well as in European countries including the United Kingdom. Although its use has not been associated with many of the adverse effects of inhaled cannabis,^30–32 evidence of efficacy from clinical trials has been mixed.

Lynch et al,³¹ in a 2014 randomized, double-blind, placebo-controlled crossover pilot study³¹ evaluated nabiximols in 16 patients with neuropathic pain related to chemotherapy. No statistically significant difference was found between treatment and placebo. However, the trial was underpowered.

Serpell et al,³² in a 2014 European randomized, placebo-controlled parallel-group study, evaluated 246 patients with peripheral neuropathy with allodynia, with 128 receiving active treatment (THC-CBD oromucosal spray) and 118 receiving placebo. Over the 15-week study, participants continued their current analgesic treatments.

Pain was reduced in the treatment group, but the difference from placebo was not statistically significant. However, the treatment group reported significantly better sleep quality and Patient Global Impression of Change measures (reflecting a patient’s belief of treatment efficacy).

META-ANALYSES CONFIRM EFFECT

Three meta-analyses of available studies of the effects of cannabis on neuropathic pain have been completed.

Andreae et al, 2015: 5 trials, 178 patients

Andreae et al¹ evaluated 5 randomized controlled trials in 178 patients in North America. All had had neuropathy for at least 3 months, with a pain level of at least about 3 on a scale of 10. Two studies had patients with HIV-related neuropathy; the other 3 involved patients with neuropathy related to trauma, diabetes, complex regional pain syndrome, or spinal cord injury. All trials used whole cannabis plant provided by NIDA, and the main outcomes were patient-reported pain scales. No study evaluated pain beyond 2 weeks after trial termination.

They found that 1 of every 5 to 6 patients treated with cannabis had at least a 30% pain reduction.

Nugent et al, 2017: 13 trials, 246 patients

Nugent et al³³ reviewed 13 trials in 246 patients that evaluated the effects of different cannabis-based preparations on either central or peripheral neuropathic pain from various conditions. Actively treated patients were more likely to report a 30% improvement in neuropathic pain. Again, studies tended to be small and brief.

Cochrane review, 2018: 16 trials, 1,750 patients

A Cochrane review³⁴ analyzed 16 trials (in 1,750 patients) lasting 2 to 26 weeks. Treatments included an oromucosal spray with a plant-derived combination of THC and CBD, nabilone, inhaled herbal cannabis, and plant-derived THC.

With cannabis-based treatments, significantly more people achieved 50% or greater pain relief than with placebo (21% vs 17%, number needed to treat 20); 30% pain reduction was achieved in 39% of treated patients vs 33% of patients taking placebo (number needed to treat 11).

On the other hand, significantly more participants withdrew from studies because of adverse events with cannabis-based treatments than placebo (10% vs 5%), with psychiatric disorders occurring in 17% of patients receiving active treatment vs 5% of those receiving placebo (number needed to harm 10). 

The primary studies suffered from methodologic limitations including small size, short duration, and inconsistency of formulations and study designs. Further evaluation of long-term efficacy, tolerability, and addiction potential is critical to determine the risk-benefit ratio.

RISKS OF CANNABIS USE

Like any drug therapy, cannabis has effects that may limit its use. Cannabis can affect a person’s psyche, physiology, and lifestyle.

Impaired attention, task speed

Neurocognitive changes associated with cannabis use—especially dizziness, fatigue, and slowed task-switching—could affect driving and other complex tasks. Evidence indicates that such activities should be avoided in the hours after treatment.^26,27,32,33

Concern over brain development

Most worrisome is the effect of long-term cannabis use on brain development in young adults. Regular use of cannabis at an early age is associated with lower IQ, decline in school performance, and lower rates of high school graduation.³⁵

Avoid in psychiatric patients

It is unlikely that cannabis can be safely used in patients with psychiatric illnesses. Anxiety, depression, and psychotic disorders can be exacerbated by the regular use of cannabis, and the risk of developing these conditions is increased while using cannabis.^36,37

High concentrations of THC (the highest concentration used in the above studies was 9.5%) can cause anxiety, paranoia, and psychosis.

Respiratory effects

Long-term cannabis smoking may cause wheezing, cough, dyspnea, and exacerbations of chronic bronchitis. There is some evidence that symptoms improve after stopping smoking.^33,38

SHOULD WE RECOMMEND CANNABIS?

Where cannabis can be legally used, doctors should be familiar with the literature and its limitations so that they can counsel patients on the best use and potential risks and benefits of cannabis treatment.

A recent conceptualization of pain suggests that a pain score reflects a composite of sensory factors (eg, tissue damage), cognitive factors (eg, beliefs about pain), and affective factors (eg, anxiety, depression).³⁹ Physicians should keep this in mind when evaluating patients to better assess the risks and benefits of cannabis. While pharmacotherapy may address sensory factors, cognitive behavioral therapy may help alter beliefs about the pain as well as anxiety and depressive symptoms that might influence subjective reports.

Ideally, patients being considered for cannabis treatment would have a type of neuropathic pain proven to respond to cannabis in randomized, controlled studies, as well as evidence of failed first-line treatments.

Relative contraindications include depression, anxiety, substance use, psychotic disorders, and respiratory conditions, and these should also be considered.

Although current research shows an analgesic benefit of cannabis on neuropathic pain comparable to that of gabapentin,⁴⁰ further investigation is needed to better evaluate long-term safety, efficacy, and interactions with standard therapies. Until we have a more complete picture, we should use the current literature, along with a thorough knowledge of each patient, to determine if the benefits of cannabis therapy outweigh the risks.

Acknowledgments: We thank Camillo Ferrari, BS, and Christina McMahon, BA, for their helpful comments.

Marijuana, which is still illegal under federal law but legal in 30 states for medical purposes as of this writing, has shown promising results for treating peripheral neuropathy. Studies suggest that cannabis may be an option for patients whose pain responds poorly to standard treatments; however, its use may be restricted by cognitive and psychiatric adverse effects, particularly at high doses.¹

See related editorial

In this article, we discuss the basic pharmacology of cannabis and how it may affect neuropathic pain. We review clinical trials on its use for peripheral neuropathy and provide guidance for its use.

PERIPHERAL NEUROPATHY IS COMMON AND COMPLEX

An estimated 20 million people in the United States suffer from neuropathic pain. The prevalence is higher in certain populations, with 26% of people over age 65 and 30% of patients with diabetes mellitus affected.^2–4

Peripheral neuropathy is a complex, chronic state that occurs when nerve fibers are damaged, dysfunctional, or injured, sending incorrect signals to pain centers in the central nervous system.⁵ It is characterized by weakness, pain, and paresthesias that typically begin in the hands or feet and progress proximally.⁴ Symptoms depend on the number and types of nerves affected.

In many cases, peripheral neuropathy is idiopathic, but common causes include diabetes, alcoholism, human immunodeficiency virus (HIV) infection, and autoimmune disease. Others include toxicity from chemotherapy and heavy metals.

Peripheral neuropathy significantly worsens quality of life and function. Many patients experience emotional, cognitive, and functional problems, resulting in high rates of medical and psychiatric comorbidities and occupational impairment.^4,6,7 Yet despite its clinical and epidemiologic significance, it is often undertreated.⁸

STANDARD TREATMENTS INADEQUATE

Peripheral neuropathy occurs in patients with a wide range of comorbidities and is especially difficult to treat. Mainstays of therapy include anticonvulsants, tricyclic antidepressants, and serotonin-norepinephrine reuptake inhibitors.⁹ A more invasive option is spinal cord stimulation.

These treatments can have considerable adverse effects, and response rates remain suboptimal, with pain relief insufficient to improve quality of life for many patients.^9,10 Better treatments are needed to improve clinical outcomes and patient experience.¹¹

CANNABIS: A MIX OF COMPOUNDS

Cannabis sativa has been used as an analgesic for centuries. The plant contains more than 400 chemical compounds and is often used for its euphoric properties. Long-term use may lead to addiction and cognitive impairment.^12,13

Tetrahydrocannabinol (THC) and cannabidiol (CBD) are the main components and the 2 best-studied cannabinoids with analgesic effects.

THC is the primary psychoactive component of cannabis. Its effects include relaxation, altered perception, heightened sensations, increased libido, and perceptual distortions of time and space. Temporary effects may include decreased short-term memory, dry mouth, impaired motor function, conjunctival injection, paranoia, and anxiety.

CBD is nonpsychoactive and has anti-inflammatory and antioxidant properties. It has been shown to reduce pain and inflammation without the effects of THC.¹⁴

Other compounds in the cannabis plant include phytocannabinoids, flavonoids, and tapenoids, which may produce individual, interactive, or synergistic effects.¹⁵ Different strains of cannabis have varying amounts of the individual components, making comparisons among clinical studies difficult.

THE ENDOCANNABINOID SYSTEM

The endogenous mammalian cannabinoid system plays a regulatory role in the development, homeostasis, and neuroplasticity of the central nervous system. It is also involved in modulating pain transmission in the nociceptive pathway.

Two of the most abundant cannabinoid endogenous ligands are anandamide and 2-arachidonylglycerol.⁹ These endocanna­b­inoids are produced on demand in the central nervous system to reduce pain by acting as a circuit breaker.^16–18 They target the G protein-coupled cannabinoid receptors CB1 and CB2, located throughout the central and peripheral nervous system and in organs and tissues.¹²

CB1 receptors are found primarily in the central nervous system, specifically in areas involved in movement, such as the basal ganglia and cerebellum, as well as in areas involved in memory, such as the hippocampus.¹² They are also abundant in brain regions implicated in conducting and modulating pain signals, including the periaqueductal gray and the dorsal horn of the spinal cord.^16–20

CB2 receptors are mostly found in peripheral tissues and organs, mainly those involved in the immune system, including splenic, tonsillar, and hematopoietic cells.¹² They help regulate inflammation, allodynia, and hyperalgesia.¹⁷

Modifying response to injury

Following a nerve injury, neurons along the nociceptive pathway may become more reactive and responsive in a process known as sensitization.²¹ The process involves a cascade of cellular events that result in sprouting of pain-sensitive nerve endings.^21,22

Cannabinoids are thought to reduce pain by modifying these cellular events. They also inhibit nociceptive conduction in the dorsal horn of the spinal cord and in the ascending spinothalamic tract.²⁰ CB1 receptors found in nociceptive terminals along the peripheral nervous system impede pain conduction, while activation of CB2 receptors in immune cells decreases the release of nociceptive agents.

 

 

STUDIES OF CANNABIS FOR NEUROPATHIC PAIN

A number of studies have evaluated cannabis for treating neuropathic pain. Overall, available data support the efficacy of smoked or inhaled cannabis in its flower form when used as monotherapy or adjunctive therapy for relief of neuropathic pain of various etiologies. Many studies also report secondary benefits, including better sleep and functional improvement.^23,24

However, adverse effects are common, especially at high doses, and include difficulty concentrating, lightheadedness, fatigue, and tachycardia. More serious reported adverse effects include anxiety, paranoia, and psychosis.

Wilsey et al, 2008: Neuropathic pain reduced

Wilsey et al²⁵ conducted a double-blind, placebo-controlled crossover study that assessed the effects of smoking cannabis in 38 patients with central or peripheral neuropathic pain. Participants were assigned to smoke either high- or low-dose cannabis (7% or 3.5% delta-9-THC) or placebo cigarettes. Cigarettes were smoked during treatment sessions using the following regimen: 2 puffs at 60 minutes from baseline, 3 puffs at 120 minutes, and 4 puffs at 180 minutes. Patients were assessed after each set of puffs and for 2 hours afterwards. The primary outcome was spontaneous relief of pain as measured by a visual analog scale.

Pain intensity was comparable and significantly reduced in both treatment groups compared with placebo. At the high dose, some participants experienced neurocognitive impairment in attention, learning, memory, and psychomotor speed; only learning and memory declined at the low dose.

Ellis et al, 2009: Pain reduction in HIV neuropathy

Ellis et al²³ conducted a double-blind, placebo-controlled crossover trial in patients with HIV neuropathy that was unresponsive to at least 2 analgesics with different modes of action. During each treatment week, participants were randomly assigned to smoke either active cannabis or placebo, while continuing their standard therapy. Titration started at 4% THC and was adjusted based on tolerability and efficacy. Twenty-eight of the 34 enrolled patients completed both cannabis and placebo treatments. The principal outcome was change in pain intensity from baseline at the end of each week, using the Descriptor Differential Scale of Pain Intensity.

Of the 28 patients, 46% achieved an average pain reduction of 3.3 points (30%). One patient experienced cannabis-induced psychosis, and another developed an intractable cough, which resolved with smoking cessation.

Ware et al, 2010: Reduced posttraumatic or postsurgical neuropathic pain

Ware et al²⁴ performed a randomized crossover trial in 21 patients with posttraumatic or postsurgical neuropathic pain. Participants inhaled 4 different formulations of cannabis (containing 0%, 2.5%, 6.0%, and 9.4% THC) during 4 14-day periods. They inhaled a 25-mg dose through a pipe 3 times a day for the first 5 days of each cycle, followed by a 9-day washout period. Daily average pain intensity was measured using a numeric rating scale. The investigators also assessed mood, sleep, quality of life, and adverse effects.

Patients in the 9.4% THC group reported significantly less pain and better sleep, with average pain scores decreasing from 6.1 to 5.4 on an 11-point scale. Although the benefit was modest, the authors noted that the pain had been refractory to standard treatments.

The number of reported adverse events increased with greater potency and were most commonly throat irritation, burning sensation, headache, dizziness, and fatigue. This study suggests that THC potency affects tolerability, with higher doses eliciting clinically important adverse effects, some of which may reduce the ability to perform activities of daily living, such as driving.

Wilsey et al, 2013: Use in resistant neuropathic pain

Wilsey et al²⁶ conducted another double-blind, placebo-controlled crossover study assessing the effect of vaporized cannabis on central and peripheral neuropathic pain resistant to first-line pharmacotherapies. Dose-effect relationships were explored using medium-dose (3.5%), low-dose (1.3%), and placebo cannabis. The primary outcome measure was a 30% reduction in pain intensity based on a visual analog scale.

In the placebo group, 26% of patients achieved this vs 57% of the low-dose cannabis group and 61% of those receiving the medium dose. No significant difference was found between the 2 active doses in reducing neuropathic pain, and both were more effective than placebo. The number needed to treat to achieve a 30% reduction in pain was about 3 for both cannabis groups compared with placebo. Psychoactive effects were minimal, of short duration, and reversible.

Wallace et al, 2015: Use in diabetic peripheral neuropathy

Wallace et al²⁷ conducted a randomized, double-blind, placebo-controlled crossover study evaluating cannabis for diabetic peripheral neuropathy in 16 patients. Each had experienced at least 6 months of neuropathic pain in their feet. The participants inhaled a single dose of 1%, 4%, or 7% THC cannabis or placebo. Spontaneous pain was reported with a visual analog scale and also tested with a foam brush and von Frey filament at intervals until 4 hours after treatment.

Pain scores were lower with treatment compared with placebo, with high-dose cannabis having the greatest analgesic effect. Pain reduction lasted for the full duration of the test. Cannabis recipients had declines in attention and working memory, with the high-dose group experiencing the greatest impact 15 minutes after treatment. High-dose recipients also had poorer scores on testing of quick task-switching, with the greatest effect at 2 hours.²⁷

Research and market cannabis are not equal

Results of US studies must be qualified. Most have used cannabis provided by the National Institute of Drug Abuse (NIDA),^23–26 which differs in potency from commercially available preparations. This limits the clinical usefulness of the analysis of benefits and risks.

Vergara et al²⁸ found that NIDA varieties contained much lower THC levels and as much as 23 times the cannabinol content as cannabis in state-legalized markets.

Studies based on NIDA varieties likely underestimate the risks of consumer-purchased cannabis, as THC is believed to be most responsible for the risk of psychosis and impaired driving and cognition.^24,28

 

 

CBD MAY PROTECT AGAINST ADVERSE EFFECTS

Studies of CBD alone are limited to preclinical data.²⁹ Evidence suggests that CBD alone or combined with THC can suppress chronic neuropathic pain, and that CBD may have a protective effect after nerve injury.³⁰

Nabiximols, an oromucosal spray preparation with equal amounts of THC and CBD, has been approved in Canada as well as in European countries including the United Kingdom. Although its use has not been associated with many of the adverse effects of inhaled cannabis,^30–32 evidence of efficacy from clinical trials has been mixed.

Lynch et al,³¹ in a 2014 randomized, double-blind, placebo-controlled crossover pilot study³¹ evaluated nabiximols in 16 patients with neuropathic pain related to chemotherapy. No statistically significant difference was found between treatment and placebo. However, the trial was underpowered.

Serpell et al,³² in a 2014 European randomized, placebo-controlled parallel-group study, evaluated 246 patients with peripheral neuropathy with allodynia, with 128 receiving active treatment (THC-CBD oromucosal spray) and 118 receiving placebo. Over the 15-week study, participants continued their current analgesic treatments.

Pain was reduced in the treatment group, but the difference from placebo was not statistically significant. However, the treatment group reported significantly better sleep quality and Patient Global Impression of Change measures (reflecting a patient’s belief of treatment efficacy).

META-ANALYSES CONFIRM EFFECT

Three meta-analyses of available studies of the effects of cannabis on neuropathic pain have been completed.

Andreae et al, 2015: 5 trials, 178 patients

Andreae et al¹ evaluated 5 randomized controlled trials in 178 patients in North America. All had had neuropathy for at least 3 months, with a pain level of at least about 3 on a scale of 10. Two studies had patients with HIV-related neuropathy; the other 3 involved patients with neuropathy related to trauma, diabetes, complex regional pain syndrome, or spinal cord injury. All trials used whole cannabis plant provided by NIDA, and the main outcomes were patient-reported pain scales. No study evaluated pain beyond 2 weeks after trial termination.

They found that 1 of every 5 to 6 patients treated with cannabis had at least a 30% pain reduction.

Nugent et al, 2017: 13 trials, 246 patients

Nugent et al³³ reviewed 13 trials in 246 patients that evaluated the effects of different cannabis-based preparations on either central or peripheral neuropathic pain from various conditions. Actively treated patients were more likely to report a 30% improvement in neuropathic pain. Again, studies tended to be small and brief.

Cochrane review, 2018: 16 trials, 1,750 patients

A Cochrane review³⁴ analyzed 16 trials (in 1,750 patients) lasting 2 to 26 weeks. Treatments included an oromucosal spray with a plant-derived combination of THC and CBD, nabilone, inhaled herbal cannabis, and plant-derived THC.

With cannabis-based treatments, significantly more people achieved 50% or greater pain relief than with placebo (21% vs 17%, number needed to treat 20); 30% pain reduction was achieved in 39% of treated patients vs 33% of patients taking placebo (number needed to treat 11).

On the other hand, significantly more participants withdrew from studies because of adverse events with cannabis-based treatments than placebo (10% vs 5%), with psychiatric disorders occurring in 17% of patients receiving active treatment vs 5% of those receiving placebo (number needed to harm 10). 

The primary studies suffered from methodologic limitations including small size, short duration, and inconsistency of formulations and study designs. Further evaluation of long-term efficacy, tolerability, and addiction potential is critical to determine the risk-benefit ratio.

RISKS OF CANNABIS USE

Like any drug therapy, cannabis has effects that may limit its use. Cannabis can affect a person’s psyche, physiology, and lifestyle.

Impaired attention, task speed

Neurocognitive changes associated with cannabis use—especially dizziness, fatigue, and slowed task-switching—could affect driving and other complex tasks. Evidence indicates that such activities should be avoided in the hours after treatment.^26,27,32,33

Concern over brain development

Most worrisome is the effect of long-term cannabis use on brain development in young adults. Regular use of cannabis at an early age is associated with lower IQ, decline in school performance, and lower rates of high school graduation.³⁵

Avoid in psychiatric patients

It is unlikely that cannabis can be safely used in patients with psychiatric illnesses. Anxiety, depression, and psychotic disorders can be exacerbated by the regular use of cannabis, and the risk of developing these conditions is increased while using cannabis.^36,37

High concentrations of THC (the highest concentration used in the above studies was 9.5%) can cause anxiety, paranoia, and psychosis.

Respiratory effects

Long-term cannabis smoking may cause wheezing, cough, dyspnea, and exacerbations of chronic bronchitis. There is some evidence that symptoms improve after stopping smoking.^33,38

SHOULD WE RECOMMEND CANNABIS?

Where cannabis can be legally used, doctors should be familiar with the literature and its limitations so that they can counsel patients on the best use and potential risks and benefits of cannabis treatment.

A recent conceptualization of pain suggests that a pain score reflects a composite of sensory factors (eg, tissue damage), cognitive factors (eg, beliefs about pain), and affective factors (eg, anxiety, depression).³⁹ Physicians should keep this in mind when evaluating patients to better assess the risks and benefits of cannabis. While pharmacotherapy may address sensory factors, cognitive behavioral therapy may help alter beliefs about the pain as well as anxiety and depressive symptoms that might influence subjective reports.

Ideally, patients being considered for cannabis treatment would have a type of neuropathic pain proven to respond to cannabis in randomized, controlled studies, as well as evidence of failed first-line treatments.

Relative contraindications include depression, anxiety, substance use, psychotic disorders, and respiratory conditions, and these should also be considered.

Although current research shows an analgesic benefit of cannabis on neuropathic pain comparable to that of gabapentin,⁴⁰ further investigation is needed to better evaluate long-term safety, efficacy, and interactions with standard therapies. Until we have a more complete picture, we should use the current literature, along with a thorough knowledge of each patient, to determine if the benefits of cannabis therapy outweigh the risks.

Acknowledgments: We thank Camillo Ferrari, BS, and Christina McMahon, BA, for their helpful comments.

Unfortunately, recent research has not unveiled a breakthrough for preventing or treating cognitive impairment or Alzheimer disease. But several studies from the last 2 years are helping to drive the field of geriatrics forward, providing evidence of what does and does not help a variety of issues specific to the elderly. 

Based on a search of the 2017 and 2018 literature, this article presents new evidence on preventing and treating cognitive impairment, managing dementia-associated behavioral disturbances and delirium, preventing falls, and improving inpatient mobility and posthospital care transitions.

COGNITIVE IMPAIRMENT, DEMENTIA: STILL NO SILVER BULLET

With the exception of oral anticoagulation treatment for atrial fibrillation, there is little evidence that pharmacologic or nonpharmacologic interventions slow the onset or progression of Alzheimer disease.

Nonpharmacologic interventions

Home occupational therapy. A 2-year home-based occupational therapy intervention¹ showed no evidence of slowing functional decline in patients with Alzheimer disease. The randomized controlled trial involving 180 participants consisted of monthly sessions of an intensive, well-established collaborative-care management model that included fall prevention and other safety strategies, personalized training in activities of daily living, exercise, and education. Outcome measures for activities of daily living did not differ significantly between the treatment and control groups.¹

Physical activity. Whether physical activity interventions slow cognitive decline and prevent dementia in cognitively intact adults was examined in a systematic review of 32 trials.² Most of the trials followed patients for 6 months; a few stretched for 1 or 2 years.

Evidence was insufficient to prove cognitive benefit for short-term, single-component or multicomponent physical activity interventions. However, a multidomain physical activity intervention that also included dietary modifications and cognitive training did show a delay in cognitive decline, but only “low-strength” evidence.²

Nutritional supplements. The antioxidants vitamin E and selenium were studied for their possible cognitive benefit in the double-blind randomized Prevention of Alzheimer Disease by Vitamin E and Selenium trial³ in 3,786 asymptomatic men ages 60 and older. Neither supplement was found to prevent dementia over a 7-year follow-up period.

A review of 38 trials⁴ evaluated the effects on cognition of omega-3 fatty acids, soy, ginkgo biloba, B vitamins, vitamin D plus calcium, vitamin C, beta-carotene, and multi-ingredient supplements. It found insufficient evidence to recommend any over-the-counter supplement for cognitive protection in adults with normal cognition or mild cognitive impairment.

Pharmacologic treatments

Testosterone supplementation. The Testosterone Trials tested the effects of testosterone gel vs placebo for 1 year on 493 men over age 65 with low testosterone (< 275 ng/mL) and with subjective memory complaints and objective memory performance deficits. Treatment was not associated with improved memory or other cognitive functions compared with placebo.⁵

Antiamyloid drugs. A randomized, double-blind, placebo-controlled trial in nearly 2,000 patients evaluated verubecestat, an oral beta-site amyloid precursor protein-cleaving enzyme-1 inhibitor that reduces the amyloid-beta level in cerebrospinal fluid.⁶

Verubecestat did not reduce cognitive or functional decline in patients with mild-to-moderate Alzheimer disease, while adverse events including rashes, falls, injuries, sleep disturbances, suicidal ideation, weight loss, and hair color change were more common in the treatment groups. The trial was terminated early because of futility at 50 months.

And in a placebo-controlled trial of solanezumab, a monoclonal antibody directed against the amyloid beta peptide, no benefit was demonstrated at 80 weeks in more than 2,000 patients with Alzheimer disease.⁷

Multiple common agents. A well-conducted systematic review⁸ of 51 trials of at least a 6-month duration did not support the use of antihypertensive agents, diabetes medications, nonsteroidal anti-inflammatory drugs, aspirin, hormones, or lipid-lowering drugs for cognitive protection for people with normal cognition or mild cognitive impairment.

However, some studies found reassuring evidence that standard therapies for other conditions do not worsen cognitive decline and are protective for atrial fibrillation.⁸

Proton-pump inhibitors. Concern exists for a potential link between dementia risk and proton-pump inhibitors, which are widely used to treat acid-related gastrointestinal disorders.⁹

A prospective population-based cohort study¹⁰ of nearly 3,500 people ages 65 and older without baseline dementia screened participants for dementia every 2 years over a mean period of 7.5 years and provided further evaluation for those who screened positive. Use of proton-pump inhibitors was not found to be associated with dementia risk, even with high cumulative exposure.

Results from this study do not support avoiding proton-pump inhibitors out of concern for dementia risk, although long-term use is associated with other safety concerns.

Oral anticoagulation. The increased risk of dementia with atrial fibrillation is well documented.¹¹

A retrospective study¹² based on a Swedish health registry and using more than 444,000 patients covering more than 1.5 million years at risk found that oral anticoagulant treatment at baseline conferred a 29% lower risk of dementia in an intention-to-treat analysis and a 48% lower risk in on-treatment analysis compared with no oral anticoagulation therapy. No difference was found between new oral anticoagulants and warfarin.

Transcatheter aortic valve implantation is not associated with cognitive decline

For patients with severe aortic stenosis who are not surgical candidates, transcatheter aortic valve implantation is superior to standard medical therapy,¹³ but there are concerns of neurologic and cognitive changes after the procedure.¹⁴ A meta-analysis of 18 studies assessing cognitive performance in more than 1,000 patients (average age ≥ 80) after undergoing the procedure for severe aortic stenosis found no significant cognitive performance changes from baseline perioperatively or 3 or 6 months later.¹⁵

 

 

TREATING DEMENTIA-ASSOCIATED BEHAVIORAL DISTURBANCES

Behavioral and psychiatric symptoms often accompany dementia, but no drugs have yet been approved by the US Food and Drug Administration (FDA) to address them in this population. Nonpharmacologic interventions are recommended as first-line therapy.

Antipsychotics are not recommended

Antipsychotics are often prescribed,¹⁶ although they are associated with metabolic syndrome¹⁷ and increased risks of stroke and death.¹⁸ The FDA has issued black box warnings against using antipsychotics for behavioral management in patients with dementia. Further, the American Geriatrics Society and the American Psychiatric Association do not endorse using them as initial therapy for behavioral and psychological symptoms of dementia.^16,19

The Centers for Medicare and Medicaid Services partnered with nursing homes to improve the quality of care for patients with dementia, with results measured as the rate of prescribing antipsychotic medications. Although the use of psychotropic medications declined after initiating the partnership, the use of mood stabilizers increased, possibly as a substitute for antipsychotics.²⁰

Dextromethorphan-quinidine use is up, despite modest evidence of benefit

A consumer news report in 2017 stated that the use of dextromethorphan-quinidine in long-term care facilities increased by nearly 400% between 2012 and 2016.²¹

Evidence for its benefits comes from a 10-week, phase 2, randomized controlled trial conducted at 42 US study sites with 194 patients with probable Alzheimer disease. Compared with the placebo group, the active treatment group had mildly reduced agitation but an increased risk of falls, dizziness, and diarrhea. However, rates of adverse effects were low, and the authors concluded that treatment was generally well tolerated.²²

Pimavanserin: No long-term benefit for psychosis

In a phase 2, randomized, double-blind, placebo-controlled trial in 181 patients with possible or probable Alzheimer disease and psychotic symptoms, pimavanserin was associated with improved symptoms as measured by the Neuropsychiatric Inventory–Nursing Home Version psychosis score at 6 weeks, but no difference was found compared with placebo at 12 weeks. The treatment group had more adverse events, including agitation, aggression, peripheral edema, anxiety, and symptoms of dementia, although the differences were not statistically significant.²³               

DELIRIUM: AVOID ANTIPSYCHOTICS

Delirium is common in hospitalized older adults, especially those who have baseline cognitive or functional impairment and are exposed to precipitating factors such as treatment with anticholinergic or narcotic medications, infection, surgery, or admission to an intensive care unit.²⁴

Delirium at discharge predicts poor outcomes

In a prospective study of 152 hospitalized patients with delirium, those who either did not recover from delirium or had only partially recovered at discharge were more likely to visit the emergency department, be rehospitalized, or die during the subsequent 3 months than those who had fully recovered from delirium at discharge.²⁵

Multicomponent, patient-centered approach can help

A randomized trial in 377 patients in Taiwan evaluated the use of a modified Hospital Elder Life Program, consisting of 3 protocols focused on orienting communication, oral and nutritional assistance, and early mobilization. Patients were at least 65 years old and undergoing elective abdominal surgery with expected length of hospital stay longer than 6 days. The program, administered daily during hospitalization, significantly lowered postoperative delirium by 56% and hospital stay by 2 days compared with usual care.²⁶

Prophylactic haloperidol does not improve outcomes

In a multicenter randomized, double-blind, placebo-controlled trial, van den Boogaard et al studied prophylactic intravenous haloperidol in nearly 1,800 critically ill patients at high risk of delirium.²⁷ Haloperidol did not improve survival at 28 days compared with placebo. For secondary outcomes, including delirium incidence, delirium-free and coma-free days, duration of mechanical ventilation, and hospital and intensive care department length of stay, treatment was not found to differ statistically from placebo.

Antipsychotics may worsen delirium

A double-blind, parallel-arm, dose-titrated randomized trial, conducted at 11 Australian hospices or hospitals with palliative care services, administered oral risperidone, haloperidol, or placebo to 247 patients with life-limiting illness and delirium. Both treatment groups had higher delirium symptom scores than the placebo group.²⁸

In addition, a systematic review and meta-analysis of 19 studies found no benefit of antipsychotic medications for preventing or treating delirium in hospitalized adults.²⁹

Antipsychotics are often continued indefinitely

A retrospective chart review at a US academic health system found³⁰ that among 487 patients with a new antipsychotic medication prescribed during hospitalization, 147 (30.2%) were discharged on an antipsychotic. Of these, 121 (82.3%) had a diagnosis of delirium. Only 15 (12.4%) had discharge summaries that included instructions for discontinuing the drug.

Another US health system retrospectively reviewed antipsychotic use and found³¹ that out of 260 patients who were newly exposed to an antipsychotic drug during hospitalization, 146 (56.2%) were discharged on an antipsychotic drug, and 65% of these patients were still on the drug at the time of the next hospital admission.

 

 

EXERCISE, EXERCISE, EXERCISE

Exercise recommended, but not vitamin D, to prevent falls

In 2018, the US Preventive Services Task Force updated its recommendations for preventing falls in community-dwelling older adults.³² Based on the findings of several trials, the task force recommends exercise interventions for adults age 65 and older who are at increased risk for falls. Gait, balance, and functional training were studied in 17 trials, resistance training in 13, flexibility in 8, endurance training in 5, and tai chi in 3, with 5 studies including general physical activity. Exercise interventions most commonly took place for 3 sessions per week for 12 months (range 2–42 months).

The task force also recommends against vitamin D supplementation for fall prevention in community-dwelling adults age 65 or older who are not known to have osteoporosis or vitamin D deficiency.

Early mobilization helps inpatients

Hospitalized older adults usually spend most of their time in bed. Forty-five previously ambulatory patients (age ≥ 65 without dementia or delirium) in a Veterans Affairs hospital were monitored with wireless accelerometers and were found to spend, on average, 83% of the measured hospital stay in bed. Standing or walking time ranged from 0.2% to 21%, with a median of only 3% (43 minutes a day).³³

Since falls with injury became a Centers for Medicare and Medicaid Services nonreimbursable hospital-acquired condition, tension has arisen between promoting mobility and preventing falls.³⁴ Two studies evaluating the adoption of mobility-restricting approaches such as bed-alarms, “fall-alert” signs, supervision of patients in the bathroom, and ensuring patients’ walking aids are within reach, did not find a significant reduction in falls or fall-related injuries.^35,36

A clinically significant loss of community mobility is common after hospitalization in older adults.³⁷ Older adults who developed mobility impairment during hospitalization had a higher risk of death in a large, retrospective study.³⁸ A large Canadian multisite intervention trial³⁹ that promoted early mobilization in older patients who were admitted to general medical wards resulted in increased mobilization and significantly shorter hospital stays.

POSTHOSPITAL CARE NEEDS IMPROVEMENT

After hospitalization, older adults who have difficulty with activities of daily living or complex medical needs often require continued care.

About 20% of hospitalized Medicare beneficiaries in the United States are discharged to skilled nursing facilities.⁴⁰ This is often a stressful transition, and most people have little guidance on selecting a facility and simply choose one based on its proximity to home.⁴¹

A program of frequent visits by hospital-employed physicians and advanced practice professionals at skilled nursing facilities resulted in a significantly lower 30-day readmission rate compared with nonparticipating skilled nursing facilities in the same geographic area.⁴²

Home healthcare is recommended after hospital discharge at a rapidly increasing rate. Overall referral rates increased from 8.6% to 14.1% between 2001 and 2012, and from 14.3% to 24.0% for patients with heart failure.⁴³ A qualitative study of home healthcare nurses found a need for improved care coordination between home healthcare agencies and discharging hospitals, including defining accountability for orders and enhancing communication.⁴⁴

Unfortunately, recent research has not unveiled a breakthrough for preventing or treating cognitive impairment or Alzheimer disease. But several studies from the last 2 years are helping to drive the field of geriatrics forward, providing evidence of what does and does not help a variety of issues specific to the elderly. 

Based on a search of the 2017 and 2018 literature, this article presents new evidence on preventing and treating cognitive impairment, managing dementia-associated behavioral disturbances and delirium, preventing falls, and improving inpatient mobility and posthospital care transitions.

COGNITIVE IMPAIRMENT, DEMENTIA: STILL NO SILVER BULLET

With the exception of oral anticoagulation treatment for atrial fibrillation, there is little evidence that pharmacologic or nonpharmacologic interventions slow the onset or progression of Alzheimer disease.

Nonpharmacologic interventions

Home occupational therapy. A 2-year home-based occupational therapy intervention¹ showed no evidence of slowing functional decline in patients with Alzheimer disease. The randomized controlled trial involving 180 participants consisted of monthly sessions of an intensive, well-established collaborative-care management model that included fall prevention and other safety strategies, personalized training in activities of daily living, exercise, and education. Outcome measures for activities of daily living did not differ significantly between the treatment and control groups.¹

Physical activity. Whether physical activity interventions slow cognitive decline and prevent dementia in cognitively intact adults was examined in a systematic review of 32 trials.² Most of the trials followed patients for 6 months; a few stretched for 1 or 2 years.

Evidence was insufficient to prove cognitive benefit for short-term, single-component or multicomponent physical activity interventions. However, a multidomain physical activity intervention that also included dietary modifications and cognitive training did show a delay in cognitive decline, but only “low-strength” evidence.²

Nutritional supplements. The antioxidants vitamin E and selenium were studied for their possible cognitive benefit in the double-blind randomized Prevention of Alzheimer Disease by Vitamin E and Selenium trial³ in 3,786 asymptomatic men ages 60 and older. Neither supplement was found to prevent dementia over a 7-year follow-up period.

A review of 38 trials⁴ evaluated the effects on cognition of omega-3 fatty acids, soy, ginkgo biloba, B vitamins, vitamin D plus calcium, vitamin C, beta-carotene, and multi-ingredient supplements. It found insufficient evidence to recommend any over-the-counter supplement for cognitive protection in adults with normal cognition or mild cognitive impairment.

Pharmacologic treatments

Testosterone supplementation. The Testosterone Trials tested the effects of testosterone gel vs placebo for 1 year on 493 men over age 65 with low testosterone (< 275 ng/mL) and with subjective memory complaints and objective memory performance deficits. Treatment was not associated with improved memory or other cognitive functions compared with placebo.⁵

Antiamyloid drugs. A randomized, double-blind, placebo-controlled trial in nearly 2,000 patients evaluated verubecestat, an oral beta-site amyloid precursor protein-cleaving enzyme-1 inhibitor that reduces the amyloid-beta level in cerebrospinal fluid.⁶

Verubecestat did not reduce cognitive or functional decline in patients with mild-to-moderate Alzheimer disease, while adverse events including rashes, falls, injuries, sleep disturbances, suicidal ideation, weight loss, and hair color change were more common in the treatment groups. The trial was terminated early because of futility at 50 months.

And in a placebo-controlled trial of solanezumab, a monoclonal antibody directed against the amyloid beta peptide, no benefit was demonstrated at 80 weeks in more than 2,000 patients with Alzheimer disease.⁷

Multiple common agents. A well-conducted systematic review⁸ of 51 trials of at least a 6-month duration did not support the use of antihypertensive agents, diabetes medications, nonsteroidal anti-inflammatory drugs, aspirin, hormones, or lipid-lowering drugs for cognitive protection for people with normal cognition or mild cognitive impairment.

However, some studies found reassuring evidence that standard therapies for other conditions do not worsen cognitive decline and are protective for atrial fibrillation.⁸

Proton-pump inhibitors. Concern exists for a potential link between dementia risk and proton-pump inhibitors, which are widely used to treat acid-related gastrointestinal disorders.⁹

A prospective population-based cohort study¹⁰ of nearly 3,500 people ages 65 and older without baseline dementia screened participants for dementia every 2 years over a mean period of 7.5 years and provided further evaluation for those who screened positive. Use of proton-pump inhibitors was not found to be associated with dementia risk, even with high cumulative exposure.

Results from this study do not support avoiding proton-pump inhibitors out of concern for dementia risk, although long-term use is associated with other safety concerns.

Oral anticoagulation. The increased risk of dementia with atrial fibrillation is well documented.¹¹

A retrospective study¹² based on a Swedish health registry and using more than 444,000 patients covering more than 1.5 million years at risk found that oral anticoagulant treatment at baseline conferred a 29% lower risk of dementia in an intention-to-treat analysis and a 48% lower risk in on-treatment analysis compared with no oral anticoagulation therapy. No difference was found between new oral anticoagulants and warfarin.

Transcatheter aortic valve implantation is not associated with cognitive decline

For patients with severe aortic stenosis who are not surgical candidates, transcatheter aortic valve implantation is superior to standard medical therapy,¹³ but there are concerns of neurologic and cognitive changes after the procedure.¹⁴ A meta-analysis of 18 studies assessing cognitive performance in more than 1,000 patients (average age ≥ 80) after undergoing the procedure for severe aortic stenosis found no significant cognitive performance changes from baseline perioperatively or 3 or 6 months later.¹⁵

 

 

TREATING DEMENTIA-ASSOCIATED BEHAVIORAL DISTURBANCES

Behavioral and psychiatric symptoms often accompany dementia, but no drugs have yet been approved by the US Food and Drug Administration (FDA) to address them in this population. Nonpharmacologic interventions are recommended as first-line therapy.

Antipsychotics are not recommended

Antipsychotics are often prescribed,¹⁶ although they are associated with metabolic syndrome¹⁷ and increased risks of stroke and death.¹⁸ The FDA has issued black box warnings against using antipsychotics for behavioral management in patients with dementia. Further, the American Geriatrics Society and the American Psychiatric Association do not endorse using them as initial therapy for behavioral and psychological symptoms of dementia.^16,19

The Centers for Medicare and Medicaid Services partnered with nursing homes to improve the quality of care for patients with dementia, with results measured as the rate of prescribing antipsychotic medications. Although the use of psychotropic medications declined after initiating the partnership, the use of mood stabilizers increased, possibly as a substitute for antipsychotics.²⁰

Dextromethorphan-quinidine use is up, despite modest evidence of benefit

A consumer news report in 2017 stated that the use of dextromethorphan-quinidine in long-term care facilities increased by nearly 400% between 2012 and 2016.²¹

Evidence for its benefits comes from a 10-week, phase 2, randomized controlled trial conducted at 42 US study sites with 194 patients with probable Alzheimer disease. Compared with the placebo group, the active treatment group had mildly reduced agitation but an increased risk of falls, dizziness, and diarrhea. However, rates of adverse effects were low, and the authors concluded that treatment was generally well tolerated.²²

Pimavanserin: No long-term benefit for psychosis

In a phase 2, randomized, double-blind, placebo-controlled trial in 181 patients with possible or probable Alzheimer disease and psychotic symptoms, pimavanserin was associated with improved symptoms as measured by the Neuropsychiatric Inventory–Nursing Home Version psychosis score at 6 weeks, but no difference was found compared with placebo at 12 weeks. The treatment group had more adverse events, including agitation, aggression, peripheral edema, anxiety, and symptoms of dementia, although the differences were not statistically significant.²³               

DELIRIUM: AVOID ANTIPSYCHOTICS

Delirium is common in hospitalized older adults, especially those who have baseline cognitive or functional impairment and are exposed to precipitating factors such as treatment with anticholinergic or narcotic medications, infection, surgery, or admission to an intensive care unit.²⁴

Delirium at discharge predicts poor outcomes

In a prospective study of 152 hospitalized patients with delirium, those who either did not recover from delirium or had only partially recovered at discharge were more likely to visit the emergency department, be rehospitalized, or die during the subsequent 3 months than those who had fully recovered from delirium at discharge.²⁵

Multicomponent, patient-centered approach can help

A randomized trial in 377 patients in Taiwan evaluated the use of a modified Hospital Elder Life Program, consisting of 3 protocols focused on orienting communication, oral and nutritional assistance, and early mobilization. Patients were at least 65 years old and undergoing elective abdominal surgery with expected length of hospital stay longer than 6 days. The program, administered daily during hospitalization, significantly lowered postoperative delirium by 56% and hospital stay by 2 days compared with usual care.²⁶

Prophylactic haloperidol does not improve outcomes

In a multicenter randomized, double-blind, placebo-controlled trial, van den Boogaard et al studied prophylactic intravenous haloperidol in nearly 1,800 critically ill patients at high risk of delirium.²⁷ Haloperidol did not improve survival at 28 days compared with placebo. For secondary outcomes, including delirium incidence, delirium-free and coma-free days, duration of mechanical ventilation, and hospital and intensive care department length of stay, treatment was not found to differ statistically from placebo.

Antipsychotics may worsen delirium

A double-blind, parallel-arm, dose-titrated randomized trial, conducted at 11 Australian hospices or hospitals with palliative care services, administered oral risperidone, haloperidol, or placebo to 247 patients with life-limiting illness and delirium. Both treatment groups had higher delirium symptom scores than the placebo group.²⁸

In addition, a systematic review and meta-analysis of 19 studies found no benefit of antipsychotic medications for preventing or treating delirium in hospitalized adults.²⁹

Antipsychotics are often continued indefinitely

A retrospective chart review at a US academic health system found³⁰ that among 487 patients with a new antipsychotic medication prescribed during hospitalization, 147 (30.2%) were discharged on an antipsychotic. Of these, 121 (82.3%) had a diagnosis of delirium. Only 15 (12.4%) had discharge summaries that included instructions for discontinuing the drug.

Another US health system retrospectively reviewed antipsychotic use and found³¹ that out of 260 patients who were newly exposed to an antipsychotic drug during hospitalization, 146 (56.2%) were discharged on an antipsychotic drug, and 65% of these patients were still on the drug at the time of the next hospital admission.

 

 

EXERCISE, EXERCISE, EXERCISE

Exercise recommended, but not vitamin D, to prevent falls

In 2018, the US Preventive Services Task Force updated its recommendations for preventing falls in community-dwelling older adults.³² Based on the findings of several trials, the task force recommends exercise interventions for adults age 65 and older who are at increased risk for falls. Gait, balance, and functional training were studied in 17 trials, resistance training in 13, flexibility in 8, endurance training in 5, and tai chi in 3, with 5 studies including general physical activity. Exercise interventions most commonly took place for 3 sessions per week for 12 months (range 2–42 months).

The task force also recommends against vitamin D supplementation for fall prevention in community-dwelling adults age 65 or older who are not known to have osteoporosis or vitamin D deficiency.

Early mobilization helps inpatients

Hospitalized older adults usually spend most of their time in bed. Forty-five previously ambulatory patients (age ≥ 65 without dementia or delirium) in a Veterans Affairs hospital were monitored with wireless accelerometers and were found to spend, on average, 83% of the measured hospital stay in bed. Standing or walking time ranged from 0.2% to 21%, with a median of only 3% (43 minutes a day).³³

Since falls with injury became a Centers for Medicare and Medicaid Services nonreimbursable hospital-acquired condition, tension has arisen between promoting mobility and preventing falls.³⁴ Two studies evaluating the adoption of mobility-restricting approaches such as bed-alarms, “fall-alert” signs, supervision of patients in the bathroom, and ensuring patients’ walking aids are within reach, did not find a significant reduction in falls or fall-related injuries.^35,36

A clinically significant loss of community mobility is common after hospitalization in older adults.³⁷ Older adults who developed mobility impairment during hospitalization had a higher risk of death in a large, retrospective study.³⁸ A large Canadian multisite intervention trial³⁹ that promoted early mobilization in older patients who were admitted to general medical wards resulted in increased mobilization and significantly shorter hospital stays.

POSTHOSPITAL CARE NEEDS IMPROVEMENT

After hospitalization, older adults who have difficulty with activities of daily living or complex medical needs often require continued care.

About 20% of hospitalized Medicare beneficiaries in the United States are discharged to skilled nursing facilities.⁴⁰ This is often a stressful transition, and most people have little guidance on selecting a facility and simply choose one based on its proximity to home.⁴¹

A program of frequent visits by hospital-employed physicians and advanced practice professionals at skilled nursing facilities resulted in a significantly lower 30-day readmission rate compared with nonparticipating skilled nursing facilities in the same geographic area.⁴²

Home healthcare is recommended after hospital discharge at a rapidly increasing rate. Overall referral rates increased from 8.6% to 14.1% between 2001 and 2012, and from 14.3% to 24.0% for patients with heart failure.⁴³ A qualitative study of home healthcare nurses found a need for improved care coordination between home healthcare agencies and discharging hospitals, including defining accountability for orders and enhancing communication.⁴⁴

Unfortunately, recent research has not unveiled a breakthrough for preventing or treating cognitive impairment or Alzheimer disease. But several studies from the last 2 years are helping to drive the field of geriatrics forward, providing evidence of what does and does not help a variety of issues specific to the elderly. 

Based on a search of the 2017 and 2018 literature, this article presents new evidence on preventing and treating cognitive impairment, managing dementia-associated behavioral disturbances and delirium, preventing falls, and improving inpatient mobility and posthospital care transitions.

COGNITIVE IMPAIRMENT, DEMENTIA: STILL NO SILVER BULLET

With the exception of oral anticoagulation treatment for atrial fibrillation, there is little evidence that pharmacologic or nonpharmacologic interventions slow the onset or progression of Alzheimer disease.

Nonpharmacologic interventions

Home occupational therapy. A 2-year home-based occupational therapy intervention¹ showed no evidence of slowing functional decline in patients with Alzheimer disease. The randomized controlled trial involving 180 participants consisted of monthly sessions of an intensive, well-established collaborative-care management model that included fall prevention and other safety strategies, personalized training in activities of daily living, exercise, and education. Outcome measures for activities of daily living did not differ significantly between the treatment and control groups.¹

Physical activity. Whether physical activity interventions slow cognitive decline and prevent dementia in cognitively intact adults was examined in a systematic review of 32 trials.² Most of the trials followed patients for 6 months; a few stretched for 1 or 2 years.

Evidence was insufficient to prove cognitive benefit for short-term, single-component or multicomponent physical activity interventions. However, a multidomain physical activity intervention that also included dietary modifications and cognitive training did show a delay in cognitive decline, but only “low-strength” evidence.²

Nutritional supplements. The antioxidants vitamin E and selenium were studied for their possible cognitive benefit in the double-blind randomized Prevention of Alzheimer Disease by Vitamin E and Selenium trial³ in 3,786 asymptomatic men ages 60 and older. Neither supplement was found to prevent dementia over a 7-year follow-up period.

A review of 38 trials⁴ evaluated the effects on cognition of omega-3 fatty acids, soy, ginkgo biloba, B vitamins, vitamin D plus calcium, vitamin C, beta-carotene, and multi-ingredient supplements. It found insufficient evidence to recommend any over-the-counter supplement for cognitive protection in adults with normal cognition or mild cognitive impairment.

Pharmacologic treatments

Testosterone supplementation. The Testosterone Trials tested the effects of testosterone gel vs placebo for 1 year on 493 men over age 65 with low testosterone (< 275 ng/mL) and with subjective memory complaints and objective memory performance deficits. Treatment was not associated with improved memory or other cognitive functions compared with placebo.⁵

Antiamyloid drugs. A randomized, double-blind, placebo-controlled trial in nearly 2,000 patients evaluated verubecestat, an oral beta-site amyloid precursor protein-cleaving enzyme-1 inhibitor that reduces the amyloid-beta level in cerebrospinal fluid.⁶

Verubecestat did not reduce cognitive or functional decline in patients with mild-to-moderate Alzheimer disease, while adverse events including rashes, falls, injuries, sleep disturbances, suicidal ideation, weight loss, and hair color change were more common in the treatment groups. The trial was terminated early because of futility at 50 months.

And in a placebo-controlled trial of solanezumab, a monoclonal antibody directed against the amyloid beta peptide, no benefit was demonstrated at 80 weeks in more than 2,000 patients with Alzheimer disease.⁷

Multiple common agents. A well-conducted systematic review⁸ of 51 trials of at least a 6-month duration did not support the use of antihypertensive agents, diabetes medications, nonsteroidal anti-inflammatory drugs, aspirin, hormones, or lipid-lowering drugs for cognitive protection for people with normal cognition or mild cognitive impairment.

However, some studies found reassuring evidence that standard therapies for other conditions do not worsen cognitive decline and are protective for atrial fibrillation.⁸

Proton-pump inhibitors. Concern exists for a potential link between dementia risk and proton-pump inhibitors, which are widely used to treat acid-related gastrointestinal disorders.⁹

A prospective population-based cohort study¹⁰ of nearly 3,500 people ages 65 and older without baseline dementia screened participants for dementia every 2 years over a mean period of 7.5 years and provided further evaluation for those who screened positive. Use of proton-pump inhibitors was not found to be associated with dementia risk, even with high cumulative exposure.

Results from this study do not support avoiding proton-pump inhibitors out of concern for dementia risk, although long-term use is associated with other safety concerns.

Oral anticoagulation. The increased risk of dementia with atrial fibrillation is well documented.¹¹

A retrospective study¹² based on a Swedish health registry and using more than 444,000 patients covering more than 1.5 million years at risk found that oral anticoagulant treatment at baseline conferred a 29% lower risk of dementia in an intention-to-treat analysis and a 48% lower risk in on-treatment analysis compared with no oral anticoagulation therapy. No difference was found between new oral anticoagulants and warfarin.

Transcatheter aortic valve implantation is not associated with cognitive decline

For patients with severe aortic stenosis who are not surgical candidates, transcatheter aortic valve implantation is superior to standard medical therapy,¹³ but there are concerns of neurologic and cognitive changes after the procedure.¹⁴ A meta-analysis of 18 studies assessing cognitive performance in more than 1,000 patients (average age ≥ 80) after undergoing the procedure for severe aortic stenosis found no significant cognitive performance changes from baseline perioperatively or 3 or 6 months later.¹⁵

 

 

TREATING DEMENTIA-ASSOCIATED BEHAVIORAL DISTURBANCES

Behavioral and psychiatric symptoms often accompany dementia, but no drugs have yet been approved by the US Food and Drug Administration (FDA) to address them in this population. Nonpharmacologic interventions are recommended as first-line therapy.

Antipsychotics are not recommended

Antipsychotics are often prescribed,¹⁶ although they are associated with metabolic syndrome¹⁷ and increased risks of stroke and death.¹⁸ The FDA has issued black box warnings against using antipsychotics for behavioral management in patients with dementia. Further, the American Geriatrics Society and the American Psychiatric Association do not endorse using them as initial therapy for behavioral and psychological symptoms of dementia.^16,19

The Centers for Medicare and Medicaid Services partnered with nursing homes to improve the quality of care for patients with dementia, with results measured as the rate of prescribing antipsychotic medications. Although the use of psychotropic medications declined after initiating the partnership, the use of mood stabilizers increased, possibly as a substitute for antipsychotics.²⁰

Dextromethorphan-quinidine use is up, despite modest evidence of benefit

A consumer news report in 2017 stated that the use of dextromethorphan-quinidine in long-term care facilities increased by nearly 400% between 2012 and 2016.²¹

Evidence for its benefits comes from a 10-week, phase 2, randomized controlled trial conducted at 42 US study sites with 194 patients with probable Alzheimer disease. Compared with the placebo group, the active treatment group had mildly reduced agitation but an increased risk of falls, dizziness, and diarrhea. However, rates of adverse effects were low, and the authors concluded that treatment was generally well tolerated.²²

Pimavanserin: No long-term benefit for psychosis

In a phase 2, randomized, double-blind, placebo-controlled trial in 181 patients with possible or probable Alzheimer disease and psychotic symptoms, pimavanserin was associated with improved symptoms as measured by the Neuropsychiatric Inventory–Nursing Home Version psychosis score at 6 weeks, but no difference was found compared with placebo at 12 weeks. The treatment group had more adverse events, including agitation, aggression, peripheral edema, anxiety, and symptoms of dementia, although the differences were not statistically significant.²³               

DELIRIUM: AVOID ANTIPSYCHOTICS

Delirium is common in hospitalized older adults, especially those who have baseline cognitive or functional impairment and are exposed to precipitating factors such as treatment with anticholinergic or narcotic medications, infection, surgery, or admission to an intensive care unit.²⁴

Delirium at discharge predicts poor outcomes

In a prospective study of 152 hospitalized patients with delirium, those who either did not recover from delirium or had only partially recovered at discharge were more likely to visit the emergency department, be rehospitalized, or die during the subsequent 3 months than those who had fully recovered from delirium at discharge.²⁵

Multicomponent, patient-centered approach can help

A randomized trial in 377 patients in Taiwan evaluated the use of a modified Hospital Elder Life Program, consisting of 3 protocols focused on orienting communication, oral and nutritional assistance, and early mobilization. Patients were at least 65 years old and undergoing elective abdominal surgery with expected length of hospital stay longer than 6 days. The program, administered daily during hospitalization, significantly lowered postoperative delirium by 56% and hospital stay by 2 days compared with usual care.²⁶

Prophylactic haloperidol does not improve outcomes

In a multicenter randomized, double-blind, placebo-controlled trial, van den Boogaard et al studied prophylactic intravenous haloperidol in nearly 1,800 critically ill patients at high risk of delirium.²⁷ Haloperidol did not improve survival at 28 days compared with placebo. For secondary outcomes, including delirium incidence, delirium-free and coma-free days, duration of mechanical ventilation, and hospital and intensive care department length of stay, treatment was not found to differ statistically from placebo.

Antipsychotics may worsen delirium

A double-blind, parallel-arm, dose-titrated randomized trial, conducted at 11 Australian hospices or hospitals with palliative care services, administered oral risperidone, haloperidol, or placebo to 247 patients with life-limiting illness and delirium. Both treatment groups had higher delirium symptom scores than the placebo group.²⁸

In addition, a systematic review and meta-analysis of 19 studies found no benefit of antipsychotic medications for preventing or treating delirium in hospitalized adults.²⁹

Antipsychotics are often continued indefinitely

A retrospective chart review at a US academic health system found³⁰ that among 487 patients with a new antipsychotic medication prescribed during hospitalization, 147 (30.2%) were discharged on an antipsychotic. Of these, 121 (82.3%) had a diagnosis of delirium. Only 15 (12.4%) had discharge summaries that included instructions for discontinuing the drug.

Another US health system retrospectively reviewed antipsychotic use and found³¹ that out of 260 patients who were newly exposed to an antipsychotic drug during hospitalization, 146 (56.2%) were discharged on an antipsychotic drug, and 65% of these patients were still on the drug at the time of the next hospital admission.

 

 

EXERCISE, EXERCISE, EXERCISE

Exercise recommended, but not vitamin D, to prevent falls

In 2018, the US Preventive Services Task Force updated its recommendations for preventing falls in community-dwelling older adults.³² Based on the findings of several trials, the task force recommends exercise interventions for adults age 65 and older who are at increased risk for falls. Gait, balance, and functional training were studied in 17 trials, resistance training in 13, flexibility in 8, endurance training in 5, and tai chi in 3, with 5 studies including general physical activity. Exercise interventions most commonly took place for 3 sessions per week for 12 months (range 2–42 months).

The task force also recommends against vitamin D supplementation for fall prevention in community-dwelling adults age 65 or older who are not known to have osteoporosis or vitamin D deficiency.

Early mobilization helps inpatients

Hospitalized older adults usually spend most of their time in bed. Forty-five previously ambulatory patients (age ≥ 65 without dementia or delirium) in a Veterans Affairs hospital were monitored with wireless accelerometers and were found to spend, on average, 83% of the measured hospital stay in bed. Standing or walking time ranged from 0.2% to 21%, with a median of only 3% (43 minutes a day).³³

Since falls with injury became a Centers for Medicare and Medicaid Services nonreimbursable hospital-acquired condition, tension has arisen between promoting mobility and preventing falls.³⁴ Two studies evaluating the adoption of mobility-restricting approaches such as bed-alarms, “fall-alert” signs, supervision of patients in the bathroom, and ensuring patients’ walking aids are within reach, did not find a significant reduction in falls or fall-related injuries.^35,36

A clinically significant loss of community mobility is common after hospitalization in older adults.³⁷ Older adults who developed mobility impairment during hospitalization had a higher risk of death in a large, retrospective study.³⁸ A large Canadian multisite intervention trial³⁹ that promoted early mobilization in older patients who were admitted to general medical wards resulted in increased mobilization and significantly shorter hospital stays.

POSTHOSPITAL CARE NEEDS IMPROVEMENT

After hospitalization, older adults who have difficulty with activities of daily living or complex medical needs often require continued care.

About 20% of hospitalized Medicare beneficiaries in the United States are discharged to skilled nursing facilities.⁴⁰ This is often a stressful transition, and most people have little guidance on selecting a facility and simply choose one based on its proximity to home.⁴¹

A program of frequent visits by hospital-employed physicians and advanced practice professionals at skilled nursing facilities resulted in a significantly lower 30-day readmission rate compared with nonparticipating skilled nursing facilities in the same geographic area.⁴²

Home healthcare is recommended after hospital discharge at a rapidly increasing rate. Overall referral rates increased from 8.6% to 14.1% between 2001 and 2012, and from 14.3% to 24.0% for patients with heart failure.⁴³ A qualitative study of home healthcare nurses found a need for improved care coordination between home healthcare agencies and discharging hospitals, including defining accountability for orders and enhancing communication.⁴⁴