Literature Review

A novel biomarker could help identify progression in Parkinson’s disease, distinguish it from other neurodegenerative disorders, and monitor response to treatments. Although the biomarker, neurofilament light chain (NfL), is not especially specific, it is the first blood-based biomarker for Parkinson’s disease.

Neurofilaments are components of the neural cytoskeleton, where they maintain structure along with other functions. Following axonal damage, NfL gets released into extracellular fluids. Previously, NfL has been detected in cerebrospinal fluid (CSF) in patients with multiple sclerosis and neurodegenerative dementias. NfL in the CSF can distinguish Parkinson’s disease (PD) from multiple system atrophy and progressive supranuclear palsy.

That’s useful, but a serum marker would open new doors. “An easily accessible biomarker that will serve as an indicator of diagnosis, disease state, and progression, as well as a marker of response to therapeutic intervention is needed. A biomarker will strengthen the ability to select patients for inclusion or stratification within clinical trials,” commented Okeanis Vaou, MD, director of the movement disorders program at St. Elizabeth’s Medical Center in Brighton, Mass. Dr. Vaou was not involved in the study, which was published Aug. 15 in Movement Disorders.
 

A potential biomarker?

To determine if serum NfL levels would correlate with CSF values and had potential as a biomarker, a large, multi-institutional team of researchers led by Brit Mollenhauer, MD, of the University Medical Center Goettingen (Germany), and Danielle Graham, MD, of Biogen, drew data from a prospective, longitudinal, single-center project called the De Novo Parkinson’s disease (DeNoPa) cohort.

The researchers analyzed data from 176 subjects, including drug-naive patients with newly diagnosed PD; age, sex, and education matched healthy controls; and patients who were initially diagnosed with Parkinson’s disease but had their diagnoses changed to a cognate or neurodegenerative disorder (OND). The researchers also drew 514 serum samples from the prospective longitudinal, observational, international multicenter study Parkinson’s Progression Marker Initiative (PPMI) cohort.

In the DeNoPa cohort, OND patients had the highest median CSF NfL levels at baseline (839 pg/mL) followed by PD patients (562 pg/mL) and healthy controls (494 pg/mL; P = .01). There was a strong correlation between CSF and serum NfL levels in a cross-sectional exploratory study with the PPMI cohort.

Age and sex covariates in the PPMI cohort explained 51% of NfL variability. After adjustment for age and sex, baseline median blood NfL levels were highest in the OND group (16.23 pg/mL), followed by the genetic PD group (13.36 pg/mL), prodromal participants (12.20 pg/mL), PD patients (11.73 pg/mL), unaffected mutation carriers (11.63 pg/mL), and healthy controls (11.05 pg/mL; F test P < .0001). Median serum NfL increased by 3.35% per year of age (P < .0001), and median serum NfL was 6.79% higher in women (P = .0002).

Doubling of adjusted serum NfL levels were associated with a median increase in the Movement Disorder Society Unified Parkinson’s Disease Rating Scale total score of 3.45 points (false-discovery rate–adjusted P = .0115), a median decrease in Symbol Digit Modality Test total score of 1.39 (FDR P = .026), a median decrease in Hopkins Verbal Learning Tests with discrimination recognition score of 0.3 (FDR P = .03), and a median decrease in Hopkins Verbal Learning Tests with retention score of 0.029 (FDR P = .04).
 

More specific markers needed

The findings are intriguing, said Dr Vaou, but “we need to acknowledge that increased NfL levels are not specific enough to Parkinson’s disease and reflect neuronal and axonal damage. Therefore, there is a need for more specific markers to support diagnostic accuracy, rate of progression, and ultimate prognosis. A serum NfL assay may be useful to clinicians evaluating patients with PD or OND diagnosis and mitigate the misdiagnosis of atypical PD. NfL may be particularly useful in differentiating PD from cognate disorders such as multiple system atrophy, progressive supranuclear palsy, and dementia with Lewy bodies.”

The current success is the result of large patient databases containing phenotypic data, imaging, and tests of tissue, blood, and cerebrospinal fluid, along with collaborations between advocacy groups, academia, and industry, according to Dr. Vaou. As that work continues, it could uncover more specific biomarkers “that will allow us not only to help with diagnosis and treatment but with disease progression, inclusion, recruitment and stratification in clinical studies, as well as (be an) indicator of response to therapeutic intervention of an investigational drug.”

The study was funded by the Michael J. Fox Foundation for Parkinson’s Research. Dr. Vaou had no relevant financial disclosures.

SOURCE: Mollenhauer B et al. Mov Disord. 2020 Aug 15. doi: 10.1002/mds.28206.

A novel biomarker could help identify progression in Parkinson’s disease, distinguish it from other neurodegenerative disorders, and monitor response to treatments. Although the biomarker, neurofilament light chain (NfL), is not especially specific, it is the first blood-based biomarker for Parkinson’s disease.

Neurofilaments are components of the neural cytoskeleton, where they maintain structure along with other functions. Following axonal damage, NfL gets released into extracellular fluids. Previously, NfL has been detected in cerebrospinal fluid (CSF) in patients with multiple sclerosis and neurodegenerative dementias. NfL in the CSF can distinguish Parkinson’s disease (PD) from multiple system atrophy and progressive supranuclear palsy.

That’s useful, but a serum marker would open new doors. “An easily accessible biomarker that will serve as an indicator of diagnosis, disease state, and progression, as well as a marker of response to therapeutic intervention is needed. A biomarker will strengthen the ability to select patients for inclusion or stratification within clinical trials,” commented Okeanis Vaou, MD, director of the movement disorders program at St. Elizabeth’s Medical Center in Brighton, Mass. Dr. Vaou was not involved in the study, which was published Aug. 15 in Movement Disorders.
 

A potential biomarker?

To determine if serum NfL levels would correlate with CSF values and had potential as a biomarker, a large, multi-institutional team of researchers led by Brit Mollenhauer, MD, of the University Medical Center Goettingen (Germany), and Danielle Graham, MD, of Biogen, drew data from a prospective, longitudinal, single-center project called the De Novo Parkinson’s disease (DeNoPa) cohort.

The researchers analyzed data from 176 subjects, including drug-naive patients with newly diagnosed PD; age, sex, and education matched healthy controls; and patients who were initially diagnosed with Parkinson’s disease but had their diagnoses changed to a cognate or neurodegenerative disorder (OND). The researchers also drew 514 serum samples from the prospective longitudinal, observational, international multicenter study Parkinson’s Progression Marker Initiative (PPMI) cohort.

In the DeNoPa cohort, OND patients had the highest median CSF NfL levels at baseline (839 pg/mL) followed by PD patients (562 pg/mL) and healthy controls (494 pg/mL; P = .01). There was a strong correlation between CSF and serum NfL levels in a cross-sectional exploratory study with the PPMI cohort.

Age and sex covariates in the PPMI cohort explained 51% of NfL variability. After adjustment for age and sex, baseline median blood NfL levels were highest in the OND group (16.23 pg/mL), followed by the genetic PD group (13.36 pg/mL), prodromal participants (12.20 pg/mL), PD patients (11.73 pg/mL), unaffected mutation carriers (11.63 pg/mL), and healthy controls (11.05 pg/mL; F test P < .0001). Median serum NfL increased by 3.35% per year of age (P < .0001), and median serum NfL was 6.79% higher in women (P = .0002).

Doubling of adjusted serum NfL levels were associated with a median increase in the Movement Disorder Society Unified Parkinson’s Disease Rating Scale total score of 3.45 points (false-discovery rate–adjusted P = .0115), a median decrease in Symbol Digit Modality Test total score of 1.39 (FDR P = .026), a median decrease in Hopkins Verbal Learning Tests with discrimination recognition score of 0.3 (FDR P = .03), and a median decrease in Hopkins Verbal Learning Tests with retention score of 0.029 (FDR P = .04).
 

More specific markers needed

The findings are intriguing, said Dr Vaou, but “we need to acknowledge that increased NfL levels are not specific enough to Parkinson’s disease and reflect neuronal and axonal damage. Therefore, there is a need for more specific markers to support diagnostic accuracy, rate of progression, and ultimate prognosis. A serum NfL assay may be useful to clinicians evaluating patients with PD or OND diagnosis and mitigate the misdiagnosis of atypical PD. NfL may be particularly useful in differentiating PD from cognate disorders such as multiple system atrophy, progressive supranuclear palsy, and dementia with Lewy bodies.”

The current success is the result of large patient databases containing phenotypic data, imaging, and tests of tissue, blood, and cerebrospinal fluid, along with collaborations between advocacy groups, academia, and industry, according to Dr. Vaou. As that work continues, it could uncover more specific biomarkers “that will allow us not only to help with diagnosis and treatment but with disease progression, inclusion, recruitment and stratification in clinical studies, as well as (be an) indicator of response to therapeutic intervention of an investigational drug.”

The study was funded by the Michael J. Fox Foundation for Parkinson’s Research. Dr. Vaou had no relevant financial disclosures.

SOURCE: Mollenhauer B et al. Mov Disord. 2020 Aug 15. doi: 10.1002/mds.28206.

A novel biomarker could help identify progression in Parkinson’s disease, distinguish it from other neurodegenerative disorders, and monitor response to treatments. Although the biomarker, neurofilament light chain (NfL), is not especially specific, it is the first blood-based biomarker for Parkinson’s disease.

Neurofilaments are components of the neural cytoskeleton, where they maintain structure along with other functions. Following axonal damage, NfL gets released into extracellular fluids. Previously, NfL has been detected in cerebrospinal fluid (CSF) in patients with multiple sclerosis and neurodegenerative dementias. NfL in the CSF can distinguish Parkinson’s disease (PD) from multiple system atrophy and progressive supranuclear palsy.

That’s useful, but a serum marker would open new doors. “An easily accessible biomarker that will serve as an indicator of diagnosis, disease state, and progression, as well as a marker of response to therapeutic intervention is needed. A biomarker will strengthen the ability to select patients for inclusion or stratification within clinical trials,” commented Okeanis Vaou, MD, director of the movement disorders program at St. Elizabeth’s Medical Center in Brighton, Mass. Dr. Vaou was not involved in the study, which was published Aug. 15 in Movement Disorders.
 

A potential biomarker?

To determine if serum NfL levels would correlate with CSF values and had potential as a biomarker, a large, multi-institutional team of researchers led by Brit Mollenhauer, MD, of the University Medical Center Goettingen (Germany), and Danielle Graham, MD, of Biogen, drew data from a prospective, longitudinal, single-center project called the De Novo Parkinson’s disease (DeNoPa) cohort.

The researchers analyzed data from 176 subjects, including drug-naive patients with newly diagnosed PD; age, sex, and education matched healthy controls; and patients who were initially diagnosed with Parkinson’s disease but had their diagnoses changed to a cognate or neurodegenerative disorder (OND). The researchers also drew 514 serum samples from the prospective longitudinal, observational, international multicenter study Parkinson’s Progression Marker Initiative (PPMI) cohort.

In the DeNoPa cohort, OND patients had the highest median CSF NfL levels at baseline (839 pg/mL) followed by PD patients (562 pg/mL) and healthy controls (494 pg/mL; P = .01). There was a strong correlation between CSF and serum NfL levels in a cross-sectional exploratory study with the PPMI cohort.

Age and sex covariates in the PPMI cohort explained 51% of NfL variability. After adjustment for age and sex, baseline median blood NfL levels were highest in the OND group (16.23 pg/mL), followed by the genetic PD group (13.36 pg/mL), prodromal participants (12.20 pg/mL), PD patients (11.73 pg/mL), unaffected mutation carriers (11.63 pg/mL), and healthy controls (11.05 pg/mL; F test P < .0001). Median serum NfL increased by 3.35% per year of age (P < .0001), and median serum NfL was 6.79% higher in women (P = .0002).

Doubling of adjusted serum NfL levels were associated with a median increase in the Movement Disorder Society Unified Parkinson’s Disease Rating Scale total score of 3.45 points (false-discovery rate–adjusted P = .0115), a median decrease in Symbol Digit Modality Test total score of 1.39 (FDR P = .026), a median decrease in Hopkins Verbal Learning Tests with discrimination recognition score of 0.3 (FDR P = .03), and a median decrease in Hopkins Verbal Learning Tests with retention score of 0.029 (FDR P = .04).
 

More specific markers needed

The findings are intriguing, said Dr Vaou, but “we need to acknowledge that increased NfL levels are not specific enough to Parkinson’s disease and reflect neuronal and axonal damage. Therefore, there is a need for more specific markers to support diagnostic accuracy, rate of progression, and ultimate prognosis. A serum NfL assay may be useful to clinicians evaluating patients with PD or OND diagnosis and mitigate the misdiagnosis of atypical PD. NfL may be particularly useful in differentiating PD from cognate disorders such as multiple system atrophy, progressive supranuclear palsy, and dementia with Lewy bodies.”

The current success is the result of large patient databases containing phenotypic data, imaging, and tests of tissue, blood, and cerebrospinal fluid, along with collaborations between advocacy groups, academia, and industry, according to Dr. Vaou. As that work continues, it could uncover more specific biomarkers “that will allow us not only to help with diagnosis and treatment but with disease progression, inclusion, recruitment and stratification in clinical studies, as well as (be an) indicator of response to therapeutic intervention of an investigational drug.”

The study was funded by the Michael J. Fox Foundation for Parkinson’s Research. Dr. Vaou had no relevant financial disclosures.

SOURCE: Mollenhauer B et al. Mov Disord. 2020 Aug 15. doi: 10.1002/mds.28206.

A new study has found that reducing rituximab dosage from 1,000 mg/6 months to 500 mg/6 months is a safe and stable choice for patients with multiple sclerosis (MS).

“Given its favorable cost-effectiveness profile, [rituximab] remains a valuable treatment option in the current landscape of MS treatments, even at the reduced dose,” wrote Giulio Disanto, MD, PhD, of the Neurocenter of Southern Switzerland in Lugano, and coauthors. The study was published in Multiple Sclerosis Journal.

To determine the clinical and radiologic effectiveness of deescalating rituximab dosage – along with assessing any adverse outcomes – this observational, single-center study examined 59 patients with MS who had been treated with rituximab at 1,000 mg for at least 1 year before the study began. Roughly 63% (n = 37) of the patients had relapsing remitting MS (RRMS), while the rest (n = 22) had secondary progressive disease (SPD). Their median age was 51, and nearly 75% were women.

All patients underwent neurologic examinations at baseline and then every 3 months for 1 year, with new symptoms, infections, or adverse events being assessed via the Expanded Disability Status Scale (EDSS). They also underwent brain and spinal MRI at baseline and at 12 months while blood samples were taken at baseline and then every 3 months for 1 year, with previous data for both collected when available.
 

Study results

All 59 patients completed 12-month follow-up, and no relapses occurred in the year after lowering rituximab dosage to 500 mg. No significant differences were observed when comparing EDSS scores at the start of the 1,000-mg dose with the start of the 500-mg dose (Wilcoxon P = .131) as well as from the start of the 500-mg dose to the end of follow-up (Wilcoxon P = .284). Analyzing RRMS and SPD patients separately also led to no differences in EDSS scores from the start of the 500-mg dose to the end of follow-up (Wilcoxon P = .531; Wilcoxon P = .408).

During the 1,000-mg treatment period the number of patients who developed at least one new T2 lesion on their brain or spine was 9 and 4, respectively. During the 500-mg period, just one patient developed a new T2 brain lesion and two patients developed new T2 spine lesions. IgG and IgM levels did not change from the start of 500-mg treatment, although total dose of rituximab was inversely associated with IgG concentrations when previous treatment with 1,000 mg was factored in (coefficient, −0.439; P = 0.041).

A total of 33 patients reported at least one adverse event during the 500-mg treatment period, with only three events being classified as serious: one pancreatitis, one coronary stenting, and one neutropenia.
 

Validating clinical experience

“This randomized trial is an important step,” said Timothy Vollmer, MD, of the Rocky Mountain MS Center in Westminster, Colo., in an interview. “It clearly supports that you can lessen the dose, which will allow us to use this revolutionary drug for a longer period of time in patients.”

Dr. Vollmer noted that, at his center, they have been using 500 mg of rituximab over a 6-month period since 2010 without a formal clinical trial and with no notable difference in adverse outcomes on MRIs or disability scales. “This validates what we’ve been doing, which we appreciate,” he said.

“The next thing you have to do is determine whether you really have to give it every 6 months,” he added, “because the treatment effect in most patients will last, in terms of B-cell depletion, about a year or more. What we should be testing next is giving the 500 mg and waiting until patients begin to recover B cells before we give them the next cycle, to see if that helps decrease the major side effect, which is a drop in IgG levels.”

The authors acknowledged their study’s limitations, including a moderate sample size, a short follow-up period after 500-mg dosage, and an inability to confirm consistency among 1,000-mg dose administration among all patients, which “may well influence efficacy and safety measures.”

The study was supported by the Neurocenter of Southern Switzerland. One author declared numerous potential conflicts of interest, including receiving speaker fees, research fees, and travel support, and serving on advisory boards for various foundations, universities, and pharmaceutical companies.

SOURCE: Disanto G et al. Mult Scler J. 2020 Aug 25. doi: 10.1177/1352458520952036.

A new study has found that reducing rituximab dosage from 1,000 mg/6 months to 500 mg/6 months is a safe and stable choice for patients with multiple sclerosis (MS).

“Given its favorable cost-effectiveness profile, [rituximab] remains a valuable treatment option in the current landscape of MS treatments, even at the reduced dose,” wrote Giulio Disanto, MD, PhD, of the Neurocenter of Southern Switzerland in Lugano, and coauthors. The study was published in Multiple Sclerosis Journal.

To determine the clinical and radiologic effectiveness of deescalating rituximab dosage – along with assessing any adverse outcomes – this observational, single-center study examined 59 patients with MS who had been treated with rituximab at 1,000 mg for at least 1 year before the study began. Roughly 63% (n = 37) of the patients had relapsing remitting MS (RRMS), while the rest (n = 22) had secondary progressive disease (SPD). Their median age was 51, and nearly 75% were women.

All patients underwent neurologic examinations at baseline and then every 3 months for 1 year, with new symptoms, infections, or adverse events being assessed via the Expanded Disability Status Scale (EDSS). They also underwent brain and spinal MRI at baseline and at 12 months while blood samples were taken at baseline and then every 3 months for 1 year, with previous data for both collected when available.
 

Study results

All 59 patients completed 12-month follow-up, and no relapses occurred in the year after lowering rituximab dosage to 500 mg. No significant differences were observed when comparing EDSS scores at the start of the 1,000-mg dose with the start of the 500-mg dose (Wilcoxon P = .131) as well as from the start of the 500-mg dose to the end of follow-up (Wilcoxon P = .284). Analyzing RRMS and SPD patients separately also led to no differences in EDSS scores from the start of the 500-mg dose to the end of follow-up (Wilcoxon P = .531; Wilcoxon P = .408).

During the 1,000-mg treatment period the number of patients who developed at least one new T2 lesion on their brain or spine was 9 and 4, respectively. During the 500-mg period, just one patient developed a new T2 brain lesion and two patients developed new T2 spine lesions. IgG and IgM levels did not change from the start of 500-mg treatment, although total dose of rituximab was inversely associated with IgG concentrations when previous treatment with 1,000 mg was factored in (coefficient, −0.439; P = 0.041).

A total of 33 patients reported at least one adverse event during the 500-mg treatment period, with only three events being classified as serious: one pancreatitis, one coronary stenting, and one neutropenia.
 

Validating clinical experience

“This randomized trial is an important step,” said Timothy Vollmer, MD, of the Rocky Mountain MS Center in Westminster, Colo., in an interview. “It clearly supports that you can lessen the dose, which will allow us to use this revolutionary drug for a longer period of time in patients.”

Dr. Vollmer noted that, at his center, they have been using 500 mg of rituximab over a 6-month period since 2010 without a formal clinical trial and with no notable difference in adverse outcomes on MRIs or disability scales. “This validates what we’ve been doing, which we appreciate,” he said.

“The next thing you have to do is determine whether you really have to give it every 6 months,” he added, “because the treatment effect in most patients will last, in terms of B-cell depletion, about a year or more. What we should be testing next is giving the 500 mg and waiting until patients begin to recover B cells before we give them the next cycle, to see if that helps decrease the major side effect, which is a drop in IgG levels.”

The authors acknowledged their study’s limitations, including a moderate sample size, a short follow-up period after 500-mg dosage, and an inability to confirm consistency among 1,000-mg dose administration among all patients, which “may well influence efficacy and safety measures.”

The study was supported by the Neurocenter of Southern Switzerland. One author declared numerous potential conflicts of interest, including receiving speaker fees, research fees, and travel support, and serving on advisory boards for various foundations, universities, and pharmaceutical companies.

SOURCE: Disanto G et al. Mult Scler J. 2020 Aug 25. doi: 10.1177/1352458520952036.

A new study has found that reducing rituximab dosage from 1,000 mg/6 months to 500 mg/6 months is a safe and stable choice for patients with multiple sclerosis (MS).

“Given its favorable cost-effectiveness profile, [rituximab] remains a valuable treatment option in the current landscape of MS treatments, even at the reduced dose,” wrote Giulio Disanto, MD, PhD, of the Neurocenter of Southern Switzerland in Lugano, and coauthors. The study was published in Multiple Sclerosis Journal.

To determine the clinical and radiologic effectiveness of deescalating rituximab dosage – along with assessing any adverse outcomes – this observational, single-center study examined 59 patients with MS who had been treated with rituximab at 1,000 mg for at least 1 year before the study began. Roughly 63% (n = 37) of the patients had relapsing remitting MS (RRMS), while the rest (n = 22) had secondary progressive disease (SPD). Their median age was 51, and nearly 75% were women.

All patients underwent neurologic examinations at baseline and then every 3 months for 1 year, with new symptoms, infections, or adverse events being assessed via the Expanded Disability Status Scale (EDSS). They also underwent brain and spinal MRI at baseline and at 12 months while blood samples were taken at baseline and then every 3 months for 1 year, with previous data for both collected when available.
 

Study results

All 59 patients completed 12-month follow-up, and no relapses occurred in the year after lowering rituximab dosage to 500 mg. No significant differences were observed when comparing EDSS scores at the start of the 1,000-mg dose with the start of the 500-mg dose (Wilcoxon P = .131) as well as from the start of the 500-mg dose to the end of follow-up (Wilcoxon P = .284). Analyzing RRMS and SPD patients separately also led to no differences in EDSS scores from the start of the 500-mg dose to the end of follow-up (Wilcoxon P = .531; Wilcoxon P = .408).

During the 1,000-mg treatment period the number of patients who developed at least one new T2 lesion on their brain or spine was 9 and 4, respectively. During the 500-mg period, just one patient developed a new T2 brain lesion and two patients developed new T2 spine lesions. IgG and IgM levels did not change from the start of 500-mg treatment, although total dose of rituximab was inversely associated with IgG concentrations when previous treatment with 1,000 mg was factored in (coefficient, −0.439; P = 0.041).

A total of 33 patients reported at least one adverse event during the 500-mg treatment period, with only three events being classified as serious: one pancreatitis, one coronary stenting, and one neutropenia.
 

Validating clinical experience

“This randomized trial is an important step,” said Timothy Vollmer, MD, of the Rocky Mountain MS Center in Westminster, Colo., in an interview. “It clearly supports that you can lessen the dose, which will allow us to use this revolutionary drug for a longer period of time in patients.”

Dr. Vollmer noted that, at his center, they have been using 500 mg of rituximab over a 6-month period since 2010 without a formal clinical trial and with no notable difference in adverse outcomes on MRIs or disability scales. “This validates what we’ve been doing, which we appreciate,” he said.

“The next thing you have to do is determine whether you really have to give it every 6 months,” he added, “because the treatment effect in most patients will last, in terms of B-cell depletion, about a year or more. What we should be testing next is giving the 500 mg and waiting until patients begin to recover B cells before we give them the next cycle, to see if that helps decrease the major side effect, which is a drop in IgG levels.”

The authors acknowledged their study’s limitations, including a moderate sample size, a short follow-up period after 500-mg dosage, and an inability to confirm consistency among 1,000-mg dose administration among all patients, which “may well influence efficacy and safety measures.”

The study was supported by the Neurocenter of Southern Switzerland. One author declared numerous potential conflicts of interest, including receiving speaker fees, research fees, and travel support, and serving on advisory boards for various foundations, universities, and pharmaceutical companies.

SOURCE: Disanto G et al. Mult Scler J. 2020 Aug 25. doi: 10.1177/1352458520952036.

Treatment with a fixed-dose combination of sodium phenylbutyrate and taurursodiol (AMX0035, Amylyx Pharmaceuticals) slows the rate of decline in physical function in patients with amyotrophic lateral sclerosis (ALS), according to results of the phase 2/3 CENTAUR study.

Patients with a fast-progressing form of ALS who were treated with AMX0035 “retained higher levels of physical function over 6 months compared with those who received placebo,” reported principal investigator Sabrina Paganoni, MD, PhD, of the Sean M. Healey and AMG Center for ALS at Massachusetts General Hospital, Boston.

“This is very hopeful news for people affected by ALS, especially because we were able to see a treatment effect in a relatively short period of time,” Dr. Paganoni said.

The study was published online Sept. 3 in the New England Journal of Medicine.

In this study, AMX0035 demonstrated a “clinically meaningful benefit and a favorable safety profile for people living with ALS,” Josh Cohen, co-CEO, chairman, and cofounder at Amylyx, said in a news release. The company is “working collaboratively and expeditiously with agencies worldwide to bring this potential new treatment option forward.”

“The data ... makes a clear and compelling case that AMX0035 should be made available to people with ALS as soon as possible,” Calaneet Balas, president and CEO of The ALS Association, said in the release.

The CENTAUR trial

Sodium phenylbutyrate and taurursodiol have been found to reduce neuronal death in experimental models. AMX0035 combines 3 g sodium phenylbutyrate and 1 g of taurursodiol.

The CENTAUR trial tested AMX0035 against placebo in 137 ALS patients with symptom onset within the prior 18 months, with 89 patients in the AMX0035 group and 48 in the placebo group. AMX0035 or matching placebo were administered once daily for 3 weeks and then twice daily for a planned duration of 24 weeks.

In a modified intention-to-treat analysis, the mean rate of change in the Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised (ALSFRS-R) score was −1.24 points per month with AMX0035 and −1.66 points per month with placebo (difference, 0.42 points per month; 95% CI, 0.03 - 0.81; P = .03). After 24 weeks, patients treated with AMX0035 scored on average 2.32 points higher on the ALSFRS-R than their peers on placebo group (P = .03).

“The score, consisting of four subdomains, showed a change that was most prominent for the fine-motor subscale and less apparent for the other subscales,” the investigators said.

Treatment with AMX0035 led to slowing of disease progression in a population in which many participants were receiving riluzole (Tiglutik), edaravone (Radicava) or both, they pointed out.

The secondary outcomes were rate of decline in isometric muscle strength and breathing function; change in plasma phosphorylated axonal neurofilament H subunit (pNF-H) levels; and the time to composite events of death, tracheostomy, permanent ventilation, and hospitalization. These outcomes did not differ significantly between the two groups.

Open-label extension ongoing

AMX0035 was generally well tolerated. Nearly all patients in both groups had one or more adverse events. Events occurring at 2% or greater frequency in the AMX0035 group were primarily gastrointestinal (diarrhea, nausea, salivary hypersecretion, and abdominal discomfort). Serious adverse events were more common in the placebo group (19% vs. 12%). The incidence of respiratory serious adverse events was 8% in the placebo group and 3% in the AMX0035 group.

More patients on active treatment than placebo (19% vs. 8%) stopped the trial regimen early owing to adverse events. The most common adverse events leading to discontinuation of the trial regimen were diarrhea and respiratory failure.

The trial was “too short for us to detect an effect on survival,” Dr. Paganoni said in an interview. Most of the participants who completed the trial elected to enroll in an open-label extension study and receive AMX0035 long-term. “This is important because it will teach us about the impact of AMX0035 on survival,” said Dr. Paganoni.

Interim data from the ongoing open-label extension study are being submitted to a peer-reviewed journal shortly and will be published in the coming months.
 

A cause for hope

“There has been understandable frustration with the slow pace of development of therapy for ALS,” Michael Benatar, MD, PhD, University of Miami, and Michael McDermott, PhD, University of Rochester (N.Y.), said in an accompanying editorial.

“Despite dozens of trials, few pharmacologic agents have emerged that affect functional decline or survival – and all only modestly so. Although the effects of sodium phenylbutyrate–taurursodiol are similarly modest, the incremental gains that they provide in the battle against ALS are a cause for hope,” they wrote.

They caution, however, that this study was enriched for patients with more rapidly progressive disease, which “raises questions about generalizability to the broader population of patients with ALS.

“Although the patients who were enrolled in the trial may not be biologically different from the broader population of patients with ALS, the magnitude of therapeutic effect may be smaller in the latter,” Dr. Benatar and Dr. McDermott noted.

They said that in light of “residual questions about efficacy and the ability of patients to continue taking the drug,” they agree with the authors’ conclusion that “longer and larger trials are needed to evaluate the efficacy and safety of sodium phenylbutyrate–taurursodiol in persons with ALS.”

Given these “tantalizing preliminary data,” Dr. Benatar and Dr. McDermott said they look forward to “a confirmatory phase 3 trial.” 

The study was supported by Amylyx Pharmaceuticals, the ALS Finding a Cure Foundation, and the ALS Association. Dr. Paganoni has received grants from Revalesio, Ra Pharma, Biohaven, Clene, and Prilenia. A complete list of disclosures for authors and editorialists is available with the original article.

A version of this article originally appeared on Medscape.com.

Treatment with a fixed-dose combination of sodium phenylbutyrate and taurursodiol (AMX0035, Amylyx Pharmaceuticals) slows the rate of decline in physical function in patients with amyotrophic lateral sclerosis (ALS), according to results of the phase 2/3 CENTAUR study.

Patients with a fast-progressing form of ALS who were treated with AMX0035 “retained higher levels of physical function over 6 months compared with those who received placebo,” reported principal investigator Sabrina Paganoni, MD, PhD, of the Sean M. Healey and AMG Center for ALS at Massachusetts General Hospital, Boston.

“This is very hopeful news for people affected by ALS, especially because we were able to see a treatment effect in a relatively short period of time,” Dr. Paganoni said.

The study was published online Sept. 3 in the New England Journal of Medicine.

In this study, AMX0035 demonstrated a “clinically meaningful benefit and a favorable safety profile for people living with ALS,” Josh Cohen, co-CEO, chairman, and cofounder at Amylyx, said in a news release. The company is “working collaboratively and expeditiously with agencies worldwide to bring this potential new treatment option forward.”

“The data ... makes a clear and compelling case that AMX0035 should be made available to people with ALS as soon as possible,” Calaneet Balas, president and CEO of The ALS Association, said in the release.

The CENTAUR trial

Sodium phenylbutyrate and taurursodiol have been found to reduce neuronal death in experimental models. AMX0035 combines 3 g sodium phenylbutyrate and 1 g of taurursodiol.

The CENTAUR trial tested AMX0035 against placebo in 137 ALS patients with symptom onset within the prior 18 months, with 89 patients in the AMX0035 group and 48 in the placebo group. AMX0035 or matching placebo were administered once daily for 3 weeks and then twice daily for a planned duration of 24 weeks.

In a modified intention-to-treat analysis, the mean rate of change in the Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised (ALSFRS-R) score was −1.24 points per month with AMX0035 and −1.66 points per month with placebo (difference, 0.42 points per month; 95% CI, 0.03 - 0.81; P = .03). After 24 weeks, patients treated with AMX0035 scored on average 2.32 points higher on the ALSFRS-R than their peers on placebo group (P = .03).

“The score, consisting of four subdomains, showed a change that was most prominent for the fine-motor subscale and less apparent for the other subscales,” the investigators said.

Treatment with AMX0035 led to slowing of disease progression in a population in which many participants were receiving riluzole (Tiglutik), edaravone (Radicava) or both, they pointed out.

The secondary outcomes were rate of decline in isometric muscle strength and breathing function; change in plasma phosphorylated axonal neurofilament H subunit (pNF-H) levels; and the time to composite events of death, tracheostomy, permanent ventilation, and hospitalization. These outcomes did not differ significantly between the two groups.

Open-label extension ongoing

AMX0035 was generally well tolerated. Nearly all patients in both groups had one or more adverse events. Events occurring at 2% or greater frequency in the AMX0035 group were primarily gastrointestinal (diarrhea, nausea, salivary hypersecretion, and abdominal discomfort). Serious adverse events were more common in the placebo group (19% vs. 12%). The incidence of respiratory serious adverse events was 8% in the placebo group and 3% in the AMX0035 group.

More patients on active treatment than placebo (19% vs. 8%) stopped the trial regimen early owing to adverse events. The most common adverse events leading to discontinuation of the trial regimen were diarrhea and respiratory failure.

The trial was “too short for us to detect an effect on survival,” Dr. Paganoni said in an interview. Most of the participants who completed the trial elected to enroll in an open-label extension study and receive AMX0035 long-term. “This is important because it will teach us about the impact of AMX0035 on survival,” said Dr. Paganoni.

Interim data from the ongoing open-label extension study are being submitted to a peer-reviewed journal shortly and will be published in the coming months.
 

A cause for hope

“There has been understandable frustration with the slow pace of development of therapy for ALS,” Michael Benatar, MD, PhD, University of Miami, and Michael McDermott, PhD, University of Rochester (N.Y.), said in an accompanying editorial.

“Despite dozens of trials, few pharmacologic agents have emerged that affect functional decline or survival – and all only modestly so. Although the effects of sodium phenylbutyrate–taurursodiol are similarly modest, the incremental gains that they provide in the battle against ALS are a cause for hope,” they wrote.

They caution, however, that this study was enriched for patients with more rapidly progressive disease, which “raises questions about generalizability to the broader population of patients with ALS.

“Although the patients who were enrolled in the trial may not be biologically different from the broader population of patients with ALS, the magnitude of therapeutic effect may be smaller in the latter,” Dr. Benatar and Dr. McDermott noted.

They said that in light of “residual questions about efficacy and the ability of patients to continue taking the drug,” they agree with the authors’ conclusion that “longer and larger trials are needed to evaluate the efficacy and safety of sodium phenylbutyrate–taurursodiol in persons with ALS.”

Given these “tantalizing preliminary data,” Dr. Benatar and Dr. McDermott said they look forward to “a confirmatory phase 3 trial.” 

The study was supported by Amylyx Pharmaceuticals, the ALS Finding a Cure Foundation, and the ALS Association. Dr. Paganoni has received grants from Revalesio, Ra Pharma, Biohaven, Clene, and Prilenia. A complete list of disclosures for authors and editorialists is available with the original article.

A version of this article originally appeared on Medscape.com.

Treatment with a fixed-dose combination of sodium phenylbutyrate and taurursodiol (AMX0035, Amylyx Pharmaceuticals) slows the rate of decline in physical function in patients with amyotrophic lateral sclerosis (ALS), according to results of the phase 2/3 CENTAUR study.

Patients with a fast-progressing form of ALS who were treated with AMX0035 “retained higher levels of physical function over 6 months compared with those who received placebo,” reported principal investigator Sabrina Paganoni, MD, PhD, of the Sean M. Healey and AMG Center for ALS at Massachusetts General Hospital, Boston.

“This is very hopeful news for people affected by ALS, especially because we were able to see a treatment effect in a relatively short period of time,” Dr. Paganoni said.

The study was published online Sept. 3 in the New England Journal of Medicine.

In this study, AMX0035 demonstrated a “clinically meaningful benefit and a favorable safety profile for people living with ALS,” Josh Cohen, co-CEO, chairman, and cofounder at Amylyx, said in a news release. The company is “working collaboratively and expeditiously with agencies worldwide to bring this potential new treatment option forward.”

“The data ... makes a clear and compelling case that AMX0035 should be made available to people with ALS as soon as possible,” Calaneet Balas, president and CEO of The ALS Association, said in the release.

The CENTAUR trial

Sodium phenylbutyrate and taurursodiol have been found to reduce neuronal death in experimental models. AMX0035 combines 3 g sodium phenylbutyrate and 1 g of taurursodiol.

The CENTAUR trial tested AMX0035 against placebo in 137 ALS patients with symptom onset within the prior 18 months, with 89 patients in the AMX0035 group and 48 in the placebo group. AMX0035 or matching placebo were administered once daily for 3 weeks and then twice daily for a planned duration of 24 weeks.

In a modified intention-to-treat analysis, the mean rate of change in the Amyotrophic Lateral Sclerosis Functional Rating Scale–Revised (ALSFRS-R) score was −1.24 points per month with AMX0035 and −1.66 points per month with placebo (difference, 0.42 points per month; 95% CI, 0.03 - 0.81; P = .03). After 24 weeks, patients treated with AMX0035 scored on average 2.32 points higher on the ALSFRS-R than their peers on placebo group (P = .03).

“The score, consisting of four subdomains, showed a change that was most prominent for the fine-motor subscale and less apparent for the other subscales,” the investigators said.

Treatment with AMX0035 led to slowing of disease progression in a population in which many participants were receiving riluzole (Tiglutik), edaravone (Radicava) or both, they pointed out.

The secondary outcomes were rate of decline in isometric muscle strength and breathing function; change in plasma phosphorylated axonal neurofilament H subunit (pNF-H) levels; and the time to composite events of death, tracheostomy, permanent ventilation, and hospitalization. These outcomes did not differ significantly between the two groups.

Open-label extension ongoing

AMX0035 was generally well tolerated. Nearly all patients in both groups had one or more adverse events. Events occurring at 2% or greater frequency in the AMX0035 group were primarily gastrointestinal (diarrhea, nausea, salivary hypersecretion, and abdominal discomfort). Serious adverse events were more common in the placebo group (19% vs. 12%). The incidence of respiratory serious adverse events was 8% in the placebo group and 3% in the AMX0035 group.

More patients on active treatment than placebo (19% vs. 8%) stopped the trial regimen early owing to adverse events. The most common adverse events leading to discontinuation of the trial regimen were diarrhea and respiratory failure.

The trial was “too short for us to detect an effect on survival,” Dr. Paganoni said in an interview. Most of the participants who completed the trial elected to enroll in an open-label extension study and receive AMX0035 long-term. “This is important because it will teach us about the impact of AMX0035 on survival,” said Dr. Paganoni.

Interim data from the ongoing open-label extension study are being submitted to a peer-reviewed journal shortly and will be published in the coming months.
 

A cause for hope

“There has been understandable frustration with the slow pace of development of therapy for ALS,” Michael Benatar, MD, PhD, University of Miami, and Michael McDermott, PhD, University of Rochester (N.Y.), said in an accompanying editorial.

“Despite dozens of trials, few pharmacologic agents have emerged that affect functional decline or survival – and all only modestly so. Although the effects of sodium phenylbutyrate–taurursodiol are similarly modest, the incremental gains that they provide in the battle against ALS are a cause for hope,” they wrote.

They caution, however, that this study was enriched for patients with more rapidly progressive disease, which “raises questions about generalizability to the broader population of patients with ALS.

“Although the patients who were enrolled in the trial may not be biologically different from the broader population of patients with ALS, the magnitude of therapeutic effect may be smaller in the latter,” Dr. Benatar and Dr. McDermott noted.

They said that in light of “residual questions about efficacy and the ability of patients to continue taking the drug,” they agree with the authors’ conclusion that “longer and larger trials are needed to evaluate the efficacy and safety of sodium phenylbutyrate–taurursodiol in persons with ALS.”

Given these “tantalizing preliminary data,” Dr. Benatar and Dr. McDermott said they look forward to “a confirmatory phase 3 trial.” 

The study was supported by Amylyx Pharmaceuticals, the ALS Finding a Cure Foundation, and the ALS Association. Dr. Paganoni has received grants from Revalesio, Ra Pharma, Biohaven, Clene, and Prilenia. A complete list of disclosures for authors and editorialists is available with the original article.

A version of this article originally appeared on Medscape.com.

Two plasma biomarkers were notably associated with when athletes return to action after concussions, according to a new study of collegiate athletes and recovery time. “Although preliminary, the current results highlight the potential role of biomarkers in tracking neuronal recovery, which may be associated with duration of [return to sport],” wrote Cassandra L. Pattinson, PhD, of the University of Queensland, Brisbane, Australia, and the National Institutes of Health, Bethesda, Md., along with coauthors. The study was published in JAMA Network Open.

To determine if three specific blood biomarkers – total tau protein, glial fibrillary acidic protein (GFAP), and neurofilament light chain protein (NfL) – can help predict when athletes should return from sports-related concussions, a multicenter, prospective diagnostic study was launched and led by the Advanced Research Core (ARC) of the Concussion Assessment, Research, and Education (CARE) Consortium. The consortium is a joint effort of the National Collegiate Athletics Association (NCAA) and the U.S. Department of Defense.

From among the CARE ARC database, researchers evaluated 127 eligible student athletes who had experienced a sports-related concussion, underwent clinical testing and blood collection before and after their injuries, and returned to their sports. Their average age was 18.9 years old, 76% were men, and 65% were White. Biomarker levels were measured from nonfasting blood samples via ultrasensitive single molecule array technology. As current NCAA guidelines indicate that most athletes will be asymptomatic roughly 2 weeks after a concussion, the study used 14 days as a cutoff period.

Among the 127 athletes, the median return-to-sport time was 14 days; 65 returned to their sports in less than 14 days while 62 returned to their sports in 14 days or more. According to the study’s linear mixed models, athletes with a return-to-sport time of 14 days or longer had significantly higher total tau levels at 24-48 hours post injury (mean difference –0.51 pg/mL, 95% confidence interval, –0.88 to –0.14; P  = .008) and when symptoms had resolved (mean difference –0.71 pg/mL, 95% CI, –1.09 to –0.34; P < .001) compared with athletes with a return-to-sport time of less than 14 days. Athletes who returned in 14 days or more also had comparatively lower levels of GFAP postinjury than did those who returned in under 14 days (4.39 pg/mL versus 4.72 pg/mL; P = .04).
 

Preliminary steps toward an appropriate point-of-care test

“This particular study is one of several emerging studies on what these biomarkers look like,” Brian W. Hainline, MD, chief medical officer of the NCAA, said in an interview. “It’s all still very preliminary – you couldn’t make policy changes based on what we have – but the data is accumulating. Ultimately, we should be able to perform a multivariate analysis of all the different objective biomarkers, looking at repetitive head impact exposure, looking at imaging, looking at these blood-based biomarkers. Then you can say, ‘OK, what can we do? Can we actually predict recovery, who is likely or less likely to do well?’ ”

“It’s not realistic to be taking blood samples all the time,” said Dr. Hainline, who was not involved in the study. “Another goal, once we know which biomarkers are valuable, is to convert to a point-of-care test. You get a finger prick or even a salivary test and we get the result immediately; that’s the direction that all of this is heading. But first, we have to lay out the groundwork. We envision a day, in the not too distant future, where we can get this information much more quickly.”

The authors acknowledged their study’s limitations, including an inability to standardize the time of biomarker collection and the fact that they analyzed a “relatively small number of athletes” who met their specific criteria. That said, they emphasized that their work is based on “the largest prospective sample of sports-related concussions in athletes to date” and that they “anticipate that we will be able to continue to gather a more representative sample” in the future to better generalize to the larger collegiate community.

The study was supported by the Grand Alliance Concussion Assessment, Research, and Education Consortium, which was funded in part by the NCAA and the Department of Defense. The authors disclosed receiving grants and travel reimbursements from – or working as advisers or consultants for – various organizations, college programs, and sports leagues.

SOURCE: Pattinson CL, et al. JAMA Netw Open. 2020 Aug 27. doi: 10.1001/jamanetworkopen.2020.13191.

Two plasma biomarkers were notably associated with when athletes return to action after concussions, according to a new study of collegiate athletes and recovery time. “Although preliminary, the current results highlight the potential role of biomarkers in tracking neuronal recovery, which may be associated with duration of [return to sport],” wrote Cassandra L. Pattinson, PhD, of the University of Queensland, Brisbane, Australia, and the National Institutes of Health, Bethesda, Md., along with coauthors. The study was published in JAMA Network Open.

To determine if three specific blood biomarkers – total tau protein, glial fibrillary acidic protein (GFAP), and neurofilament light chain protein (NfL) – can help predict when athletes should return from sports-related concussions, a multicenter, prospective diagnostic study was launched and led by the Advanced Research Core (ARC) of the Concussion Assessment, Research, and Education (CARE) Consortium. The consortium is a joint effort of the National Collegiate Athletics Association (NCAA) and the U.S. Department of Defense.

From among the CARE ARC database, researchers evaluated 127 eligible student athletes who had experienced a sports-related concussion, underwent clinical testing and blood collection before and after their injuries, and returned to their sports. Their average age was 18.9 years old, 76% were men, and 65% were White. Biomarker levels were measured from nonfasting blood samples via ultrasensitive single molecule array technology. As current NCAA guidelines indicate that most athletes will be asymptomatic roughly 2 weeks after a concussion, the study used 14 days as a cutoff period.

Among the 127 athletes, the median return-to-sport time was 14 days; 65 returned to their sports in less than 14 days while 62 returned to their sports in 14 days or more. According to the study’s linear mixed models, athletes with a return-to-sport time of 14 days or longer had significantly higher total tau levels at 24-48 hours post injury (mean difference –0.51 pg/mL, 95% confidence interval, –0.88 to –0.14; P  = .008) and when symptoms had resolved (mean difference –0.71 pg/mL, 95% CI, –1.09 to –0.34; P < .001) compared with athletes with a return-to-sport time of less than 14 days. Athletes who returned in 14 days or more also had comparatively lower levels of GFAP postinjury than did those who returned in under 14 days (4.39 pg/mL versus 4.72 pg/mL; P = .04).
 

Preliminary steps toward an appropriate point-of-care test

“This particular study is one of several emerging studies on what these biomarkers look like,” Brian W. Hainline, MD, chief medical officer of the NCAA, said in an interview. “It’s all still very preliminary – you couldn’t make policy changes based on what we have – but the data is accumulating. Ultimately, we should be able to perform a multivariate analysis of all the different objective biomarkers, looking at repetitive head impact exposure, looking at imaging, looking at these blood-based biomarkers. Then you can say, ‘OK, what can we do? Can we actually predict recovery, who is likely or less likely to do well?’ ”

“It’s not realistic to be taking blood samples all the time,” said Dr. Hainline, who was not involved in the study. “Another goal, once we know which biomarkers are valuable, is to convert to a point-of-care test. You get a finger prick or even a salivary test and we get the result immediately; that’s the direction that all of this is heading. But first, we have to lay out the groundwork. We envision a day, in the not too distant future, where we can get this information much more quickly.”

The authors acknowledged their study’s limitations, including an inability to standardize the time of biomarker collection and the fact that they analyzed a “relatively small number of athletes” who met their specific criteria. That said, they emphasized that their work is based on “the largest prospective sample of sports-related concussions in athletes to date” and that they “anticipate that we will be able to continue to gather a more representative sample” in the future to better generalize to the larger collegiate community.

The study was supported by the Grand Alliance Concussion Assessment, Research, and Education Consortium, which was funded in part by the NCAA and the Department of Defense. The authors disclosed receiving grants and travel reimbursements from – or working as advisers or consultants for – various organizations, college programs, and sports leagues.

SOURCE: Pattinson CL, et al. JAMA Netw Open. 2020 Aug 27. doi: 10.1001/jamanetworkopen.2020.13191.

Two plasma biomarkers were notably associated with when athletes return to action after concussions, according to a new study of collegiate athletes and recovery time. “Although preliminary, the current results highlight the potential role of biomarkers in tracking neuronal recovery, which may be associated with duration of [return to sport],” wrote Cassandra L. Pattinson, PhD, of the University of Queensland, Brisbane, Australia, and the National Institutes of Health, Bethesda, Md., along with coauthors. The study was published in JAMA Network Open.

To determine if three specific blood biomarkers – total tau protein, glial fibrillary acidic protein (GFAP), and neurofilament light chain protein (NfL) – can help predict when athletes should return from sports-related concussions, a multicenter, prospective diagnostic study was launched and led by the Advanced Research Core (ARC) of the Concussion Assessment, Research, and Education (CARE) Consortium. The consortium is a joint effort of the National Collegiate Athletics Association (NCAA) and the U.S. Department of Defense.

From among the CARE ARC database, researchers evaluated 127 eligible student athletes who had experienced a sports-related concussion, underwent clinical testing and blood collection before and after their injuries, and returned to their sports. Their average age was 18.9 years old, 76% were men, and 65% were White. Biomarker levels were measured from nonfasting blood samples via ultrasensitive single molecule array technology. As current NCAA guidelines indicate that most athletes will be asymptomatic roughly 2 weeks after a concussion, the study used 14 days as a cutoff period.

Among the 127 athletes, the median return-to-sport time was 14 days; 65 returned to their sports in less than 14 days while 62 returned to their sports in 14 days or more. According to the study’s linear mixed models, athletes with a return-to-sport time of 14 days or longer had significantly higher total tau levels at 24-48 hours post injury (mean difference –0.51 pg/mL, 95% confidence interval, –0.88 to –0.14; P  = .008) and when symptoms had resolved (mean difference –0.71 pg/mL, 95% CI, –1.09 to –0.34; P < .001) compared with athletes with a return-to-sport time of less than 14 days. Athletes who returned in 14 days or more also had comparatively lower levels of GFAP postinjury than did those who returned in under 14 days (4.39 pg/mL versus 4.72 pg/mL; P = .04).
 

Preliminary steps toward an appropriate point-of-care test

“This particular study is one of several emerging studies on what these biomarkers look like,” Brian W. Hainline, MD, chief medical officer of the NCAA, said in an interview. “It’s all still very preliminary – you couldn’t make policy changes based on what we have – but the data is accumulating. Ultimately, we should be able to perform a multivariate analysis of all the different objective biomarkers, looking at repetitive head impact exposure, looking at imaging, looking at these blood-based biomarkers. Then you can say, ‘OK, what can we do? Can we actually predict recovery, who is likely or less likely to do well?’ ”

“It’s not realistic to be taking blood samples all the time,” said Dr. Hainline, who was not involved in the study. “Another goal, once we know which biomarkers are valuable, is to convert to a point-of-care test. You get a finger prick or even a salivary test and we get the result immediately; that’s the direction that all of this is heading. But first, we have to lay out the groundwork. We envision a day, in the not too distant future, where we can get this information much more quickly.”

The authors acknowledged their study’s limitations, including an inability to standardize the time of biomarker collection and the fact that they analyzed a “relatively small number of athletes” who met their specific criteria. That said, they emphasized that their work is based on “the largest prospective sample of sports-related concussions in athletes to date” and that they “anticipate that we will be able to continue to gather a more representative sample” in the future to better generalize to the larger collegiate community.

The study was supported by the Grand Alliance Concussion Assessment, Research, and Education Consortium, which was funded in part by the NCAA and the Department of Defense. The authors disclosed receiving grants and travel reimbursements from – or working as advisers or consultants for – various organizations, college programs, and sports leagues.

SOURCE: Pattinson CL, et al. JAMA Netw Open. 2020 Aug 27. doi: 10.1001/jamanetworkopen.2020.13191.

The mortality burden associated with dementia may be 2.7 times greater than estimated, according to an analysis of a prospective cohort study. This burden may be greatest among non-Hispanic black older adults, compared with Hispanic and non-Hispanic whites. This burden also is significantly greater among people with less than a high school education, compared with those with a college education.

The study results underscore the importance of broadening access to population-based interventions that focus on dementia prevention and care, the investigators wrote. “Future research could examine the extent to which deaths attributable to dementia and underestimation of dementia as an underlying cause of death on death certificates might have changed over time,” wrote Andrew C. Stokes, PhD, assistant professor of global health at the Boston University School of Public Health, and colleagues.

The study was published online Aug. 24 in JAMA Neurology.

In 2019, approximately 5.6 million adults in the United States who were aged 65 years or older had Alzheimer’s disease, vascular dementia, or mixed-cause dementia. A further 18.8% of Americans in this age group had cognitive impairment without dementia (CIND). About one third of patients with CIND may develop Alzheimer’s disease or related dementias (ADRD) within 5 years.

Research suggests that medical examiners significantly underreport ADRD on death certificates. One community-based study, for example, found that only 25% of deaths in patients with dementia had Alzheimer’s disease listed on the death certificates. Other research found that deaths in patients with dementia were often coded using more proximate causes, such as cardiovascular disease, sepsis, and pneumonia.
 

Health and retirement study

Dr. Stokes and colleagues examined data from the Health and Retirement Study (HRS) to evaluate the association of dementia and CIND with all-cause mortality. The HRS is a longitudinal cohort study of adults older than 50 years who live in the community. Its sample is nationally representative. The HRS investigators also initiated the Aging, Demographics, and Memory study to develop a procedure for assessing cognitive status in the HRS sample.

In their study, Dr. Stokes and colleagues included adults who had been sampled in the 2000 wave of HRS. They focused on participants between ages 70 and 99 years at baseline, and their final sample included 7,342 older adults. To identify dementia status, the researchers used the Langa–Weir score cutoff, which is based on tests of immediate and delayed recall of 10 words, a serial 7-second task, and a backward counting task. They also classified dementia status using the Herzog–Wallace, Wu, Hurd, and modified Hurd algorithms.

At baseline, the researchers measured age, sex, race or ethnicity, educational attainment, smoking status, self-reported disease diagnoses, and U.S. Census division as covariates. The National Center for Health Statistics linked HRS data with National Death Index records. These linked records include underlying cause of death and any mention of a condition or cause of death on the death certificate. The researchers compared the percentage of deaths attributable to ADRD according to a population attributable fraction estimate with the proportion of dementia-related deaths according to underlying causes and with any mention of dementia on death certificates.

The sample of 7,342 older adults included 4,348 (60.3%) women. Data for 1,030 (13.4%) people were reported by proxy. At baseline, most participants (64.0%) were between ages 70 and 79 years, 31% were between ages 80 and 89, and 5% were between ages 90 and 99 years. The prevalence of dementia in the complete sample was 14.3%, and the prevalence of CIND was 24.7%. The prevalence of dementia (22.4%) and CIND (29.3%) was higher among decedents than among the full population.

The hazard ratio (HR) for mortality was 2.53 among participants with dementia and 1.53 among patients with CIND. Although 13.6% of deaths were attributable to dementia, the proportion of deaths assigned to dementia as an underlying cause on death certificates was 5.0%. This discrepancy suggests that dementia is underreported by more than a factor of 2.7.

The mortality burden of dementia was 24.7% in non-Hispanic black older adults, 20.7% in Hispanic white participants, and 12.2% in non-Hispanic white participants. In addition, the mortality burden of dementia was significantly greater among participants with less than a high school education (16.2%) than among participants with a college education (9.8%).

The degree to which the underlying cause of death underestimated the mortality burden of dementia varied by sociodemographic characteristics, health status, and geography. The burden was underestimated by a factor of 7.1 among non-Hispanic black participants, a factor of 4.1 among Hispanic participants, and a factor of 2.3 among non-Hispanic white participants. The burden was underestimated by a factor of 3.5 in men and a factor of 2.4 in women. In addition, the burden was underestimated by a factor of 3.0 among participants with less than a high school education, by a factor of 2.3 among participants with a high school education, by a factor of 1.9 in participants with some college, and by a factor of 2.5 among participants with a college or higher education.

One of the study’s strengths was its population attributable fraction analysis, which reduced the risk of overestimating the mortality burden of dementia, Dr. Stokes and colleagues wrote. Examining CIND is valuable because of its high prevalence and consequent influence on outcomes in the population, even though CIND is associated with a lower mortality risk, they added. Nevertheless, the investigators were unable to assess mortality for dementia subtypes, and the classifications of dementia status and CIND may be subject to measurement error.
 

Underestimation is systematic

“This study is eye-opening in that it highlights the systematic underestimation of deaths attributable to dementia,” said Costantino Iadecola, MD, Anne Parrish Titzell professor of neurology and director and chair of the Feil Family Brain and Mind Research Institute at Weill Cornell Medicine in New York. The study’s main strength is that it is nationally representative, but the data must be confirmed in a larger population, he added.

The results will clarify the effect of dementia on mortality for neurologists, and geriatricians should be made aware of them, said Dr. Iadecola. “These data should be valuable to rationalize public health efforts and related funding decisions concerning research and community support.”

Further research could determine the mortality of dementia subgroups, “especially dementias linked to vascular factors in which prevention may be effective,” said Dr. Iadecola. “In the older population, vascular factors may play a more preeminent role, and it may help focus preventive approaches.”

The study was supported by a grant from the National Institute on Aging. Dr. Stokes received grants from Ethicon that were unrelated to this study. Dr. Iadecola serves on the scientific advisory board of Broadview Venture.

egreb@mdedge.com

SOURCE: Stokes AC et al. JAMA Neurol. 2020 Aug 24. doi: 10.1001/jamaneurol.2020.2831.

The mortality burden associated with dementia may be 2.7 times greater than estimated, according to an analysis of a prospective cohort study. This burden may be greatest among non-Hispanic black older adults, compared with Hispanic and non-Hispanic whites. This burden also is significantly greater among people with less than a high school education, compared with those with a college education.

The study results underscore the importance of broadening access to population-based interventions that focus on dementia prevention and care, the investigators wrote. “Future research could examine the extent to which deaths attributable to dementia and underestimation of dementia as an underlying cause of death on death certificates might have changed over time,” wrote Andrew C. Stokes, PhD, assistant professor of global health at the Boston University School of Public Health, and colleagues.

The study was published online Aug. 24 in JAMA Neurology.

In 2019, approximately 5.6 million adults in the United States who were aged 65 years or older had Alzheimer’s disease, vascular dementia, or mixed-cause dementia. A further 18.8% of Americans in this age group had cognitive impairment without dementia (CIND). About one third of patients with CIND may develop Alzheimer’s disease or related dementias (ADRD) within 5 years.

Research suggests that medical examiners significantly underreport ADRD on death certificates. One community-based study, for example, found that only 25% of deaths in patients with dementia had Alzheimer’s disease listed on the death certificates. Other research found that deaths in patients with dementia were often coded using more proximate causes, such as cardiovascular disease, sepsis, and pneumonia.
 

Health and retirement study

Dr. Stokes and colleagues examined data from the Health and Retirement Study (HRS) to evaluate the association of dementia and CIND with all-cause mortality. The HRS is a longitudinal cohort study of adults older than 50 years who live in the community. Its sample is nationally representative. The HRS investigators also initiated the Aging, Demographics, and Memory study to develop a procedure for assessing cognitive status in the HRS sample.

In their study, Dr. Stokes and colleagues included adults who had been sampled in the 2000 wave of HRS. They focused on participants between ages 70 and 99 years at baseline, and their final sample included 7,342 older adults. To identify dementia status, the researchers used the Langa–Weir score cutoff, which is based on tests of immediate and delayed recall of 10 words, a serial 7-second task, and a backward counting task. They also classified dementia status using the Herzog–Wallace, Wu, Hurd, and modified Hurd algorithms.

At baseline, the researchers measured age, sex, race or ethnicity, educational attainment, smoking status, self-reported disease diagnoses, and U.S. Census division as covariates. The National Center for Health Statistics linked HRS data with National Death Index records. These linked records include underlying cause of death and any mention of a condition or cause of death on the death certificate. The researchers compared the percentage of deaths attributable to ADRD according to a population attributable fraction estimate with the proportion of dementia-related deaths according to underlying causes and with any mention of dementia on death certificates.

The sample of 7,342 older adults included 4,348 (60.3%) women. Data for 1,030 (13.4%) people were reported by proxy. At baseline, most participants (64.0%) were between ages 70 and 79 years, 31% were between ages 80 and 89, and 5% were between ages 90 and 99 years. The prevalence of dementia in the complete sample was 14.3%, and the prevalence of CIND was 24.7%. The prevalence of dementia (22.4%) and CIND (29.3%) was higher among decedents than among the full population.

The hazard ratio (HR) for mortality was 2.53 among participants with dementia and 1.53 among patients with CIND. Although 13.6% of deaths were attributable to dementia, the proportion of deaths assigned to dementia as an underlying cause on death certificates was 5.0%. This discrepancy suggests that dementia is underreported by more than a factor of 2.7.

The mortality burden of dementia was 24.7% in non-Hispanic black older adults, 20.7% in Hispanic white participants, and 12.2% in non-Hispanic white participants. In addition, the mortality burden of dementia was significantly greater among participants with less than a high school education (16.2%) than among participants with a college education (9.8%).

The degree to which the underlying cause of death underestimated the mortality burden of dementia varied by sociodemographic characteristics, health status, and geography. The burden was underestimated by a factor of 7.1 among non-Hispanic black participants, a factor of 4.1 among Hispanic participants, and a factor of 2.3 among non-Hispanic white participants. The burden was underestimated by a factor of 3.5 in men and a factor of 2.4 in women. In addition, the burden was underestimated by a factor of 3.0 among participants with less than a high school education, by a factor of 2.3 among participants with a high school education, by a factor of 1.9 in participants with some college, and by a factor of 2.5 among participants with a college or higher education.

One of the study’s strengths was its population attributable fraction analysis, which reduced the risk of overestimating the mortality burden of dementia, Dr. Stokes and colleagues wrote. Examining CIND is valuable because of its high prevalence and consequent influence on outcomes in the population, even though CIND is associated with a lower mortality risk, they added. Nevertheless, the investigators were unable to assess mortality for dementia subtypes, and the classifications of dementia status and CIND may be subject to measurement error.
 

Underestimation is systematic

“This study is eye-opening in that it highlights the systematic underestimation of deaths attributable to dementia,” said Costantino Iadecola, MD, Anne Parrish Titzell professor of neurology and director and chair of the Feil Family Brain and Mind Research Institute at Weill Cornell Medicine in New York. The study’s main strength is that it is nationally representative, but the data must be confirmed in a larger population, he added.

The results will clarify the effect of dementia on mortality for neurologists, and geriatricians should be made aware of them, said Dr. Iadecola. “These data should be valuable to rationalize public health efforts and related funding decisions concerning research and community support.”

Further research could determine the mortality of dementia subgroups, “especially dementias linked to vascular factors in which prevention may be effective,” said Dr. Iadecola. “In the older population, vascular factors may play a more preeminent role, and it may help focus preventive approaches.”

The study was supported by a grant from the National Institute on Aging. Dr. Stokes received grants from Ethicon that were unrelated to this study. Dr. Iadecola serves on the scientific advisory board of Broadview Venture.

egreb@mdedge.com

SOURCE: Stokes AC et al. JAMA Neurol. 2020 Aug 24. doi: 10.1001/jamaneurol.2020.2831.

The mortality burden associated with dementia may be 2.7 times greater than estimated, according to an analysis of a prospective cohort study. This burden may be greatest among non-Hispanic black older adults, compared with Hispanic and non-Hispanic whites. This burden also is significantly greater among people with less than a high school education, compared with those with a college education.

The study results underscore the importance of broadening access to population-based interventions that focus on dementia prevention and care, the investigators wrote. “Future research could examine the extent to which deaths attributable to dementia and underestimation of dementia as an underlying cause of death on death certificates might have changed over time,” wrote Andrew C. Stokes, PhD, assistant professor of global health at the Boston University School of Public Health, and colleagues.

The study was published online Aug. 24 in JAMA Neurology.

In 2019, approximately 5.6 million adults in the United States who were aged 65 years or older had Alzheimer’s disease, vascular dementia, or mixed-cause dementia. A further 18.8% of Americans in this age group had cognitive impairment without dementia (CIND). About one third of patients with CIND may develop Alzheimer’s disease or related dementias (ADRD) within 5 years.

Research suggests that medical examiners significantly underreport ADRD on death certificates. One community-based study, for example, found that only 25% of deaths in patients with dementia had Alzheimer’s disease listed on the death certificates. Other research found that deaths in patients with dementia were often coded using more proximate causes, such as cardiovascular disease, sepsis, and pneumonia.
 

Health and retirement study

Dr. Stokes and colleagues examined data from the Health and Retirement Study (HRS) to evaluate the association of dementia and CIND with all-cause mortality. The HRS is a longitudinal cohort study of adults older than 50 years who live in the community. Its sample is nationally representative. The HRS investigators also initiated the Aging, Demographics, and Memory study to develop a procedure for assessing cognitive status in the HRS sample.

In their study, Dr. Stokes and colleagues included adults who had been sampled in the 2000 wave of HRS. They focused on participants between ages 70 and 99 years at baseline, and their final sample included 7,342 older adults. To identify dementia status, the researchers used the Langa–Weir score cutoff, which is based on tests of immediate and delayed recall of 10 words, a serial 7-second task, and a backward counting task. They also classified dementia status using the Herzog–Wallace, Wu, Hurd, and modified Hurd algorithms.

At baseline, the researchers measured age, sex, race or ethnicity, educational attainment, smoking status, self-reported disease diagnoses, and U.S. Census division as covariates. The National Center for Health Statistics linked HRS data with National Death Index records. These linked records include underlying cause of death and any mention of a condition or cause of death on the death certificate. The researchers compared the percentage of deaths attributable to ADRD according to a population attributable fraction estimate with the proportion of dementia-related deaths according to underlying causes and with any mention of dementia on death certificates.

The sample of 7,342 older adults included 4,348 (60.3%) women. Data for 1,030 (13.4%) people were reported by proxy. At baseline, most participants (64.0%) were between ages 70 and 79 years, 31% were between ages 80 and 89, and 5% were between ages 90 and 99 years. The prevalence of dementia in the complete sample was 14.3%, and the prevalence of CIND was 24.7%. The prevalence of dementia (22.4%) and CIND (29.3%) was higher among decedents than among the full population.

The hazard ratio (HR) for mortality was 2.53 among participants with dementia and 1.53 among patients with CIND. Although 13.6% of deaths were attributable to dementia, the proportion of deaths assigned to dementia as an underlying cause on death certificates was 5.0%. This discrepancy suggests that dementia is underreported by more than a factor of 2.7.

The mortality burden of dementia was 24.7% in non-Hispanic black older adults, 20.7% in Hispanic white participants, and 12.2% in non-Hispanic white participants. In addition, the mortality burden of dementia was significantly greater among participants with less than a high school education (16.2%) than among participants with a college education (9.8%).

The degree to which the underlying cause of death underestimated the mortality burden of dementia varied by sociodemographic characteristics, health status, and geography. The burden was underestimated by a factor of 7.1 among non-Hispanic black participants, a factor of 4.1 among Hispanic participants, and a factor of 2.3 among non-Hispanic white participants. The burden was underestimated by a factor of 3.5 in men and a factor of 2.4 in women. In addition, the burden was underestimated by a factor of 3.0 among participants with less than a high school education, by a factor of 2.3 among participants with a high school education, by a factor of 1.9 in participants with some college, and by a factor of 2.5 among participants with a college or higher education.

One of the study’s strengths was its population attributable fraction analysis, which reduced the risk of overestimating the mortality burden of dementia, Dr. Stokes and colleagues wrote. Examining CIND is valuable because of its high prevalence and consequent influence on outcomes in the population, even though CIND is associated with a lower mortality risk, they added. Nevertheless, the investigators were unable to assess mortality for dementia subtypes, and the classifications of dementia status and CIND may be subject to measurement error.
 

Underestimation is systematic

“This study is eye-opening in that it highlights the systematic underestimation of deaths attributable to dementia,” said Costantino Iadecola, MD, Anne Parrish Titzell professor of neurology and director and chair of the Feil Family Brain and Mind Research Institute at Weill Cornell Medicine in New York. The study’s main strength is that it is nationally representative, but the data must be confirmed in a larger population, he added.

The results will clarify the effect of dementia on mortality for neurologists, and geriatricians should be made aware of them, said Dr. Iadecola. “These data should be valuable to rationalize public health efforts and related funding decisions concerning research and community support.”

Further research could determine the mortality of dementia subgroups, “especially dementias linked to vascular factors in which prevention may be effective,” said Dr. Iadecola. “In the older population, vascular factors may play a more preeminent role, and it may help focus preventive approaches.”

The study was supported by a grant from the National Institute on Aging. Dr. Stokes received grants from Ethicon that were unrelated to this study. Dr. Iadecola serves on the scientific advisory board of Broadview Venture.

egreb@mdedge.com

SOURCE: Stokes AC et al. JAMA Neurol. 2020 Aug 24. doi: 10.1001/jamaneurol.2020.2831.

Alzheimer’s disease may have a causal effect on sleep patterns, but disturbed sleep does not appear to cause Alzheimer’s disease, new research suggests.

The causal association between disturbed sleep and Alzheimer’s disease that has been observed in previous studies may have resulted from reverse causation, the researchers noted. The current Mendelian randomization analysis also failed to find a causal relationship between Alzheimer’s disease and major depressive disorder. Future studies should examine the genetic heterogeneity of depression syndromes to test for causal relationships between subtypes of depression with distinct causes and Alzheimer’s disease.

Mendelian randomization compares individuals who have different genetic profiles for a given exposure. “Given that genetic variants are inherited at random, these two groups are comparable, and any differences are not likely to be due to other associated factors,” such as confounding bias, said corresponding author Abbas Dehghan, PhD, reader in cardiometabolic disease epidemiology at Imperial College London. “Moreover, given that genetic information is constant over the lifetime, the chances for reverse causation are small.”

The findings were published online August 19 in Neurology.

Causal questions

Many patients with late-life neurodegenerative disorders such as Alzheimer’s disease have comorbid depression, but whether these two disorders have a causal relationship or common risk factors has been unclear, the investigators noted. Abnormal sleep patterns are symptoms of both depression and Alzheimer’s disease. Abnormal sleep is also associated with cognitive decline and anxiety.

The researchers hypothesized that sleep causally affects major depressive disorder and Alzheimer’s disease but that there is no causal relationship between major depressive disorder and Alzheimer’s disease. They conducted a bidirectional, two-sample Mendelian randomization study to test these hypotheses.

The investigators conducted genomewide association studies (GWASs) using data from the prospective, population-based U.K. Biobank. Sleep phenotypes were measured by self-report or accelerometer. Genetic associations were derived from 403,195 patients for chronotype, 237,627 patients for insomnia, 446,118 people for sleep duration, and 85,670 people for accelerometer-derived phenotypes.

Two binary variables from sleep duration were derived: short sleep (duration of less than 7 hours) and long sleep (duration of 9 or more hours). A sleep episode was defined as a period of at least 5 minutes with a change on the dorsal-ventral axis of less than 5 degrees. The durations of all sleep episodes were added to calculate total sleep duration.

Major depressive disorder was diagnosed clinically in accordance with DSM-IV criteria. Genetic associations were derived from 9,240 case patients and 9,519 control participants. Alzheimer’s disease was diagnosed on the basis of physician examination or autopsy results. Genetic associations were obtained from a meta-analysis of GWAS on participants of European ancestry in the International Genomics of Alzheimer’s Project, which included 21,982 case patients and 41,944 control participants.

More risk factor research needed

Results showed no causal relationships between sleep-related phenotypes and major depressive disorder in either direction. Causal relationships between major depressive disorder and Alzheimer’s disease were found in both directions, but neither was statistically significant.

A genetically higher risk for Alzheimer’s disease was associated with being a “morning person,” being at decreased risk for insomnia, having shorter sleep duration on self-report and accelerometer, having decreased likelihood of reporting long sleep, having an earlier timing of the least active 5 hours, and having a smaller number of sleep episodes. However, no analysis supported a causal effect of sleep-related phenotypes on risk for Alzheimer’s disease.

Because APOE4 can influence disease processes that may contribute to Alzheimer’s disease risk, the investigators also conducted a sensitivity analysis that excluded APOE single-nucleotide polymorphisms. In this analysis, the causal associations of Alzheimer’s disease with self-reported and accelerometer-based sleep duration were not significant. The sensitivity analysis did support the other causal associations between Alzheimer’s disease and sleep phenotypes, however.

The causal associations between major depressive disorder and Alzheimer’s disease observed in other studies may have been the result of confounding, and the participants may have had other associated characteristics that put them at risk for the disease, said Dr. Dehghan. Furthermore, the previous studies considered various sleep phenotypes together, whereas in the current study, the investigators examined them separately.

The results suggest that preclinical and clinical Alzheimer’s disease may affect sleep phenotypes differently. Sleep management thus could be an important approach to improving quality of life for patients with Alzheimer’s disease, the researchers wrote.

“Our study indicates that depression and sleep disorders are not likely to be a causal factor for Alzheimer’s disease,” Dr. Dehghan said. “We need to search for other risk factors for the prevention of Alzheimer’s disease.”

Several strengths, lacks details

Walter A. Kukull, PhD, professor of epidemiology and director of the National Alzheimer’s Coordinating Center at the University of Washington, Seattle, noted that the investigators appear to have implemented their chosen methods of causal association analysis well. “They attempted to examine the direction of the causal arrow for risk factors … and that is a step usually not well examined in other studies.”

He added that the collection of objective measures, such as of sleep, is another strength of the study.

However, “the common weakness of the basic GWAS sample is that clinical symptomatology determined Alzheimer’s disease diagnosis. Thus, asymptomatic or very mildly symptomatic persons with Alzheimer’s disease pathology in their brains were likely included among normal controls,” said Dr. Kukull, who was not involved with the research.

Because of an apparent lack of biomarker data, patients who had been diagnosed with Alzheimer’s disease may in fact have had a different form of dementia. Given the nature of their data, the investigators could have done little to compensate for these possibilities, Dr. Kukull added. In addition, the article lacks details that would improve the interpretation of the results.

“Timing is everything with regard to potential associations between risk factor and outcome,” Dr. Kukull said. “With the exceptions of genes, it would be nice to know more about the timing of risk factors’ onset and Alzheimer’s disease onset.”

Still, the results indicate potential areas of future study, he noted. “Primarily, further research must address the question of pathological onset of disease and misclassification of diagnosis in both cases and controls due to lack of biomarker-confirmed diagnosis. Then research can also struggle with the timing of potential risk factors with respect to disease.”

The study was funded by the U.K. Dementia Research Institute. Dr. Dehghan and Dr. Kukull reported no relevant financial relationships.

A version of this article originally appeared on Medscape.com.

Alzheimer’s disease may have a causal effect on sleep patterns, but disturbed sleep does not appear to cause Alzheimer’s disease, new research suggests.

The causal association between disturbed sleep and Alzheimer’s disease that has been observed in previous studies may have resulted from reverse causation, the researchers noted. The current Mendelian randomization analysis also failed to find a causal relationship between Alzheimer’s disease and major depressive disorder. Future studies should examine the genetic heterogeneity of depression syndromes to test for causal relationships between subtypes of depression with distinct causes and Alzheimer’s disease.

Mendelian randomization compares individuals who have different genetic profiles for a given exposure. “Given that genetic variants are inherited at random, these two groups are comparable, and any differences are not likely to be due to other associated factors,” such as confounding bias, said corresponding author Abbas Dehghan, PhD, reader in cardiometabolic disease epidemiology at Imperial College London. “Moreover, given that genetic information is constant over the lifetime, the chances for reverse causation are small.”

The findings were published online August 19 in Neurology.

Causal questions

Many patients with late-life neurodegenerative disorders such as Alzheimer’s disease have comorbid depression, but whether these two disorders have a causal relationship or common risk factors has been unclear, the investigators noted. Abnormal sleep patterns are symptoms of both depression and Alzheimer’s disease. Abnormal sleep is also associated with cognitive decline and anxiety.

The researchers hypothesized that sleep causally affects major depressive disorder and Alzheimer’s disease but that there is no causal relationship between major depressive disorder and Alzheimer’s disease. They conducted a bidirectional, two-sample Mendelian randomization study to test these hypotheses.

The investigators conducted genomewide association studies (GWASs) using data from the prospective, population-based U.K. Biobank. Sleep phenotypes were measured by self-report or accelerometer. Genetic associations were derived from 403,195 patients for chronotype, 237,627 patients for insomnia, 446,118 people for sleep duration, and 85,670 people for accelerometer-derived phenotypes.

Two binary variables from sleep duration were derived: short sleep (duration of less than 7 hours) and long sleep (duration of 9 or more hours). A sleep episode was defined as a period of at least 5 minutes with a change on the dorsal-ventral axis of less than 5 degrees. The durations of all sleep episodes were added to calculate total sleep duration.

Major depressive disorder was diagnosed clinically in accordance with DSM-IV criteria. Genetic associations were derived from 9,240 case patients and 9,519 control participants. Alzheimer’s disease was diagnosed on the basis of physician examination or autopsy results. Genetic associations were obtained from a meta-analysis of GWAS on participants of European ancestry in the International Genomics of Alzheimer’s Project, which included 21,982 case patients and 41,944 control participants.

More risk factor research needed

Results showed no causal relationships between sleep-related phenotypes and major depressive disorder in either direction. Causal relationships between major depressive disorder and Alzheimer’s disease were found in both directions, but neither was statistically significant.

A genetically higher risk for Alzheimer’s disease was associated with being a “morning person,” being at decreased risk for insomnia, having shorter sleep duration on self-report and accelerometer, having decreased likelihood of reporting long sleep, having an earlier timing of the least active 5 hours, and having a smaller number of sleep episodes. However, no analysis supported a causal effect of sleep-related phenotypes on risk for Alzheimer’s disease.

Because APOE4 can influence disease processes that may contribute to Alzheimer’s disease risk, the investigators also conducted a sensitivity analysis that excluded APOE single-nucleotide polymorphisms. In this analysis, the causal associations of Alzheimer’s disease with self-reported and accelerometer-based sleep duration were not significant. The sensitivity analysis did support the other causal associations between Alzheimer’s disease and sleep phenotypes, however.

The causal associations between major depressive disorder and Alzheimer’s disease observed in other studies may have been the result of confounding, and the participants may have had other associated characteristics that put them at risk for the disease, said Dr. Dehghan. Furthermore, the previous studies considered various sleep phenotypes together, whereas in the current study, the investigators examined them separately.

The results suggest that preclinical and clinical Alzheimer’s disease may affect sleep phenotypes differently. Sleep management thus could be an important approach to improving quality of life for patients with Alzheimer’s disease, the researchers wrote.

“Our study indicates that depression and sleep disorders are not likely to be a causal factor for Alzheimer’s disease,” Dr. Dehghan said. “We need to search for other risk factors for the prevention of Alzheimer’s disease.”

Several strengths, lacks details

Walter A. Kukull, PhD, professor of epidemiology and director of the National Alzheimer’s Coordinating Center at the University of Washington, Seattle, noted that the investigators appear to have implemented their chosen methods of causal association analysis well. “They attempted to examine the direction of the causal arrow for risk factors … and that is a step usually not well examined in other studies.”

He added that the collection of objective measures, such as of sleep, is another strength of the study.

However, “the common weakness of the basic GWAS sample is that clinical symptomatology determined Alzheimer’s disease diagnosis. Thus, asymptomatic or very mildly symptomatic persons with Alzheimer’s disease pathology in their brains were likely included among normal controls,” said Dr. Kukull, who was not involved with the research.

Because of an apparent lack of biomarker data, patients who had been diagnosed with Alzheimer’s disease may in fact have had a different form of dementia. Given the nature of their data, the investigators could have done little to compensate for these possibilities, Dr. Kukull added. In addition, the article lacks details that would improve the interpretation of the results.

“Timing is everything with regard to potential associations between risk factor and outcome,” Dr. Kukull said. “With the exceptions of genes, it would be nice to know more about the timing of risk factors’ onset and Alzheimer’s disease onset.”

Still, the results indicate potential areas of future study, he noted. “Primarily, further research must address the question of pathological onset of disease and misclassification of diagnosis in both cases and controls due to lack of biomarker-confirmed diagnosis. Then research can also struggle with the timing of potential risk factors with respect to disease.”

The study was funded by the U.K. Dementia Research Institute. Dr. Dehghan and Dr. Kukull reported no relevant financial relationships.

A version of this article originally appeared on Medscape.com.

Alzheimer’s disease may have a causal effect on sleep patterns, but disturbed sleep does not appear to cause Alzheimer’s disease, new research suggests.

The causal association between disturbed sleep and Alzheimer’s disease that has been observed in previous studies may have resulted from reverse causation, the researchers noted. The current Mendelian randomization analysis also failed to find a causal relationship between Alzheimer’s disease and major depressive disorder. Future studies should examine the genetic heterogeneity of depression syndromes to test for causal relationships between subtypes of depression with distinct causes and Alzheimer’s disease.

Mendelian randomization compares individuals who have different genetic profiles for a given exposure. “Given that genetic variants are inherited at random, these two groups are comparable, and any differences are not likely to be due to other associated factors,” such as confounding bias, said corresponding author Abbas Dehghan, PhD, reader in cardiometabolic disease epidemiology at Imperial College London. “Moreover, given that genetic information is constant over the lifetime, the chances for reverse causation are small.”

The findings were published online August 19 in Neurology.

Causal questions

Many patients with late-life neurodegenerative disorders such as Alzheimer’s disease have comorbid depression, but whether these two disorders have a causal relationship or common risk factors has been unclear, the investigators noted. Abnormal sleep patterns are symptoms of both depression and Alzheimer’s disease. Abnormal sleep is also associated with cognitive decline and anxiety.

The researchers hypothesized that sleep causally affects major depressive disorder and Alzheimer’s disease but that there is no causal relationship between major depressive disorder and Alzheimer’s disease. They conducted a bidirectional, two-sample Mendelian randomization study to test these hypotheses.

The investigators conducted genomewide association studies (GWASs) using data from the prospective, population-based U.K. Biobank. Sleep phenotypes were measured by self-report or accelerometer. Genetic associations were derived from 403,195 patients for chronotype, 237,627 patients for insomnia, 446,118 people for sleep duration, and 85,670 people for accelerometer-derived phenotypes.

Two binary variables from sleep duration were derived: short sleep (duration of less than 7 hours) and long sleep (duration of 9 or more hours). A sleep episode was defined as a period of at least 5 minutes with a change on the dorsal-ventral axis of less than 5 degrees. The durations of all sleep episodes were added to calculate total sleep duration.

Major depressive disorder was diagnosed clinically in accordance with DSM-IV criteria. Genetic associations were derived from 9,240 case patients and 9,519 control participants. Alzheimer’s disease was diagnosed on the basis of physician examination or autopsy results. Genetic associations were obtained from a meta-analysis of GWAS on participants of European ancestry in the International Genomics of Alzheimer’s Project, which included 21,982 case patients and 41,944 control participants.

More risk factor research needed

Results showed no causal relationships between sleep-related phenotypes and major depressive disorder in either direction. Causal relationships between major depressive disorder and Alzheimer’s disease were found in both directions, but neither was statistically significant.

A genetically higher risk for Alzheimer’s disease was associated with being a “morning person,” being at decreased risk for insomnia, having shorter sleep duration on self-report and accelerometer, having decreased likelihood of reporting long sleep, having an earlier timing of the least active 5 hours, and having a smaller number of sleep episodes. However, no analysis supported a causal effect of sleep-related phenotypes on risk for Alzheimer’s disease.

Because APOE4 can influence disease processes that may contribute to Alzheimer’s disease risk, the investigators also conducted a sensitivity analysis that excluded APOE single-nucleotide polymorphisms. In this analysis, the causal associations of Alzheimer’s disease with self-reported and accelerometer-based sleep duration were not significant. The sensitivity analysis did support the other causal associations between Alzheimer’s disease and sleep phenotypes, however.

The causal associations between major depressive disorder and Alzheimer’s disease observed in other studies may have been the result of confounding, and the participants may have had other associated characteristics that put them at risk for the disease, said Dr. Dehghan. Furthermore, the previous studies considered various sleep phenotypes together, whereas in the current study, the investigators examined them separately.

The results suggest that preclinical and clinical Alzheimer’s disease may affect sleep phenotypes differently. Sleep management thus could be an important approach to improving quality of life for patients with Alzheimer’s disease, the researchers wrote.

“Our study indicates that depression and sleep disorders are not likely to be a causal factor for Alzheimer’s disease,” Dr. Dehghan said. “We need to search for other risk factors for the prevention of Alzheimer’s disease.”

Several strengths, lacks details

Walter A. Kukull, PhD, professor of epidemiology and director of the National Alzheimer’s Coordinating Center at the University of Washington, Seattle, noted that the investigators appear to have implemented their chosen methods of causal association analysis well. “They attempted to examine the direction of the causal arrow for risk factors … and that is a step usually not well examined in other studies.”

He added that the collection of objective measures, such as of sleep, is another strength of the study.

However, “the common weakness of the basic GWAS sample is that clinical symptomatology determined Alzheimer’s disease diagnosis. Thus, asymptomatic or very mildly symptomatic persons with Alzheimer’s disease pathology in their brains were likely included among normal controls,” said Dr. Kukull, who was not involved with the research.

Because of an apparent lack of biomarker data, patients who had been diagnosed with Alzheimer’s disease may in fact have had a different form of dementia. Given the nature of their data, the investigators could have done little to compensate for these possibilities, Dr. Kukull added. In addition, the article lacks details that would improve the interpretation of the results.

“Timing is everything with regard to potential associations between risk factor and outcome,” Dr. Kukull said. “With the exceptions of genes, it would be nice to know more about the timing of risk factors’ onset and Alzheimer’s disease onset.”

Still, the results indicate potential areas of future study, he noted. “Primarily, further research must address the question of pathological onset of disease and misclassification of diagnosis in both cases and controls due to lack of biomarker-confirmed diagnosis. Then research can also struggle with the timing of potential risk factors with respect to disease.”

The study was funded by the U.K. Dementia Research Institute. Dr. Dehghan and Dr. Kukull reported no relevant financial relationships.

A version of this article originally appeared on Medscape.com.

Myasthenia gravis should be added to the growing list of potential neurological sequelae associated with COVID-19, new research suggests. Clinicians from Italy have described what they believe are the first three reported cases of acetylcholine receptor (AChR) antibody-positive myasthenia gravis after COVID-19 infection.

“I think it is possible that there could be many more cases,” said lead author Domenico Restivo, MD, of the Garibaldi Hospital, Catania, Italy. “In fact, myasthenia gravis could be underestimated especially in the course of COVID-19 infection in which a specific muscular weakness is frequently present. For this reason, this association is easy to miss if not top of mind,” Dr. Restivo said.

None of the three patients had previous neurologic or autoimmune disorders. In all three cases, symptoms of myasthenia gravis appeared within 5-7 days after onset of fever caused by SARS-CoV-2 infection. The time from presumed SARS-CoV-2 infection to myasthenia gravis symptoms “is consistent with the time from infection to symptoms in other neurologic disorders triggered by infections,” the investigators reported.

The findings were published online August 10 in Annals of Internal Medicine.
 

First patients

The first patient described in the report was a 64-year-old man who had a fever as high as 39° C (102.2° F) for 4 days. Five days after fever onset, he developed diplopia and muscle fatigue. The patient’s neurologic examination was “unremarkable.” Computed tomography (CT) of the thorax excluded thymoma, and findings on chest radiograph were normal. He tested positive for SARS-CoV-2 on nasopharyngeal swab and real-time reverse transcriptase polymerase chain reaction (RT-PCR).

The patient’s symptoms led the investigators to suspect myasthenia gravis. Repetitive stimulation of the patient’s facial nerve showed a 57% decrement, confirming involvement of the postsynaptic neuromuscular junction. The concentration of AChR antibodies in serum was also elevated (22.8 pmol/L; reference range, <0.4 pmol/L). The patient was treated with pyridostigmine bromide and prednisone and had a response “typical for someone with myasthenia gravis,” the researchers wrote.

The second patient was a 68-year-old man who had a fever as high as 38.8° C (101.8° F) for 7 days. On day 7, he developed muscle fatigue, diplopia, and dysphagia. Findings of a chest CT and neurologic exam were normal. Nasopharyngeal swab and RT-PCR testing for COVID-19 were positive. As with the first patient, myasthenia gravis was suspected because of the patient’s symptoms. Repetitive nerve stimulation revealed a postsynaptic deficit of neuromuscular transmission of the facial (52%) and ulnar (21%) nerves. His serum AChR antibody level was elevated (27.6 pmol/L). The patient improved after one cycle of intravenous immunoglobulin treatment.
 

Possible mechanisms

The third patient was a 71-year-old woman with cough and a fever up to 38.6° C (101.5° F) for 6 days. She initially tested negative for SARS-CoV-2 on nasopharyngeal swab and RT-PCR. Five days after her symptoms began, she developed bilateral ocular ptosis, diplopia, and hypophonia. CT of the thorax excluded thymoma but showed bilateral interstitial pneumonia. On day 6, she developed dysphagia and respiratory failure, and was transferred to the ICU where she received mechanical ventilation.

Repetitive nerve stimulation revealed a postsynaptic deficit of neuromuscular transmission of the ulnar nerve (56%), and her serum AChR antibody level was elevated (35.6 pmol/L). Five days later, a second nasopharyngeal swab test for SARS-CoV-2 was positive. The patient improved following plasmapheresis treatment and was successfully extubated.

The investigators noted that this patient received hydroxychloroquine the day after the onset of neurologic symptoms, but the drug was withdrawn a day later, so they do not believe that it caused the symptoms of myasthenia gravis.

The observations in these three patients are “consistent with reports of other infections that induce autoimmune disorders, as well as with the growing evidence of other neurologic disorders with presumed autoimmune mechanisms after COVID-19 onset,” the researchers wrote.

They offered several possible explanations for the link between COVID-19 and myasthenia gravis. “Antibodies that are directed against SARS-CoV-2 proteins may cross-react with AChR subunits, because the virus has epitopes that are similar to components of the neuromuscular junction; this is known to occur in other neurologic autoimmune disorders after infection. Alternatively, COVID-19 infection may break immunologic self-tolerance,” the investigators wrote.

“The main message for clinicians is that myasthenia gravis, as well as other neurological disorders associated with autoimmunity, could occur in the course of SARS-CoV-2 infection,” Dr. Restivo said. Prompt recognition of the disease “could lead to a drug treatment that limits its evolution as quickly as possible,” he added.
 

An “unmasking”

Commenting on the findings, Anthony Geraci, MD, director of neuromuscular medicine, Northwell Health, Great Neck, N.Y., said these case reports of myasthenia gravis after SARS-CoV-2 infection are “not unique or novel as there has been a long understanding that seropositive [AChR antibody-positive] myasthenia gravis can and is frequently ‘unmasked’ in the setting” of several viral and bacterial infections.

“Antibodies in myasthenia gravis are of a type that take several weeks to develop to measurable levels as in the reported cases by Restivo et al., giving strong support to the notion that subclinical myasthenia gravis can be immunologically upregulated in the setting of viral infection and this is a far more likely explanation of the observed association reported,” added Dr. Geraci, who was not involved with the research.

He noted that, at his institution, “we have also observed ocular myasthenia gravis emerge in patients with SARS-CoV-2 infection, with similar double vision and lid droop, as we have seen similarly in patients with Zika, West Nile, and other viral infections, as well as a multiplicity of bacterial infections.”

“Most of our observed patients have responded to treatment much the same as reported by the three cases from Restivo and colleagues,” Dr.Geraci reported.

The authors of the study disclosed no conflicts of interest.

A version of this article originally appeared on Medscape.com.

Myasthenia gravis should be added to the growing list of potential neurological sequelae associated with COVID-19, new research suggests. Clinicians from Italy have described what they believe are the first three reported cases of acetylcholine receptor (AChR) antibody-positive myasthenia gravis after COVID-19 infection.

“I think it is possible that there could be many more cases,” said lead author Domenico Restivo, MD, of the Garibaldi Hospital, Catania, Italy. “In fact, myasthenia gravis could be underestimated especially in the course of COVID-19 infection in which a specific muscular weakness is frequently present. For this reason, this association is easy to miss if not top of mind,” Dr. Restivo said.

None of the three patients had previous neurologic or autoimmune disorders. In all three cases, symptoms of myasthenia gravis appeared within 5-7 days after onset of fever caused by SARS-CoV-2 infection. The time from presumed SARS-CoV-2 infection to myasthenia gravis symptoms “is consistent with the time from infection to symptoms in other neurologic disorders triggered by infections,” the investigators reported.

The findings were published online August 10 in Annals of Internal Medicine.
 

First patients

The first patient described in the report was a 64-year-old man who had a fever as high as 39° C (102.2° F) for 4 days. Five days after fever onset, he developed diplopia and muscle fatigue. The patient’s neurologic examination was “unremarkable.” Computed tomography (CT) of the thorax excluded thymoma, and findings on chest radiograph were normal. He tested positive for SARS-CoV-2 on nasopharyngeal swab and real-time reverse transcriptase polymerase chain reaction (RT-PCR).

The patient’s symptoms led the investigators to suspect myasthenia gravis. Repetitive stimulation of the patient’s facial nerve showed a 57% decrement, confirming involvement of the postsynaptic neuromuscular junction. The concentration of AChR antibodies in serum was also elevated (22.8 pmol/L; reference range, <0.4 pmol/L). The patient was treated with pyridostigmine bromide and prednisone and had a response “typical for someone with myasthenia gravis,” the researchers wrote.

The second patient was a 68-year-old man who had a fever as high as 38.8° C (101.8° F) for 7 days. On day 7, he developed muscle fatigue, diplopia, and dysphagia. Findings of a chest CT and neurologic exam were normal. Nasopharyngeal swab and RT-PCR testing for COVID-19 were positive. As with the first patient, myasthenia gravis was suspected because of the patient’s symptoms. Repetitive nerve stimulation revealed a postsynaptic deficit of neuromuscular transmission of the facial (52%) and ulnar (21%) nerves. His serum AChR antibody level was elevated (27.6 pmol/L). The patient improved after one cycle of intravenous immunoglobulin treatment.
 

Possible mechanisms

The third patient was a 71-year-old woman with cough and a fever up to 38.6° C (101.5° F) for 6 days. She initially tested negative for SARS-CoV-2 on nasopharyngeal swab and RT-PCR. Five days after her symptoms began, she developed bilateral ocular ptosis, diplopia, and hypophonia. CT of the thorax excluded thymoma but showed bilateral interstitial pneumonia. On day 6, she developed dysphagia and respiratory failure, and was transferred to the ICU where she received mechanical ventilation.

Repetitive nerve stimulation revealed a postsynaptic deficit of neuromuscular transmission of the ulnar nerve (56%), and her serum AChR antibody level was elevated (35.6 pmol/L). Five days later, a second nasopharyngeal swab test for SARS-CoV-2 was positive. The patient improved following plasmapheresis treatment and was successfully extubated.

The investigators noted that this patient received hydroxychloroquine the day after the onset of neurologic symptoms, but the drug was withdrawn a day later, so they do not believe that it caused the symptoms of myasthenia gravis.

The observations in these three patients are “consistent with reports of other infections that induce autoimmune disorders, as well as with the growing evidence of other neurologic disorders with presumed autoimmune mechanisms after COVID-19 onset,” the researchers wrote.

They offered several possible explanations for the link between COVID-19 and myasthenia gravis. “Antibodies that are directed against SARS-CoV-2 proteins may cross-react with AChR subunits, because the virus has epitopes that are similar to components of the neuromuscular junction; this is known to occur in other neurologic autoimmune disorders after infection. Alternatively, COVID-19 infection may break immunologic self-tolerance,” the investigators wrote.

“The main message for clinicians is that myasthenia gravis, as well as other neurological disorders associated with autoimmunity, could occur in the course of SARS-CoV-2 infection,” Dr. Restivo said. Prompt recognition of the disease “could lead to a drug treatment that limits its evolution as quickly as possible,” he added.
 

An “unmasking”

Commenting on the findings, Anthony Geraci, MD, director of neuromuscular medicine, Northwell Health, Great Neck, N.Y., said these case reports of myasthenia gravis after SARS-CoV-2 infection are “not unique or novel as there has been a long understanding that seropositive [AChR antibody-positive] myasthenia gravis can and is frequently ‘unmasked’ in the setting” of several viral and bacterial infections.

“Antibodies in myasthenia gravis are of a type that take several weeks to develop to measurable levels as in the reported cases by Restivo et al., giving strong support to the notion that subclinical myasthenia gravis can be immunologically upregulated in the setting of viral infection and this is a far more likely explanation of the observed association reported,” added Dr. Geraci, who was not involved with the research.

He noted that, at his institution, “we have also observed ocular myasthenia gravis emerge in patients with SARS-CoV-2 infection, with similar double vision and lid droop, as we have seen similarly in patients with Zika, West Nile, and other viral infections, as well as a multiplicity of bacterial infections.”

“Most of our observed patients have responded to treatment much the same as reported by the three cases from Restivo and colleagues,” Dr.Geraci reported.

The authors of the study disclosed no conflicts of interest.

A version of this article originally appeared on Medscape.com.

Myasthenia gravis should be added to the growing list of potential neurological sequelae associated with COVID-19, new research suggests. Clinicians from Italy have described what they believe are the first three reported cases of acetylcholine receptor (AChR) antibody-positive myasthenia gravis after COVID-19 infection.

“I think it is possible that there could be many more cases,” said lead author Domenico Restivo, MD, of the Garibaldi Hospital, Catania, Italy. “In fact, myasthenia gravis could be underestimated especially in the course of COVID-19 infection in which a specific muscular weakness is frequently present. For this reason, this association is easy to miss if not top of mind,” Dr. Restivo said.

None of the three patients had previous neurologic or autoimmune disorders. In all three cases, symptoms of myasthenia gravis appeared within 5-7 days after onset of fever caused by SARS-CoV-2 infection. The time from presumed SARS-CoV-2 infection to myasthenia gravis symptoms “is consistent with the time from infection to symptoms in other neurologic disorders triggered by infections,” the investigators reported.

The findings were published online August 10 in Annals of Internal Medicine.
 

First patients

The first patient described in the report was a 64-year-old man who had a fever as high as 39° C (102.2° F) for 4 days. Five days after fever onset, he developed diplopia and muscle fatigue. The patient’s neurologic examination was “unremarkable.” Computed tomography (CT) of the thorax excluded thymoma, and findings on chest radiograph were normal. He tested positive for SARS-CoV-2 on nasopharyngeal swab and real-time reverse transcriptase polymerase chain reaction (RT-PCR).

The patient’s symptoms led the investigators to suspect myasthenia gravis. Repetitive stimulation of the patient’s facial nerve showed a 57% decrement, confirming involvement of the postsynaptic neuromuscular junction. The concentration of AChR antibodies in serum was also elevated (22.8 pmol/L; reference range, <0.4 pmol/L). The patient was treated with pyridostigmine bromide and prednisone and had a response “typical for someone with myasthenia gravis,” the researchers wrote.

The second patient was a 68-year-old man who had a fever as high as 38.8° C (101.8° F) for 7 days. On day 7, he developed muscle fatigue, diplopia, and dysphagia. Findings of a chest CT and neurologic exam were normal. Nasopharyngeal swab and RT-PCR testing for COVID-19 were positive. As with the first patient, myasthenia gravis was suspected because of the patient’s symptoms. Repetitive nerve stimulation revealed a postsynaptic deficit of neuromuscular transmission of the facial (52%) and ulnar (21%) nerves. His serum AChR antibody level was elevated (27.6 pmol/L). The patient improved after one cycle of intravenous immunoglobulin treatment.
 

Possible mechanisms

The third patient was a 71-year-old woman with cough and a fever up to 38.6° C (101.5° F) for 6 days. She initially tested negative for SARS-CoV-2 on nasopharyngeal swab and RT-PCR. Five days after her symptoms began, she developed bilateral ocular ptosis, diplopia, and hypophonia. CT of the thorax excluded thymoma but showed bilateral interstitial pneumonia. On day 6, she developed dysphagia and respiratory failure, and was transferred to the ICU where she received mechanical ventilation.

Repetitive nerve stimulation revealed a postsynaptic deficit of neuromuscular transmission of the ulnar nerve (56%), and her serum AChR antibody level was elevated (35.6 pmol/L). Five days later, a second nasopharyngeal swab test for SARS-CoV-2 was positive. The patient improved following plasmapheresis treatment and was successfully extubated.

The investigators noted that this patient received hydroxychloroquine the day after the onset of neurologic symptoms, but the drug was withdrawn a day later, so they do not believe that it caused the symptoms of myasthenia gravis.

The observations in these three patients are “consistent with reports of other infections that induce autoimmune disorders, as well as with the growing evidence of other neurologic disorders with presumed autoimmune mechanisms after COVID-19 onset,” the researchers wrote.

They offered several possible explanations for the link between COVID-19 and myasthenia gravis. “Antibodies that are directed against SARS-CoV-2 proteins may cross-react with AChR subunits, because the virus has epitopes that are similar to components of the neuromuscular junction; this is known to occur in other neurologic autoimmune disorders after infection. Alternatively, COVID-19 infection may break immunologic self-tolerance,” the investigators wrote.

“The main message for clinicians is that myasthenia gravis, as well as other neurological disorders associated with autoimmunity, could occur in the course of SARS-CoV-2 infection,” Dr. Restivo said. Prompt recognition of the disease “could lead to a drug treatment that limits its evolution as quickly as possible,” he added.
 

An “unmasking”

Commenting on the findings, Anthony Geraci, MD, director of neuromuscular medicine, Northwell Health, Great Neck, N.Y., said these case reports of myasthenia gravis after SARS-CoV-2 infection are “not unique or novel as there has been a long understanding that seropositive [AChR antibody-positive] myasthenia gravis can and is frequently ‘unmasked’ in the setting” of several viral and bacterial infections.

“Antibodies in myasthenia gravis are of a type that take several weeks to develop to measurable levels as in the reported cases by Restivo et al., giving strong support to the notion that subclinical myasthenia gravis can be immunologically upregulated in the setting of viral infection and this is a far more likely explanation of the observed association reported,” added Dr. Geraci, who was not involved with the research.

He noted that, at his institution, “we have also observed ocular myasthenia gravis emerge in patients with SARS-CoV-2 infection, with similar double vision and lid droop, as we have seen similarly in patients with Zika, West Nile, and other viral infections, as well as a multiplicity of bacterial infections.”

“Most of our observed patients have responded to treatment much the same as reported by the three cases from Restivo and colleagues,” Dr.Geraci reported.

The authors of the study disclosed no conflicts of interest.

A version of this article originally appeared on Medscape.com.

A poor combined score on tests of hearing, vision, smell, and touch is associated with a higher risk for dementia and cognitive decline among older adults, new research suggests. The study, which included almost 1,800 participants, adds to emerging evidence that even mild levels of multisensory impairment are associated with accelerated cognitive aging, the researchers noted.

Clinicians should be aware of this link between sensory impairment and dementia risk, said lead author Willa Brenowitz, PhD, assistant professor, department of psychiatry and behavioral sciences, University of California, San Francisco. “Many of these impairments are treatable, or at least physicians can monitor them; and this can improve quality of life, even if it doesn’t improve dementia risk.”

The findings were published online July 12 in Alzheimer’s and Dementia.
 

Additive effects

Previous research has focused on the link between dementia and individual senses, but this new work is unique in that it focuses on the additive effects of multiple impairments in sensory function, said Dr. Brenowitz. The study included 1,794 dementia-free participants in their 70s from the Health, Aging and Body Composition study, a prospective cohort study of healthy Black and White men and women.

Researchers tested participants’ hearing using a pure tone average without hearing aids and vision using contrast sensitivity with glasses permitted. They also measured vibrations in the big toe to assess touch and had participants identify distinctive odors such as paint thinner, roses, lemons, and onions to assess smell.

A score of 0-3 was assigned based on sample quartiles for each of the four sensory functions. Individuals with the best quartile were assigned a score of 0 and those with the worst were assigned a score of 3.

The investigators added scores across all senses to create a summary score of multisensory function (0-12) and classified the participants into tertiles of good, medium, and poor. Individuals with a score of 0 would have good function in all senses, whereas those with 12 would have poor function in all senses. Those with medium scores could have a mix of impairments.

Participants with good multisensory function were more likely to be healthier than those with poor function. They were also significantly more likely to have completed high school (85.0% vs. 72.1%), were significantly less likely to have diabetes (16.9% vs. 27.9%), and were marginally less likely to have cardiovascular disease, high blood pressure, and history of stroke.

Investigators measured cognition using the Modified Mini-Mental State (3MS) examination, a test of global cognitive function, and the Digit Symbol Substitution Test (DSST), a measure of cognitive processing speed. Cognitive testing was carried out at the beginning of the study and repeated every other year.

Dementia was defined as the use of dementia medication, being hospitalized with dementia as a primary or secondary diagnosis, or having a 3MS score 1.5 standard deviations lower than the race-stratified Health ABC study baseline mean.

Over an average follow-up of 6.3 years, 18% of participants developed dementia.
 

Dose-response increase

Results showed that, with worsening multisensory function score, the risk for dementia increased in a dose-response manner. In models adjusted for demographics and health conditions, participants with a poor multisensory function score were more than twice as likely to develop dementia than those with a good score (hazard ratio, 2.05; 95% confidence interval, 1.50-2.81; P < .001). Those with a middle multisensory function score were 1.45 times more likely to develop dementia (HR, 1.45; 95% CI, 1.09-1.91; P < .001).

Even a 1-point worse multisensory function score was associated with a 14% higher risk for dementia (95% CI, 8%-21%), while a 4-point worse score was associated with 71% higher risk for dementia (95% CI, 38%-211%).

Smell was the sensory function most strongly associated with dementia risk. Participants whose sense of smell declined by 10% had a 19% higher risk for dementia versus a 1%-3% higher risk for declines in vision, hearing, and touch.

It is not clear why smell was a stronger determinant of dementia risk. However, loss of this sense is often considered to be a marker for Alzheimer’s disease “because it is closely linked with brain regions that are affected” in that disease, said Dr. Brenowitz.

However, that does not necessarily mean smell is more important than vision or hearing, she added. “Even if hearing and vision have a smaller contribution to dementia, they have a stronger potential for intervention.” The findings suggest “some additive or cumulative” effects for loss of the different senses. “There’s an association above and beyond those which can be attributed to individual sensory domains,” she said.
 

Frailty link

After including mobility, which is a potential mediator, estimates for the multisensory function score were slightly lower. “Walking speed is pretty strongly associated with dementia risk,” Dr. Brenowitz noted. Physical frailty might help explain the link between sensory impairment and dementia risk. “It’s not clear if that’s because people with dementia are declining or because people with frailty are especially vulnerable to dementia,” she said.

The researchers also assessed the role of social support, another potential mechanism by which sensory decline, especially in hearing and vision, could influence dementia risk. Although the study did not find substantial differences in social support measures, the investigators noted that questions assessing social support were limited in scope.

Interactions between multisensory function score and race, APOE e4 allele status, and sex were not significant.

Worsening multisensory function was also linked to faster annual rates of cognitive decline as measured by both the 3MS and DSST. Each 1-point worse score was associated with faster decline (P < .05), even after adjustment for demographics and health conditions.
 

Possible mechanisms

A number of possible mechanisms may explain the link between poor sensory function and dementia. It could be that neurodegeneration underlying dementia affects the senses, or vision and/or hearing loss leads to social isolation and poor mental health, which in turn could affect dementia risk, the researchers wrote. It also is possible that cardiovascular disease or diabetes affect both dementia risk and sensory impairment.

Dr. Brenowitz noted that, because cognitive tests rely on a certain degree of vision and hearing, impairment of these senses may complicate such tests. Still to be determined is whether correcting sensory impairments, such as wearing corrective lenses or hearing aids, affects dementia risk.

Meanwhile, it might be a good idea to more regularly check sensory function, especially vision and hearing, the researchers suggested. These functions affect various aspects of health and can be assessed rather easily. However, because smell is so strongly associated with dementia risk, Dr. Brenowitz said she would like to see it also become “part of a screening tool.”

A possible study limitation cited was that the researchers checked sensory function only once. “Most likely, some of these would change over time, but at least it captured sensory function at one point,” Dr. Brenowitz said.
 

“Sheds further light”

Commenting on the study, Jo V. Rushworth, PhD, associate professor and national teaching fellow, De Montfort University Leicester (England), said it “sheds further light on the emerging links” between multisensory impairment and cognitive decline leading to dementia. “The authors show that people with even mild loss of function in various senses are more likely to develop cognitive impairment.”

Dr. Rushworth was not involved with the study but has done research in the area.

The current results suggest that measuring patients’ hearing, vision, sense of smell, and touch might “flag at-risk groups” who could be targeted for dementia prevention strategies, Dr. Rushworth noted. Such tests are noninvasive and potentially less distressing than other methods of diagnosing dementia. “Importantly, the relatively low cost and simplicity of sensory tests offer the potential for more frequent testing and the use of these methods in areas of the world where medical facilities and resources are limited.”

This new study raises the question of whether the observed sensory impairments are a cause or an effect of dementia, Dr. Rushworth noted. “As the authors suggest, decreased sensory function can lead to a decrease in social engagement, mobility, and other factors which would usually contribute to counteracting cognitive decline.”

The study raises other questions, too, said Dr. Rushworth. She noted that the participants who experienced more severe sensory impairments were, on average, 2 years older than those with the least impairments. “To what degree were the observed sensory deficits linked to normal aging rather than dementia?”

As well, Dr. Rushworth pointed out that the molecular mechanisms that “kick-start” dementia are believed to occur in midlife – so possibly at an age younger than the study participants. “Do younger people of a ‘predementia’ age range display multisensory impairments?”

Because study participants could wear glasses during vision tests but were not allowed to wear hearing aids for the hearing tests, further standardization of sensory impairment is required, Dr. Rushworth said.

“Future studies will be essential in determining the value of clinical measurement of multisensory impairment as a possible dementia indicator and prevention strategy,” she concluded.

The study was funded by the National Institute on Aging, the National Institute of Nursing Research, and the Alzheimer’s Association. Dr. Brenowitz and Dr. Rushworth have reported no relevant financial relationships.

A version of this article originally appeared on Medscape.com.

A poor combined score on tests of hearing, vision, smell, and touch is associated with a higher risk for dementia and cognitive decline among older adults, new research suggests. The study, which included almost 1,800 participants, adds to emerging evidence that even mild levels of multisensory impairment are associated with accelerated cognitive aging, the researchers noted.

Clinicians should be aware of this link between sensory impairment and dementia risk, said lead author Willa Brenowitz, PhD, assistant professor, department of psychiatry and behavioral sciences, University of California, San Francisco. “Many of these impairments are treatable, or at least physicians can monitor them; and this can improve quality of life, even if it doesn’t improve dementia risk.”

The findings were published online July 12 in Alzheimer’s and Dementia.
 

Additive effects

Previous research has focused on the link between dementia and individual senses, but this new work is unique in that it focuses on the additive effects of multiple impairments in sensory function, said Dr. Brenowitz. The study included 1,794 dementia-free participants in their 70s from the Health, Aging and Body Composition study, a prospective cohort study of healthy Black and White men and women.

Researchers tested participants’ hearing using a pure tone average without hearing aids and vision using contrast sensitivity with glasses permitted. They also measured vibrations in the big toe to assess touch and had participants identify distinctive odors such as paint thinner, roses, lemons, and onions to assess smell.

A score of 0-3 was assigned based on sample quartiles for each of the four sensory functions. Individuals with the best quartile were assigned a score of 0 and those with the worst were assigned a score of 3.

The investigators added scores across all senses to create a summary score of multisensory function (0-12) and classified the participants into tertiles of good, medium, and poor. Individuals with a score of 0 would have good function in all senses, whereas those with 12 would have poor function in all senses. Those with medium scores could have a mix of impairments.

Participants with good multisensory function were more likely to be healthier than those with poor function. They were also significantly more likely to have completed high school (85.0% vs. 72.1%), were significantly less likely to have diabetes (16.9% vs. 27.9%), and were marginally less likely to have cardiovascular disease, high blood pressure, and history of stroke.

Investigators measured cognition using the Modified Mini-Mental State (3MS) examination, a test of global cognitive function, and the Digit Symbol Substitution Test (DSST), a measure of cognitive processing speed. Cognitive testing was carried out at the beginning of the study and repeated every other year.

Dementia was defined as the use of dementia medication, being hospitalized with dementia as a primary or secondary diagnosis, or having a 3MS score 1.5 standard deviations lower than the race-stratified Health ABC study baseline mean.

Over an average follow-up of 6.3 years, 18% of participants developed dementia.
 

Dose-response increase

Results showed that, with worsening multisensory function score, the risk for dementia increased in a dose-response manner. In models adjusted for demographics and health conditions, participants with a poor multisensory function score were more than twice as likely to develop dementia than those with a good score (hazard ratio, 2.05; 95% confidence interval, 1.50-2.81; P < .001). Those with a middle multisensory function score were 1.45 times more likely to develop dementia (HR, 1.45; 95% CI, 1.09-1.91; P < .001).

Even a 1-point worse multisensory function score was associated with a 14% higher risk for dementia (95% CI, 8%-21%), while a 4-point worse score was associated with 71% higher risk for dementia (95% CI, 38%-211%).

Smell was the sensory function most strongly associated with dementia risk. Participants whose sense of smell declined by 10% had a 19% higher risk for dementia versus a 1%-3% higher risk for declines in vision, hearing, and touch.

It is not clear why smell was a stronger determinant of dementia risk. However, loss of this sense is often considered to be a marker for Alzheimer’s disease “because it is closely linked with brain regions that are affected” in that disease, said Dr. Brenowitz.

However, that does not necessarily mean smell is more important than vision or hearing, she added. “Even if hearing and vision have a smaller contribution to dementia, they have a stronger potential for intervention.” The findings suggest “some additive or cumulative” effects for loss of the different senses. “There’s an association above and beyond those which can be attributed to individual sensory domains,” she said.
 

Frailty link

After including mobility, which is a potential mediator, estimates for the multisensory function score were slightly lower. “Walking speed is pretty strongly associated with dementia risk,” Dr. Brenowitz noted. Physical frailty might help explain the link between sensory impairment and dementia risk. “It’s not clear if that’s because people with dementia are declining or because people with frailty are especially vulnerable to dementia,” she said.

The researchers also assessed the role of social support, another potential mechanism by which sensory decline, especially in hearing and vision, could influence dementia risk. Although the study did not find substantial differences in social support measures, the investigators noted that questions assessing social support were limited in scope.

Interactions between multisensory function score and race, APOE e4 allele status, and sex were not significant.

Worsening multisensory function was also linked to faster annual rates of cognitive decline as measured by both the 3MS and DSST. Each 1-point worse score was associated with faster decline (P < .05), even after adjustment for demographics and health conditions.
 

Possible mechanisms

A number of possible mechanisms may explain the link between poor sensory function and dementia. It could be that neurodegeneration underlying dementia affects the senses, or vision and/or hearing loss leads to social isolation and poor mental health, which in turn could affect dementia risk, the researchers wrote. It also is possible that cardiovascular disease or diabetes affect both dementia risk and sensory impairment.

Dr. Brenowitz noted that, because cognitive tests rely on a certain degree of vision and hearing, impairment of these senses may complicate such tests. Still to be determined is whether correcting sensory impairments, such as wearing corrective lenses or hearing aids, affects dementia risk.

Meanwhile, it might be a good idea to more regularly check sensory function, especially vision and hearing, the researchers suggested. These functions affect various aspects of health and can be assessed rather easily. However, because smell is so strongly associated with dementia risk, Dr. Brenowitz said she would like to see it also become “part of a screening tool.”

A possible study limitation cited was that the researchers checked sensory function only once. “Most likely, some of these would change over time, but at least it captured sensory function at one point,” Dr. Brenowitz said.
 

“Sheds further light”

Commenting on the study, Jo V. Rushworth, PhD, associate professor and national teaching fellow, De Montfort University Leicester (England), said it “sheds further light on the emerging links” between multisensory impairment and cognitive decline leading to dementia. “The authors show that people with even mild loss of function in various senses are more likely to develop cognitive impairment.”

Dr. Rushworth was not involved with the study but has done research in the area.

The current results suggest that measuring patients’ hearing, vision, sense of smell, and touch might “flag at-risk groups” who could be targeted for dementia prevention strategies, Dr. Rushworth noted. Such tests are noninvasive and potentially less distressing than other methods of diagnosing dementia. “Importantly, the relatively low cost and simplicity of sensory tests offer the potential for more frequent testing and the use of these methods in areas of the world where medical facilities and resources are limited.”

This new study raises the question of whether the observed sensory impairments are a cause or an effect of dementia, Dr. Rushworth noted. “As the authors suggest, decreased sensory function can lead to a decrease in social engagement, mobility, and other factors which would usually contribute to counteracting cognitive decline.”

The study raises other questions, too, said Dr. Rushworth. She noted that the participants who experienced more severe sensory impairments were, on average, 2 years older than those with the least impairments. “To what degree were the observed sensory deficits linked to normal aging rather than dementia?”

As well, Dr. Rushworth pointed out that the molecular mechanisms that “kick-start” dementia are believed to occur in midlife – so possibly at an age younger than the study participants. “Do younger people of a ‘predementia’ age range display multisensory impairments?”

Because study participants could wear glasses during vision tests but were not allowed to wear hearing aids for the hearing tests, further standardization of sensory impairment is required, Dr. Rushworth said.

“Future studies will be essential in determining the value of clinical measurement of multisensory impairment as a possible dementia indicator and prevention strategy,” she concluded.

The study was funded by the National Institute on Aging, the National Institute of Nursing Research, and the Alzheimer’s Association. Dr. Brenowitz and Dr. Rushworth have reported no relevant financial relationships.

A version of this article originally appeared on Medscape.com.

A poor combined score on tests of hearing, vision, smell, and touch is associated with a higher risk for dementia and cognitive decline among older adults, new research suggests. The study, which included almost 1,800 participants, adds to emerging evidence that even mild levels of multisensory impairment are associated with accelerated cognitive aging, the researchers noted.

Clinicians should be aware of this link between sensory impairment and dementia risk, said lead author Willa Brenowitz, PhD, assistant professor, department of psychiatry and behavioral sciences, University of California, San Francisco. “Many of these impairments are treatable, or at least physicians can monitor them; and this can improve quality of life, even if it doesn’t improve dementia risk.”

The findings were published online July 12 in Alzheimer’s and Dementia.
 

Additive effects

Previous research has focused on the link between dementia and individual senses, but this new work is unique in that it focuses on the additive effects of multiple impairments in sensory function, said Dr. Brenowitz. The study included 1,794 dementia-free participants in their 70s from the Health, Aging and Body Composition study, a prospective cohort study of healthy Black and White men and women.

Researchers tested participants’ hearing using a pure tone average without hearing aids and vision using contrast sensitivity with glasses permitted. They also measured vibrations in the big toe to assess touch and had participants identify distinctive odors such as paint thinner, roses, lemons, and onions to assess smell.

A score of 0-3 was assigned based on sample quartiles for each of the four sensory functions. Individuals with the best quartile were assigned a score of 0 and those with the worst were assigned a score of 3.

The investigators added scores across all senses to create a summary score of multisensory function (0-12) and classified the participants into tertiles of good, medium, and poor. Individuals with a score of 0 would have good function in all senses, whereas those with 12 would have poor function in all senses. Those with medium scores could have a mix of impairments.

Participants with good multisensory function were more likely to be healthier than those with poor function. They were also significantly more likely to have completed high school (85.0% vs. 72.1%), were significantly less likely to have diabetes (16.9% vs. 27.9%), and were marginally less likely to have cardiovascular disease, high blood pressure, and history of stroke.

Investigators measured cognition using the Modified Mini-Mental State (3MS) examination, a test of global cognitive function, and the Digit Symbol Substitution Test (DSST), a measure of cognitive processing speed. Cognitive testing was carried out at the beginning of the study and repeated every other year.

Dementia was defined as the use of dementia medication, being hospitalized with dementia as a primary or secondary diagnosis, or having a 3MS score 1.5 standard deviations lower than the race-stratified Health ABC study baseline mean.

Over an average follow-up of 6.3 years, 18% of participants developed dementia.
 

Dose-response increase

Results showed that, with worsening multisensory function score, the risk for dementia increased in a dose-response manner. In models adjusted for demographics and health conditions, participants with a poor multisensory function score were more than twice as likely to develop dementia than those with a good score (hazard ratio, 2.05; 95% confidence interval, 1.50-2.81; P < .001). Those with a middle multisensory function score were 1.45 times more likely to develop dementia (HR, 1.45; 95% CI, 1.09-1.91; P < .001).

Even a 1-point worse multisensory function score was associated with a 14% higher risk for dementia (95% CI, 8%-21%), while a 4-point worse score was associated with 71% higher risk for dementia (95% CI, 38%-211%).

Smell was the sensory function most strongly associated with dementia risk. Participants whose sense of smell declined by 10% had a 19% higher risk for dementia versus a 1%-3% higher risk for declines in vision, hearing, and touch.

It is not clear why smell was a stronger determinant of dementia risk. However, loss of this sense is often considered to be a marker for Alzheimer’s disease “because it is closely linked with brain regions that are affected” in that disease, said Dr. Brenowitz.

However, that does not necessarily mean smell is more important than vision or hearing, she added. “Even if hearing and vision have a smaller contribution to dementia, they have a stronger potential for intervention.” The findings suggest “some additive or cumulative” effects for loss of the different senses. “There’s an association above and beyond those which can be attributed to individual sensory domains,” she said.
 

Frailty link

After including mobility, which is a potential mediator, estimates for the multisensory function score were slightly lower. “Walking speed is pretty strongly associated with dementia risk,” Dr. Brenowitz noted. Physical frailty might help explain the link between sensory impairment and dementia risk. “It’s not clear if that’s because people with dementia are declining or because people with frailty are especially vulnerable to dementia,” she said.

The researchers also assessed the role of social support, another potential mechanism by which sensory decline, especially in hearing and vision, could influence dementia risk. Although the study did not find substantial differences in social support measures, the investigators noted that questions assessing social support were limited in scope.

Interactions between multisensory function score and race, APOE e4 allele status, and sex were not significant.

Worsening multisensory function was also linked to faster annual rates of cognitive decline as measured by both the 3MS and DSST. Each 1-point worse score was associated with faster decline (P < .05), even after adjustment for demographics and health conditions.
 

Possible mechanisms

A number of possible mechanisms may explain the link between poor sensory function and dementia. It could be that neurodegeneration underlying dementia affects the senses, or vision and/or hearing loss leads to social isolation and poor mental health, which in turn could affect dementia risk, the researchers wrote. It also is possible that cardiovascular disease or diabetes affect both dementia risk and sensory impairment.

Dr. Brenowitz noted that, because cognitive tests rely on a certain degree of vision and hearing, impairment of these senses may complicate such tests. Still to be determined is whether correcting sensory impairments, such as wearing corrective lenses or hearing aids, affects dementia risk.

Meanwhile, it might be a good idea to more regularly check sensory function, especially vision and hearing, the researchers suggested. These functions affect various aspects of health and can be assessed rather easily. However, because smell is so strongly associated with dementia risk, Dr. Brenowitz said she would like to see it also become “part of a screening tool.”

A possible study limitation cited was that the researchers checked sensory function only once. “Most likely, some of these would change over time, but at least it captured sensory function at one point,” Dr. Brenowitz said.
 

“Sheds further light”

Commenting on the study, Jo V. Rushworth, PhD, associate professor and national teaching fellow, De Montfort University Leicester (England), said it “sheds further light on the emerging links” between multisensory impairment and cognitive decline leading to dementia. “The authors show that people with even mild loss of function in various senses are more likely to develop cognitive impairment.”

Dr. Rushworth was not involved with the study but has done research in the area.

The current results suggest that measuring patients’ hearing, vision, sense of smell, and touch might “flag at-risk groups” who could be targeted for dementia prevention strategies, Dr. Rushworth noted. Such tests are noninvasive and potentially less distressing than other methods of diagnosing dementia. “Importantly, the relatively low cost and simplicity of sensory tests offer the potential for more frequent testing and the use of these methods in areas of the world where medical facilities and resources are limited.”

This new study raises the question of whether the observed sensory impairments are a cause or an effect of dementia, Dr. Rushworth noted. “As the authors suggest, decreased sensory function can lead to a decrease in social engagement, mobility, and other factors which would usually contribute to counteracting cognitive decline.”

The study raises other questions, too, said Dr. Rushworth. She noted that the participants who experienced more severe sensory impairments were, on average, 2 years older than those with the least impairments. “To what degree were the observed sensory deficits linked to normal aging rather than dementia?”

As well, Dr. Rushworth pointed out that the molecular mechanisms that “kick-start” dementia are believed to occur in midlife – so possibly at an age younger than the study participants. “Do younger people of a ‘predementia’ age range display multisensory impairments?”

Because study participants could wear glasses during vision tests but were not allowed to wear hearing aids for the hearing tests, further standardization of sensory impairment is required, Dr. Rushworth said.

“Future studies will be essential in determining the value of clinical measurement of multisensory impairment as a possible dementia indicator and prevention strategy,” she concluded.

The study was funded by the National Institute on Aging, the National Institute of Nursing Research, and the Alzheimer’s Association. Dr. Brenowitz and Dr. Rushworth have reported no relevant financial relationships.

A version of this article originally appeared on Medscape.com.

Compared with their counterparts who get more relief, patients with difficult-to-treat migraine are more likely to delay acute treatment and take over-the-counter and opioid painkillers. They are also more likely to have depression and impairment. Overall, insufficient responders—patients less likely to get relief shortly after acute treatment—are “more medically and psychosocially complex,” wrote the authors of the study, which appeared in the July/August issue of Headache.

Common characteristics of insufficient responders

The researchers, led by Louise Lombard, M Nutr, of Eli Lilly and Company, analyzed data from a 2014 cross-sectional survey. They tracked 583 patients with migraine, including 200 (34%) who were considered insufficient responders because they failed to achieve freedom from pain within 2 hours of acute treatment in at least four of five attacks.

The insufficient and sufficient responder groups were similar in age (mean = 40 for both) and gender (80% and 75% female, respectively, P = .170) and race (72% and 77% white, P = .279).

However, insufficient responders were clearly more affected by headaches, multiple treatments, and other burdens. Compared with those who had better responses to treatment, they were more likely to have four or more migraine headache days per month (46% vs. 31%), rebound or medication-overuse headaches (16% vs. 7%) and chronic migraine (12% vs. 5%, all P < .05).

They were also more likely have comorbid depression (38% vs. 22%) and psychological conditions other than depression and anxiety (8% vs. 4%, all P < .05).

As for treatment, insufficient response was higher in patients who waited until the appearance of pain to take medication (odds ratio = 1.83, 95% confidence interval [CI] 1.15–2.92, P = .011, after adjustment for covariates). And insufficient responders were more likely to have been prescribed at least three unique preventive regimens (12% vs. 6%), to take over-the-counter medications (50% vs. 38%) and to take opioid painkillers (16% vs. 8%, all P < .05).

The authors, who caution that the study does not prove cause and effect, wrote that insufficient responders “may benefit from education on how and when to use current treatments.”
 

Managing insufficient responders

Neurology Reviews editor-in-chief Alan M. Rapoport, MD, said the study “confirms a lot of what we knew.” Dr, Rapoport, who was not involved in the study, is clinical professor of neurology at the University of California, Los Angeles.

“As expected, the insufficient responders used more opioids and over-the-counter medications, which is not the ideal way to treat migraine,” he said. “That probably caused them to have medication-overuse headache, which might have caused them to respond poorly to even the best treatment regimen. They also had more severe symptoms, more comorbidities, and a poorer quality of life. They also had more impairment and greater impact on work, with more of them unemployed.”

The insufficient responders also “took medication at the time or after the pain began, rather than before it when they thought the attack was beginning due to premonitory symptoms,” he said.

Dr. Rapoport also noted a surprising and unusual finding: Patients who did not report sensitivity to light as their most bothersome symptom were more likely to be insufficient responders (OR = 2.3, 95% CI [1.21–4.37], P = .011). “In all recent migraine studies,” he said, “the majority of patients selected photophobia as their most bothersome symptom.”

In the big picture, he said, the study suggests that “a third triptan does not seem to work better than the first two, patients with medication-overuse headache and chronic migraine and those not on preventive medication do not respond that well to acute care treatment, and the same is true when depression is present.”

No study funding was reported. Four study authors reported ties with Eli Lilly, and two reported employment by Adelphi Real World, which provided the survey results..

SOURCE: Lombard L et al. Headache. 2020;60(7):1325-39. doi: 10.1111/head.13835.

Compared with their counterparts who get more relief, patients with difficult-to-treat migraine are more likely to delay acute treatment and take over-the-counter and opioid painkillers. They are also more likely to have depression and impairment. Overall, insufficient responders—patients less likely to get relief shortly after acute treatment—are “more medically and psychosocially complex,” wrote the authors of the study, which appeared in the July/August issue of Headache.

Common characteristics of insufficient responders

The researchers, led by Louise Lombard, M Nutr, of Eli Lilly and Company, analyzed data from a 2014 cross-sectional survey. They tracked 583 patients with migraine, including 200 (34%) who were considered insufficient responders because they failed to achieve freedom from pain within 2 hours of acute treatment in at least four of five attacks.

The insufficient and sufficient responder groups were similar in age (mean = 40 for both) and gender (80% and 75% female, respectively, P = .170) and race (72% and 77% white, P = .279).

However, insufficient responders were clearly more affected by headaches, multiple treatments, and other burdens. Compared with those who had better responses to treatment, they were more likely to have four or more migraine headache days per month (46% vs. 31%), rebound or medication-overuse headaches (16% vs. 7%) and chronic migraine (12% vs. 5%, all P < .05).

They were also more likely have comorbid depression (38% vs. 22%) and psychological conditions other than depression and anxiety (8% vs. 4%, all P < .05).

As for treatment, insufficient response was higher in patients who waited until the appearance of pain to take medication (odds ratio = 1.83, 95% confidence interval [CI] 1.15–2.92, P = .011, after adjustment for covariates). And insufficient responders were more likely to have been prescribed at least three unique preventive regimens (12% vs. 6%), to take over-the-counter medications (50% vs. 38%) and to take opioid painkillers (16% vs. 8%, all P < .05).

The authors, who caution that the study does not prove cause and effect, wrote that insufficient responders “may benefit from education on how and when to use current treatments.”
 

Managing insufficient responders

Neurology Reviews editor-in-chief Alan M. Rapoport, MD, said the study “confirms a lot of what we knew.” Dr, Rapoport, who was not involved in the study, is clinical professor of neurology at the University of California, Los Angeles.

“As expected, the insufficient responders used more opioids and over-the-counter medications, which is not the ideal way to treat migraine,” he said. “That probably caused them to have medication-overuse headache, which might have caused them to respond poorly to even the best treatment regimen. They also had more severe symptoms, more comorbidities, and a poorer quality of life. They also had more impairment and greater impact on work, with more of them unemployed.”

The insufficient responders also “took medication at the time or after the pain began, rather than before it when they thought the attack was beginning due to premonitory symptoms,” he said.

Dr. Rapoport also noted a surprising and unusual finding: Patients who did not report sensitivity to light as their most bothersome symptom were more likely to be insufficient responders (OR = 2.3, 95% CI [1.21–4.37], P = .011). “In all recent migraine studies,” he said, “the majority of patients selected photophobia as their most bothersome symptom.”

In the big picture, he said, the study suggests that “a third triptan does not seem to work better than the first two, patients with medication-overuse headache and chronic migraine and those not on preventive medication do not respond that well to acute care treatment, and the same is true when depression is present.”

No study funding was reported. Four study authors reported ties with Eli Lilly, and two reported employment by Adelphi Real World, which provided the survey results..

SOURCE: Lombard L et al. Headache. 2020;60(7):1325-39. doi: 10.1111/head.13835.

Compared with their counterparts who get more relief, patients with difficult-to-treat migraine are more likely to delay acute treatment and take over-the-counter and opioid painkillers. They are also more likely to have depression and impairment. Overall, insufficient responders—patients less likely to get relief shortly after acute treatment—are “more medically and psychosocially complex,” wrote the authors of the study, which appeared in the July/August issue of Headache.

Common characteristics of insufficient responders

The researchers, led by Louise Lombard, M Nutr, of Eli Lilly and Company, analyzed data from a 2014 cross-sectional survey. They tracked 583 patients with migraine, including 200 (34%) who were considered insufficient responders because they failed to achieve freedom from pain within 2 hours of acute treatment in at least four of five attacks.

The insufficient and sufficient responder groups were similar in age (mean = 40 for both) and gender (80% and 75% female, respectively, P = .170) and race (72% and 77% white, P = .279).

However, insufficient responders were clearly more affected by headaches, multiple treatments, and other burdens. Compared with those who had better responses to treatment, they were more likely to have four or more migraine headache days per month (46% vs. 31%), rebound or medication-overuse headaches (16% vs. 7%) and chronic migraine (12% vs. 5%, all P < .05).

They were also more likely have comorbid depression (38% vs. 22%) and psychological conditions other than depression and anxiety (8% vs. 4%, all P < .05).

As for treatment, insufficient response was higher in patients who waited until the appearance of pain to take medication (odds ratio = 1.83, 95% confidence interval [CI] 1.15–2.92, P = .011, after adjustment for covariates). And insufficient responders were more likely to have been prescribed at least three unique preventive regimens (12% vs. 6%), to take over-the-counter medications (50% vs. 38%) and to take opioid painkillers (16% vs. 8%, all P < .05).

The authors, who caution that the study does not prove cause and effect, wrote that insufficient responders “may benefit from education on how and when to use current treatments.”
 

Managing insufficient responders

Neurology Reviews editor-in-chief Alan M. Rapoport, MD, said the study “confirms a lot of what we knew.” Dr, Rapoport, who was not involved in the study, is clinical professor of neurology at the University of California, Los Angeles.

“As expected, the insufficient responders used more opioids and over-the-counter medications, which is not the ideal way to treat migraine,” he said. “That probably caused them to have medication-overuse headache, which might have caused them to respond poorly to even the best treatment regimen. They also had more severe symptoms, more comorbidities, and a poorer quality of life. They also had more impairment and greater impact on work, with more of them unemployed.”

The insufficient responders also “took medication at the time or after the pain began, rather than before it when they thought the attack was beginning due to premonitory symptoms,” he said.

Dr. Rapoport also noted a surprising and unusual finding: Patients who did not report sensitivity to light as their most bothersome symptom were more likely to be insufficient responders (OR = 2.3, 95% CI [1.21–4.37], P = .011). “In all recent migraine studies,” he said, “the majority of patients selected photophobia as their most bothersome symptom.”

In the big picture, he said, the study suggests that “a third triptan does not seem to work better than the first two, patients with medication-overuse headache and chronic migraine and those not on preventive medication do not respond that well to acute care treatment, and the same is true when depression is present.”

No study funding was reported. Four study authors reported ties with Eli Lilly, and two reported employment by Adelphi Real World, which provided the survey results..

SOURCE: Lombard L et al. Headache. 2020;60(7):1325-39. doi: 10.1111/head.13835.

Concussion is associated with increased risk for subsequent development of attention-deficit/hyperactivity disorder (ADHD), as well as dementia and Parkinson’s disease, new research suggests. Results from a retrospective, population-based cohort study showed that controlling for socioeconomic status and overall health did not significantly affect this association.

The link between concussion and risk for ADHD and for mood and anxiety disorder was stronger in the women than in the men. In addition, having a history of multiple concussions strengthened the association between concussion and subsequent mood and anxiety disorder, dementia, and Parkinson’s disease compared with experiencing just one concussion.

The findings are similar to those of previous studies, noted lead author Marc P. Morissette, PhD, research assistant at the Pan Am Clinic Foundation in Winnipeg, Manitoba, Canada. “The main methodological differences separating our study from previous studies in this area is a focus on concussion-specific injuries identified from medical records and the potential for study participants to have up to 25 years of follow-up data,” said Dr. Morissette.

The findings were published online July 27 in Family Medicine and Community Health, a BMJ journal.
 

Almost 190,000 participants

Several studies have shown associations between head injury and increased risk for ADHD, depression, anxiety, Alzheimer’s disease, and Parkinson’s disease. However, many of these studies relied on self-reported medical history, included all forms of traumatic brain injury, and failed to adjust for preexisting health conditions.

An improved understanding of concussion and the risks associated with it could help physicians manage their patients’ long-term needs, the investigators noted.

In the current study, the researchers examined anonymized administrative health data collected between the periods of 1990–1991 and 2014–2015 in the Manitoba Population Research Data Repository at the Manitoba Center for Health Policy.

Eligible patients had been diagnosed with concussion in accordance with standard criteria. Participants were excluded if they had been diagnosed with dementia or Parkinson’s disease before the incident concussion during the study period. The investigators matched three control participants to each included patient on the basis of age, sex, and location.

Study outcome was time from index date (date of first concussion) to diagnosis of ADHD, mood and anxiety disorder, dementia, or Parkinson’s disease. The researchers controlled for socioeconomic status using the Socioeconomic Factor Index, version 2 (SEFI2), and for preexisting medical conditions using the Charlson Comorbidity Index (CCI).

The study included 28,021 men (mean age, 25 years) and 19,462 women (mean age, 30 years) in the concussion group and 81,871 men (mean age, 25 years) and 57,159 women (mean age, 30 years) in the control group. Mean SEFI2 score was approximately −0.05, and mean CCI score was approximately 0.2.
 

Dose effect?

Results showed that concussion was associated with an increased risk for ADHD (hazard ratio [HR], 1.39), mood and anxiety disorder (HR, 1.72), dementia (HR, 1.72), and Parkinson’s disease (HR, 1.57).

After a concussion, the risk of developing ADHD was 28% higher and the risk of developing mood and anxiety disorder was 7% higher among women than among men. Gender was not associated with risk for dementia or Parkinson’s disease after concussion.

Sustaining a second concussion increased the strength of the association with risk for dementia compared with sustaining a single concussion (HR, 1.62). Similarly, sustaining more than three concussions increased the strength of the association with the risk for mood and anxiety disorders (HR for more than three vs one concussion, 1.22) and Parkinson›s disease (HR, 3.27).

A sensitivity analysis found similar associations between concussion and risk for mood and anxiety disorder among all age groups. Younger participants were at greater risk for ADHD, however, and older participants were at greater risk for dementia and Parkinson’s disease.

Increased awareness of concussion and the outcomes of interest, along with improved diagnostic tools, may have influenced the study’s findings, Dr. Morissette noted. “The sex-based differences may be due to either pathophysiological differences in response to concussive injuries or potentially a difference in willingness to seek medical care or share symptoms, concussion-related or otherwise, with a medical professional,” he said.

“We are hopeful that our findings will encourage practitioners to be cognizant of various conditions that may present in individuals who have previously experienced a concussion,” Dr. Morissette added. “If physicians are aware of the various associations identified following a concussion, it may lead to more thorough clinical examination at initial presentation, along with more dedicated care throughout the patient’s life.”
 

Association versus causation

Commenting on the research, Steven Erickson, MD, sports medicine specialist at Banner–University Medicine Neuroscience Institute, Phoenix, Ariz., noted that although the study showed an association between concussion and subsequent diagnosis of ADHD, anxiety, and Parkinson’s disease, “this association should not be misconstrued as causation.” He added that the study’s conclusions “are just as likely to be due to labeling theory” or a self-fulfilling prophecy.

“Patients diagnosed with ADHD, anxiety, or Parkinson’s disease may recall concussion and associate the two diagnoses; but patients who have not previously been diagnosed with a concussion cannot draw that conclusion,” said Dr. Erickson, who was not involved with the research.

Citing the apparent gender difference in the strength of the association between concussion and the outcomes of interest, Dr. Erickson noted that women are more likely to report symptoms in general “and therefore are more likely to be diagnosed with ADHD and anxiety disorders” because of differences in reporting rather than incidence of disease.

“Further research needs to be done to definitively determine a causal relationship between concussion and any psychiatric or neurologic diagnosis,” Dr. Erickson concluded.

The study was funded by the Pan Am Clinic Foundation. Dr. Morissette and Dr. Erickson have disclosed no relevant financial relationships.

A version of this article originally appeared on Medscape.com.

Concussion is associated with increased risk for subsequent development of attention-deficit/hyperactivity disorder (ADHD), as well as dementia and Parkinson’s disease, new research suggests. Results from a retrospective, population-based cohort study showed that controlling for socioeconomic status and overall health did not significantly affect this association.

The link between concussion and risk for ADHD and for mood and anxiety disorder was stronger in the women than in the men. In addition, having a history of multiple concussions strengthened the association between concussion and subsequent mood and anxiety disorder, dementia, and Parkinson’s disease compared with experiencing just one concussion.

The findings are similar to those of previous studies, noted lead author Marc P. Morissette, PhD, research assistant at the Pan Am Clinic Foundation in Winnipeg, Manitoba, Canada. “The main methodological differences separating our study from previous studies in this area is a focus on concussion-specific injuries identified from medical records and the potential for study participants to have up to 25 years of follow-up data,” said Dr. Morissette.

The findings were published online July 27 in Family Medicine and Community Health, a BMJ journal.
 

Almost 190,000 participants

Several studies have shown associations between head injury and increased risk for ADHD, depression, anxiety, Alzheimer’s disease, and Parkinson’s disease. However, many of these studies relied on self-reported medical history, included all forms of traumatic brain injury, and failed to adjust for preexisting health conditions.

An improved understanding of concussion and the risks associated with it could help physicians manage their patients’ long-term needs, the investigators noted.

In the current study, the researchers examined anonymized administrative health data collected between the periods of 1990–1991 and 2014–2015 in the Manitoba Population Research Data Repository at the Manitoba Center for Health Policy.

Eligible patients had been diagnosed with concussion in accordance with standard criteria. Participants were excluded if they had been diagnosed with dementia or Parkinson’s disease before the incident concussion during the study period. The investigators matched three control participants to each included patient on the basis of age, sex, and location.

Study outcome was time from index date (date of first concussion) to diagnosis of ADHD, mood and anxiety disorder, dementia, or Parkinson’s disease. The researchers controlled for socioeconomic status using the Socioeconomic Factor Index, version 2 (SEFI2), and for preexisting medical conditions using the Charlson Comorbidity Index (CCI).

The study included 28,021 men (mean age, 25 years) and 19,462 women (mean age, 30 years) in the concussion group and 81,871 men (mean age, 25 years) and 57,159 women (mean age, 30 years) in the control group. Mean SEFI2 score was approximately −0.05, and mean CCI score was approximately 0.2.
 

Dose effect?

Results showed that concussion was associated with an increased risk for ADHD (hazard ratio [HR], 1.39), mood and anxiety disorder (HR, 1.72), dementia (HR, 1.72), and Parkinson’s disease (HR, 1.57).

After a concussion, the risk of developing ADHD was 28% higher and the risk of developing mood and anxiety disorder was 7% higher among women than among men. Gender was not associated with risk for dementia or Parkinson’s disease after concussion.

Sustaining a second concussion increased the strength of the association with risk for dementia compared with sustaining a single concussion (HR, 1.62). Similarly, sustaining more than three concussions increased the strength of the association with the risk for mood and anxiety disorders (HR for more than three vs one concussion, 1.22) and Parkinson›s disease (HR, 3.27).

A sensitivity analysis found similar associations between concussion and risk for mood and anxiety disorder among all age groups. Younger participants were at greater risk for ADHD, however, and older participants were at greater risk for dementia and Parkinson’s disease.

Increased awareness of concussion and the outcomes of interest, along with improved diagnostic tools, may have influenced the study’s findings, Dr. Morissette noted. “The sex-based differences may be due to either pathophysiological differences in response to concussive injuries or potentially a difference in willingness to seek medical care or share symptoms, concussion-related or otherwise, with a medical professional,” he said.

“We are hopeful that our findings will encourage practitioners to be cognizant of various conditions that may present in individuals who have previously experienced a concussion,” Dr. Morissette added. “If physicians are aware of the various associations identified following a concussion, it may lead to more thorough clinical examination at initial presentation, along with more dedicated care throughout the patient’s life.”
 

Association versus causation

Commenting on the research, Steven Erickson, MD, sports medicine specialist at Banner–University Medicine Neuroscience Institute, Phoenix, Ariz., noted that although the study showed an association between concussion and subsequent diagnosis of ADHD, anxiety, and Parkinson’s disease, “this association should not be misconstrued as causation.” He added that the study’s conclusions “are just as likely to be due to labeling theory” or a self-fulfilling prophecy.

“Patients diagnosed with ADHD, anxiety, or Parkinson’s disease may recall concussion and associate the two diagnoses; but patients who have not previously been diagnosed with a concussion cannot draw that conclusion,” said Dr. Erickson, who was not involved with the research.

Citing the apparent gender difference in the strength of the association between concussion and the outcomes of interest, Dr. Erickson noted that women are more likely to report symptoms in general “and therefore are more likely to be diagnosed with ADHD and anxiety disorders” because of differences in reporting rather than incidence of disease.

“Further research needs to be done to definitively determine a causal relationship between concussion and any psychiatric or neurologic diagnosis,” Dr. Erickson concluded.

The study was funded by the Pan Am Clinic Foundation. Dr. Morissette and Dr. Erickson have disclosed no relevant financial relationships.

A version of this article originally appeared on Medscape.com.

Concussion is associated with increased risk for subsequent development of attention-deficit/hyperactivity disorder (ADHD), as well as dementia and Parkinson’s disease, new research suggests. Results from a retrospective, population-based cohort study showed that controlling for socioeconomic status and overall health did not significantly affect this association.

The link between concussion and risk for ADHD and for mood and anxiety disorder was stronger in the women than in the men. In addition, having a history of multiple concussions strengthened the association between concussion and subsequent mood and anxiety disorder, dementia, and Parkinson’s disease compared with experiencing just one concussion.

The findings are similar to those of previous studies, noted lead author Marc P. Morissette, PhD, research assistant at the Pan Am Clinic Foundation in Winnipeg, Manitoba, Canada. “The main methodological differences separating our study from previous studies in this area is a focus on concussion-specific injuries identified from medical records and the potential for study participants to have up to 25 years of follow-up data,” said Dr. Morissette.

The findings were published online July 27 in Family Medicine and Community Health, a BMJ journal.
 

Almost 190,000 participants

Several studies have shown associations between head injury and increased risk for ADHD, depression, anxiety, Alzheimer’s disease, and Parkinson’s disease. However, many of these studies relied on self-reported medical history, included all forms of traumatic brain injury, and failed to adjust for preexisting health conditions.

An improved understanding of concussion and the risks associated with it could help physicians manage their patients’ long-term needs, the investigators noted.

In the current study, the researchers examined anonymized administrative health data collected between the periods of 1990–1991 and 2014–2015 in the Manitoba Population Research Data Repository at the Manitoba Center for Health Policy.

Eligible patients had been diagnosed with concussion in accordance with standard criteria. Participants were excluded if they had been diagnosed with dementia or Parkinson’s disease before the incident concussion during the study period. The investigators matched three control participants to each included patient on the basis of age, sex, and location.

Study outcome was time from index date (date of first concussion) to diagnosis of ADHD, mood and anxiety disorder, dementia, or Parkinson’s disease. The researchers controlled for socioeconomic status using the Socioeconomic Factor Index, version 2 (SEFI2), and for preexisting medical conditions using the Charlson Comorbidity Index (CCI).

The study included 28,021 men (mean age, 25 years) and 19,462 women (mean age, 30 years) in the concussion group and 81,871 men (mean age, 25 years) and 57,159 women (mean age, 30 years) in the control group. Mean SEFI2 score was approximately −0.05, and mean CCI score was approximately 0.2.
 

Dose effect?

Results showed that concussion was associated with an increased risk for ADHD (hazard ratio [HR], 1.39), mood and anxiety disorder (HR, 1.72), dementia (HR, 1.72), and Parkinson’s disease (HR, 1.57).

After a concussion, the risk of developing ADHD was 28% higher and the risk of developing mood and anxiety disorder was 7% higher among women than among men. Gender was not associated with risk for dementia or Parkinson’s disease after concussion.

Sustaining a second concussion increased the strength of the association with risk for dementia compared with sustaining a single concussion (HR, 1.62). Similarly, sustaining more than three concussions increased the strength of the association with the risk for mood and anxiety disorders (HR for more than three vs one concussion, 1.22) and Parkinson›s disease (HR, 3.27).

A sensitivity analysis found similar associations between concussion and risk for mood and anxiety disorder among all age groups. Younger participants were at greater risk for ADHD, however, and older participants were at greater risk for dementia and Parkinson’s disease.

Increased awareness of concussion and the outcomes of interest, along with improved diagnostic tools, may have influenced the study’s findings, Dr. Morissette noted. “The sex-based differences may be due to either pathophysiological differences in response to concussive injuries or potentially a difference in willingness to seek medical care or share symptoms, concussion-related or otherwise, with a medical professional,” he said.

“We are hopeful that our findings will encourage practitioners to be cognizant of various conditions that may present in individuals who have previously experienced a concussion,” Dr. Morissette added. “If physicians are aware of the various associations identified following a concussion, it may lead to more thorough clinical examination at initial presentation, along with more dedicated care throughout the patient’s life.”
 

Association versus causation

Commenting on the research, Steven Erickson, MD, sports medicine specialist at Banner–University Medicine Neuroscience Institute, Phoenix, Ariz., noted that although the study showed an association between concussion and subsequent diagnosis of ADHD, anxiety, and Parkinson’s disease, “this association should not be misconstrued as causation.” He added that the study’s conclusions “are just as likely to be due to labeling theory” or a self-fulfilling prophecy.

“Patients diagnosed with ADHD, anxiety, or Parkinson’s disease may recall concussion and associate the two diagnoses; but patients who have not previously been diagnosed with a concussion cannot draw that conclusion,” said Dr. Erickson, who was not involved with the research.

Citing the apparent gender difference in the strength of the association between concussion and the outcomes of interest, Dr. Erickson noted that women are more likely to report symptoms in general “and therefore are more likely to be diagnosed with ADHD and anxiety disorders” because of differences in reporting rather than incidence of disease.

“Further research needs to be done to definitively determine a causal relationship between concussion and any psychiatric or neurologic diagnosis,” Dr. Erickson concluded.

The study was funded by the Pan Am Clinic Foundation. Dr. Morissette and Dr. Erickson have disclosed no relevant financial relationships.

A version of this article originally appeared on Medscape.com.