Conference Coverage

Comorbidity rates remain stable over 10 years in childhood-onset epilepsy



The rates of medical and psychiatric comorbidity remain stable for 10 years after diagnosis in patients with childhood-onset epilepsy, according to research presented at the annual meeting of the American Epilepsy Society. Compared with controls, however, young adults with childhood-onset epilepsy have higher rates of psychiatric comorbidity.

The findings suggest that “diagnoses that are identified at baseline continue to be a problem over time,” said Jana E. Jones, PhD, associate professor of neuropsychology at the University of Wisconsin in Madison. Although neurologists understand that comorbidities are common among patients with childhood-onset epilepsy, “it would be good for us to continue to learn what factors are influencing this,” she added.

Investigators sought predictors of outcomes at 10 years

Since 2004, Dr. Jones and her colleagues at the University of Wisconsin have been conducting a study of patients with childhood-onset epilepsy. After the population had completed 10 years of follow-up, the researchers analyzed the data to identify potential patterns of medical and psychiatric comorbidities. One question that they sought to answer was whether any baseline factors could predict outcomes at 10 years.

The researchers analyzed data for 53 patients with childhood-onset epilepsy and 55 controls without epilepsy. At baseline, participants were between ages 8 years and 18 years and had no intellectual disability or neurologic impairment. Within 1 year of epilepsy diagnosis, each participant underwent a psychiatric interview based on the Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS). Ten years later, participants underwent the Composite International Diagnostic Interview (CIDI), a psychiatric interview for adults. Information about medical comorbidities was collected through interviews and record review at baseline and through an online survey at the 10-year follow-up.

Participants’ mean age at baseline was 12 years. Mean IQ was 105 for the epilepsy group and 109 for the control group. At 10 years, participants’ mean age was about 23 years. Among patients with epilepsy, 55% had focal epilepsy, and 42% had generalized epilepsy. About 40% of participants with epilepsy were in remission at 10 years, which Dr. Jones and colleagues defined as having achieved 5 years without taking medications and without having seizures. At 10 years after diagnosis, 51% of patients with epilepsy were not taking any seizure medication, including approximately 11% of patients with epilepsy who were not categorized as in remission. Most patients taking medication were on monotherapy.

Trends in psychiatric and medical comorbidities

At baseline, approximately 75% of children with epilepsy had a psychiatric or medical diagnosis, compared with 40% of controls. At the 10-year follow-up, 62% of children with epilepsy had a psychiatric diagnosis, compared with 35% of controls. Among controls, 4% had a medical comorbidity (i.e., asthma) alone at baseline. Asthma was the most common medical comorbidity at baseline among patients with epilepsy, and other comorbidities included sleep disorder, head injury, and scoliosis. Six percent of patients had a medical comorbidity alone at baseline. The proportion of patients with both psychiatric and medical comorbidity was 8% at baseline. Patients with epilepsy at baseline had an increased risk of psychiatric comorbidity.

At 10 years, the most common medical comorbidity among patients with epilepsy was head injury (18.9%), followed by allergies and asthma. The rate of migraine was about 13% among controls and slightly less in the epilepsy group. Dr. Jones and colleagues found no significant differences in medical comorbidities between groups at 10 years. At that point, the rate of medical comorbidity was 4% among patients and 11% among controls.

The rate of psychiatric comorbidity remained relatively stable over 10 years, said Dr. Jones. Approximately 47% of patients with epilepsy had a psychiatric diagnosis at 10 years, compared with 29% of controls. In addition, 38% of patients with epilepsy had both psychiatric and medical diagnoses, compared with 29% of controls. Epilepsy increased the risk of psychiatric comorbidity at the 10-year follow-up. Neither medications, remission status, nor seizure type predicted any comorbidity at 10 years.

Dr. Jones and colleagues compared comorbidity rates between the study sample and the National Comorbidity Survey Replication (NCS-R), which reported population-based data that included an epilepsy sample. About 47% of the epilepsy group had an anxiety disorder, compared with 40.7% in the NCS-R. The rate of anxiety disorders was higher in the control group (45.5%) than in the control group (30.8%) in the NCS-R. Approximately 26.4% of the population in Dr. Jones’s study had a mood disorder, compared with 25.9% in the National Comorbidity Survey.

Dr. Jones and colleagues are conducting 15-year follow-up of their original population. One question they will examine is whether medical comorbidities will increase in patients with childhood-onset epilepsy as they approach age 30 years.

Two of the investigators received funding in the form of a grant from the National Institutes of Health.

SOURCE: Kesselmayer RF et al. AES 2019. Abstract 1.288.

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