Risk for seizure relapse in children with epilepsy linked to younger age at diagnosis

In children with epilepsy who discontinue anti-seizure medications, the risk for seizure relapse was significantly associated with younger age at diagnosis, according to a study published in Epilepsy & Behavior.

“Epilepsy is an extremely heterogeneous disorder. The clinical characteristics, etiology, radiological findings, the severity of disease and treatment vary from patient to patient,” Miraç Yildirim, MD, of the department of pediatric neurology at Ankara University in Turkey, and colleagues wrote. “Additionally, the prediction of the risk of seizure relapse after [anti-seizure medication] withdrawal in seizure-free patients following treatment is challenging.”

Yildirim and colleagues sought to determine predictors of seizure relapse, calculate the rate of relapse and explore long-term seizure outcomes in children with epilepsy who discontinued their antiseizure medication (ASM).

The retrospective study included 269 seizure-free children (58.4% boys; mean age at first seizure, 5.5 years) at a tertiary university hospital between January 2010 and June 2020. All participants were diagnosed with epilepsy before aged 18 years, had discontinued their ASMs and were monitored for at least 18 months after ASM withdrawal. Researchers performed univariate and multivariate analyses with logistic regression to evaluate risk factors for seizure relapse.

Results showed that children were followed up for a median of 46 months following ASM withdrawal, and 90 (33.5%) participants experienced seizure relapse (median time to relapse, 8 months). Of those 90 children, seizure relapse occurred at 1 month in 16.7%, at 6 months in 45.6%, at 1 year in 62.2%, at 2 years in 74.4%, and at 5 years in 94.4%.

Researchers identified age at first seizure, age at diagnosis of epilepsy, intellectual disability, electroencephalogram findings after ASM withdrawal, ASM tapering time and number of seizures on ASM as predictors with significant correlation to relapse, per univariate regression analyses.

However, in multivariate logistic regression analyses, age at first seizure, intellectual disability and ASM tapering time were no longer significantly associated, while the remaining three factors remained independently predictive.

Further, control of seizures was restored in 93.3% of the children with resumption of monotherapy, and only 6.7% of children needed at least two ASMs to regain seizure control.

“We suggest that these results may help the physician to predict the risk factors for seizure relapse after ASM withdrawal in pediatric population,” Yildirim and colleagues wrote.