Among 127 patients with autism who had experienced at least one seizure, the epilepsy was treatment resistant in 33.9%, according to Orrin Devinsky, MD, and colleagues from New York University in New York City.
Seizure onset was earlier, at an average age of 5.9 years, among patients with treatment-resistant epilepsy compared with patients who had been seizure-free for at least one year and whose average age of onset was at 10.9 years (P=0.008), the researchers reported online in Epilepsia.
Autism has been linked to an increased risk of epilepsy, with a reported prevalence between 7% and 46%, and is associated with more profound intellectual impairment and regression in cognitive development. But the true prevalence of epilepsy in autistic patients is uncertain, because studies examining this typically have included comorbid conditions such as fragile X syndrome.
In addition, the prevalence of treatment-resistant seizures in these patients and their treatment outcomes are unknown.
Devinsky's group reviewed the charts of all patients referred to their tertiary care epilepsy center between 1989 and 2009.
The cohort included 96 males and 31 females whose mean age was 16.5 years. Mean age at seizure onset among the entire group was 8.2 years