Recurrence rate of the first nonfebrile seizure in children with autism spectrum disorder.

ABSTRACT

OBJECTIVE: Epilepsy prevalence is higher in children with Autism Spectrum Disorder (ASD) and is a contributor to morbidity and mortality. Little is known about the recurrence rate after the first nonfebrile seizure in this population, specifically in regard to seizure type and electroencephalogram (EEG) findings. METHODS: We reviewed pediatric medical records at our institution between 2006 and 2016 for subjects with ASD who had a first seizure. We then looked for risk of a recurrent non-provoked seizure within the next two years. RESULTS: Overall, the recurrence rate in this study was 70.9%. This is much higher than the general population. The recurrence rate was higher in patients who had a generalized convulsion compared to those who had a behavioral arrest. When the first seizure was a generalized convulsion, there was an 84% chance of developing a second convulsion, whereas the recurrence rate was 59% for behavioral arrest type seizures (p = 0.002). The odds of having recurrence when the first seizure is a generalized convulsion was 5.36 higher than when it was a behavioral arrest (95% CI 2.14-13.42, p < 0.001). An abnormal EEG was a strong predictor of seizure recurrence in both seizure types. However, even with a normal EEG, generalized convulsions were more likely to recur within 2 years compared to behavioral arrest (OR 6.3, 95% CI 2.1-19). SIGNIFICANCE: The recurrence rate for nonfebrile seizures in children with ASD is much higher than the general population, especially for generalized convulsions. An abnormal EEG has a strong predictive value for seizure recurrence. However, even when the EEG is normal, the recurrence rate for generalized convulsions is quite high. This is an important finding as epilepsy contributes to morbidity and mortality in this group and may impact clinical decisions about when to start anti-seizure medications.