Long-term prognosis of epilepsy in patients with cerebral palsy

Aim To assess the long-term natural course and prognosis of epilepsy in patients with cerebral palsy (CP). Method We retrospectively collected data for 72 patients (36 males, 36 females) with CP who had epilepsy who visited our institutions between 1980 and 2015. The data from medical records, electroencephalography (EEG), and neuroimaging findings were reviewed. Time-to-event statistical analyses were performed to analyse the remission outcome and the Cox regression model was used for multivariate analyses. Results Median age at onset of epilepsy was 2 years 0 months, and 17 years 0 months at the latest follow-up. In total, 34 patients (47%, 0.043 per person-year) achieved seizure remission at a median age of 11 years 0 months. Favourable factors for seizure remission included older age, motor disability being able to roll over/crawl but not able to sit, intellectual disability with an IQ between 36 and 70, normal findings on neuroimaging, and CP type other than spastic quadriplegia. In multivariate analysis, spastic quadriplegia was found to be associated with continued seizure activity. Antiepileptic drugs could be discontinued without relapse in 10 patients at a median age of 16 years 6 months, occurring 11 years 6 months after the onset of epilepsy. The drugs were terminated if the patient was aged at least 10 years and had perinatal causative aetiology and normalization or amelioration of epileptiform discharges on EEG. Interpretation The remission rate of epilepsy in CP increases up to young adulthood, and termination of antiepileptic drugs can be considered in selected cases at older ages. What this paper adds The remission rate of epilepsy in cerebral palsy increases up to 20 years after onset. In some cases, antiepileptic drugs (AEDs) can be terminated without relapse. Older age, perinatal aetiology, and improvement on electroencephalography are favourable factors for terminating AEDs.