Discontinuance of antiepileptic medications in patients with developmental disability and diagnosis of epilepsy.

Fifty patients with developmental disabilities and past history of epilepsy but without reported seizures fo several years underwent trial reductions of an antiepileptic drug. After an 8-year follow-up there was recurrence of seizures in 26 patients. Predictors for a seizure free state off medication were: few documented seizures in lifetime, no gross neurological abnormalities, medication below therapeutic levels at time of discontinuance, and persistently normal EEGs before and after discontinuance. Successful withdrawal of medication may have resulted from early control of seizures or early treatment; lack of actual epileptic seizures but presence of "pseudoseizures"; isolated event seizures; or seizures that could have resulted from nonepileptic, self-limiting factors.