Do partial seizures predict an increased risk of seizure recurrence after antiepilepsy drugs are withdrawn?

Most children who are seizure free on antiepilepsy drugs for 2 or more years remain seizure free when taken off antiepilepsy drugs. We studied 27 children with well-controlled epilepsy in whom seizures unexpectedly recurred after antiepilepsy drug withdrawal. Seizures were focal in 20 of 27 cases (74%). In 11 of the 20 cases (55%), there was also a late onset of seizures (after 2 years) and an abnormal electroencephalogram (EEG) at antiepilepsy drug withdrawal. Of the remaining 9 patients with focal seizures, 3 (15%) had only a late seizure onset, 3 (15%) had only an abnormal EEG, and 3 (15%) had neither a late onset of seizures nor an abnormal EEG. In the 7 patients without focal seizures, 6 of 7 (86%) had a late seizure onset and/or an abnormal EEG. Our study suggests that partial seizures can be the most important predictor of unanticipated seizure recurrence when antiepilepsy drugs are withdrawn, particularly with late onset of seizures and an abnormal EEG at antiepilepsy drug withdrawal. A large, multicenter, prospective study looking at these and other potential risk factors for seizure recurrence is needed.