Drug withdrawal in patients with epilepsy: prognostic value of the EEG.

The role of the inter-ictal EEG in predicting seizure relapse after antiepileptic drug withdrawal (AED-W) is unclear. A prospective study on AED-W is in progress. This trial includes routine and sleep EEG recordings every 3 and 6 months, respectively, at each step of the drug discontinuation and periodically during follow-up. Data obtained for 136 patients (mean age 23.2 years; 63 with Idiopathic Generalized Epilepsy IGE, 73 with Partial Cryptogenic or Symptomatic Epilepsy PE; without associated neuropsychiatric handicap; with at least 1 year of follow-up after AED-W) were analysed. EEG recordings from seizure onset were available for all patients. Data were analysed separately in IGE and PE patients. The presence of inter-ictal epileptiform abnormalities (IEAs) at the seizure onset and just before AED-W does not seem to predict the AED-W outcome. However, results indicate an association between persisting and increased IEAs during AED-W and a higher relapse rate in both groups, which was statistically significant in the IGE patients.