Are the seizures under control or unnoticed? Electroclinical evaluation of epilepsy with eyelid myoclonia

Abstract

PurposeIn this study, patients with epilepsy with eyelid myoclonia (E-EM) were evaluated according to their EEG findings, seizure outcomes, and their consistency with the final ictal EEG findings. We also investigated the possible prognostic factors. MethodsPatients with E-EM and at least two years of follow-up in our clinic were included in the study. We analyzed the presence of eyelid myoclonia, absence and myoclonic seizures, and generalized tonic-clonic seizures for the prior two years and then verified with the latest ictal EEG features. Video-EEGs were analyzed according to the background activity, the existence of generalized spike-wave discharge or polyspike-wave complexes, focal spike-wave discharge, photoparoxysmal responses, and fast activity. Results21 patients were involved in this study. In six patients, the seizures were undetected on the first EEGs, whereas they were detected on subsequent ones. The seizures were captured on the first EEGs of six patients; however, they disappeared on subsequent ones. Only one patient had seizures detected on every EEG. The consistency of the seizures was variable in eight patients. At the final follow-up, seizures were reported as being under control for more than two years in 12 patients, according to patients and their parents’ reports. However, ictal EEG findings were detected in six of these patients. No electroclinical feature was associated with seizure freedom. ConclusionThis study provides further evidence that seizure freedom in E-EM patients is overestimated. The patients and their parents may not be aware of the seizures. Therefore, video-EEG monitorization is essential during follow-up.