Interhemispheric interactions analyzed by coherence during flexor spasms

Objective: We used coherence analysis to test for leading discharges on an ipsilateral right mesial temporal lesion in a 5 year old boy with flexor sp asms. Method: Digital EEG analysis with video-EEG telemetry was performed prepara tory to epilepsy surgery. Results: Study of 10 spasms with head drop and subsequent flexion of both a rms demonstrated an interhemispheric time lag with secondary bilateral sync hrony, with a mean difference of 17 ms. The right hemisphere led. After a l esionectomy with resection of epileptic regions (performed with electrocort icographical guidance), the patient has been seizure-free for 4 years. Path ology confirmed a low-grade mixed glioma and cortical dysgenesis. Conclusion: The coherence analysis demonstrated a pathway of secondary gene ralization, confirming that the lesional side was leading during ictal gene ralized discharges in flexor spasms. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.