EEG and neuroimaging correlations in children with lissencephaly

PURPOSE To study the usefulness of EEG in the diagnosis of lissencephaly, a rare cortical developmental disorder associated with abnormal cellular proliferation. Currently, the clinical emphasis is placed on the radiological and genetic aspects for the diagnosis of lissencephaly. METHODS This is a retrospective review of consecutive EEG recordings and imaging data from 14 children, with the diagnosis of lissencephaly, who were admitted from January 1998 to January 2010. All EEG recordings were performed with the 10-20 system of electrode placement, in both awake and sleep states. All EEG recordings were reviewed using anterior-posterior bipolar and transverse montages and then they were interpreted blindly, with respect to the imaging and genetic investigations for each patient. RESULTS All children showed one of the three characteristic EEG patterns reported in the literature of lissencephaly. The EEG pattern I, showed an anterior posterior gradient that corresponded to the severity of the imaging study abnormality. All patients were on two or more AEDs and reported to continue having active epilepsy. CONCLUSION In a child with clinical characteristics of lissencephaly, one of these three reported EEG patterns can prove useful in making the diagnosis very probable, preceding imaging and genetic testing.