ICTAL MEG-EEG ANALYSIS IN PATIENTS WITH CHILDHOOD-ONSET EPILEPTIC SYNDROME

Objectives: To clarify the neurophysiological mechanism of epileptic seizures in patients with various childhood-onset epileptic syndromes including pattern sensitive epilepsy (PSE), temporal lobe epilepsy (TLE), childhood absence (CA) and myoclonic astatic epilepsy (MAE) and atypical benign partial epilepsy (ABPE) with negative myoclonus.

Methods: Polygraphic recordings of whole-head type magnetoencephalography (MEG) and EEG were made during epileptic seizures without motion artifact. Single equivalent current dipoles (ECD) were calculated for each spike component associated with epileptic seizures and the estimated generator sources of spikes were superimposed on the patients' head MRI.

Results: The calculated current generators were as follows; the right visual to parietal cortex in PSE, the left temporal cortex in TLE, the perilorandic, frontal and parietal cortex in 3 CA patients, bilateral premotor cortex in MAE and the lower precentral cortex in negative myoclonus in ABPE.

Conclusion: Because body movements usually make it impossible to record precise and stable magnetic fields, ictal MEG-EEG recording is difficult to use for clinical application. However, ictal MEG-EEG analysis is sometimes informative to elucidate the pathophysiology of epileptic seizures in patients with various childhood-onset epileptic syndromes.