STEREO-EEG OF INTERICTAL AND ICTAL ELECTRICAL-ACTIVITY OF A HISTOLOGICALLY PROVED HETEROTOPIC GRAY-MATTER ASSOCIATED WITH PARTIAL EPILEPSY

Magnetic resonance imaging allows the identification of heterotopic gr ay matter (HGM) in medically intractable partial epilepsies. The relat ionships between HGM and the epileptogenic zone remain, however, uncle ar. In a case of a temporo-parietal epilepsy studied by stereo-EEG, in terictal and ictal electrical activity of a temporal HGM were recorded , showing: (1) an intralesional electrical activity, (2) the possible presence of asynchronous spikes, and (3) an early but never initial, o r isolated, involvement during ictal discharges. This suggests that th e presurgical and surgical management of HGM must be guided, as for ot her lesions, by the coherence existing between ictal clinical and elec trical features, and anatomical data.