Value of intracranial EEG recording for localizing epileptogenic zone in refractory temporal lobe epilepsy

Objective: To explore the role of long-term intracranial EEG recording in patient with refractory temporal lobe epilepsy for localizing epileptogenic zone. Methods: twenty refractory temporal lobe epilepsy, whose seizure onsets were unable to be localized with MRI,scalp EEG recording and clinical characteristic, Accepted long-term intracranial EEG monitoring to record the ictal and interictal EEG monitoring under the guiding of the stereotactic technique, The results from routine EEG and cortical electrode EEG were compared. The accuracy for localization of epilepitogenic zone was evaluated based on the clinical follow-up. Results: The intracraniai electrode EEG monitoring was implanted within 1~5days. Each patient was recorded the ictal and interictal discharge and was detected clinical onsets at least two times. All patients can be localized by ictal EEG. The consistency between interical EEG and ictal EEG was seen in 15 cases, and the inconsistency was in 3 cases, and 2 cases were bilateral discharge in interictal. The clinical outcome showed that patients were seizure-free in 13 cases (65%), improved significantly in 3 cases (15%), improved in 3 cases (15%), unimproved in 1 case (5%) according to Engel's criteria after surgery. For all patients, no significant complication was found. Conclusions: lntracranial EEG recording, especially ictal recording in the initial stage of seizure is effective for precise epileptogenic zone localization in patients with refractory epilepsy and can offer reliable evidence for surgery.