Abstracts

Lateralization of temporal lobe epilepsy (TLE) is sometimes unclear based on the non-invasive presurgical evaluation. In this situation, invasive EEG-video monitoring is performed, using either depth or subdural electrodes. We reviewed our experience with bitemporal subdural strips for lateralization of TLE., We reviewed the data on all patients who received bitemporal subdural strips for lateralization of TLE at our center from December 2000 to March 2006. We only analyzed patients whose sole question was lateralization of TLE; if non-temporal coverage was performed, patients were excluded. Outcome used Engel[apos]s classification., Over a 5-year period, 21 patients underwent bitemporal subdural strips. Out of 1,356 patients monitored, this represents 1.5% of patients.
The results for the 21 patients with bitemporal subdural strips evaluation was as follows:
[bull] 11 patients (52%) had clear lateralization (100% of seizures on one side) resulting in a temporal lobectomy: 8 class I, 2 class II, and 1 class III.
[bull] 5 patients had a predominance but less than 100% lateralization. These were offered a temporal lobectomy and presented before surgery as an unlikely seizure free outcome but a probable improvement ([quot]palliative[quot] interventions). 4 patients underwent a lobectomy (2 class III, 2 class IV), and 1 declined.
[bull] 1 patient underwent resection of a large arachnoid cyst that was contralateral to seizure onset (outcome class II).
[bull] 4 patients (19%) had true bitemporal epilepsy without predominance and no resection was performed., Subdural strips achieved lateralization of TLE in about half of cases where the non-invasive evaluation failed to do so. When lateralization was 100% to one side, postoperative outcome was excellent. About 19% had true bitemporal epilepsy.,