[Safety and efficacy of multiple subpial transections: report of a consecutive series of 30 cases].

PURPOSE

To present our results using multiple subpial transections (MST) for the treatment of pharmacologically refractory epilepsy (PRE) with epileptogenic foci in eloquent areas.

METHOD

Between January 2003 and March 2006, we treated 33 patients with PRE with epileptogenic foci in eloquent areas by MST "in rays", either isolated (MSTs group) or completing resection or disconnection of other cortical areas (MST+ group). Our first 30 patients had a follow-up of at least 24 months: eight in the MSTs group and 22 in the MST+ group. Four postoperative grades were distinguished based on a modified Engel classification: seizure-free (100% seizure reduction equals to Grade I), substantial significant seizure reduction (75% to 99% seizure reduction equals to Grade II), moderate significant reduction (50% to 74% seizure reduction equals to Grade III) and finally no significant reduction (seizure reduction less than 50% equals to Grade IV).

RESULTS

In the MSTs group, two patients (25%) were in grade I and five (62%) in grade II or III. In the MST+ group, six patients (27%) were in grade I and 13 (59%) in grade II or III. All patients showed some seizure reduction and some improvement in behavior or cognitive function with no permanent neurological deficit.

CONCLUSION

This series supports the notion that multiple subpial transections are associated with a significant seizure reduction (in 86.6% of the cases reported herein) and that the risk of permanent neurological deficit can be very low.