Late seizure recurrence after multiple subpial transections.

We studied long-term outcome (range, 28-89 months; mean, 56 months) after multiple subpial transections (MST) for medically refractory epilepsy. Forty-three (79.6%) of 54 patients had a consistent significant reduction in seizure frequency, and 27 (50%) of the 54 were either entirely seizure free or virtually so. However, 10 (18.5%) patients sustained an increase in seizure frequency several years after surgery, after showing initial postoperative improvement. This suggests that late seizure recurrence is a more important problem in cases in which MST has been performed than for pure resections.