Memory Outcome After Selective Amygdalohippocampectomy in Patients with Temporal Lobe Epilepsy: One-year Follow-up

Purpose: In a previous study we reported clinically significant memory declines 3 months after selective amygdalohippocampectomy (SAH) in 140 patients with mesial temporal lobe epilepsy, particularly if the resection was left-sided. We supposed that the observed postoperative impairments might have reflected acute effects of surgery. Therefore we evaluated in the present study whether a recovery can be found 1 year after surgery.

Methods: Verbal and nonverbal memory functions were assessed in 115 patients before and 3 and 12 months after unilateral SAH.

Results: No recovery of postoperative verbal memory declines was found in the left-SAH group. Clinically meaningful losses were still evident in 33 to 50% of patients. In right-SAH patients, a recovery of verbal memory was indicated, and effects of surgical complications were no longer evident. One year after surgery, the corresponding preoperative performance was the only significant predictor of a postoperative change in the left-SAH group.

Conclusions: Verbal memory decline observed 3 months after left SAH is persistent 1 year after surgery. Declines in verbal memory, which were observed in some right-SAH patients at the short-term follow-up, seem to be temporary.