Abstracts

Rationale: Candidates for left temporal lobectomy undergo a careful selection process. Within this selected group, however, prediction of excellent seizure outcome may be attenuated due to selection-induced restriction of range and group homogeneity. Verbal memory decline on the Wechsler Memory Scale Logical Memory test (LM) is common despite careful patient selection. Postoperative neuropsychological memory assessment may be associated with prognosis for long-term seizure control after left temporal lobectomy. Methods: One-hundred twelve (112) patients without lesions other than mesial temporal sclerosis underwent left temporal lobectomy for refractory epilepsy and later responded to a survey an average of approximately 5 years after surgery. Neuropsychological evaluation was completed before and an average of approximately four (4) months after left temporal lobectomy. Results: Seventy-nine patients had excellent seizure control approximately 5 years after surgery. Forty-one of these patients had no change or improvement in their postoperative LM performance while only 6 patients with poor seizure control had no change or improvement in postoperative LM. Thirty-eight (38) patients with excellent seizure control had a decline in LM as did 27 patients with poor postoperative seizure control. Eighty-seven percent (87%) of patients with stable to improved Wechsler Memory Scale-Revised Logical Memory (LM) performance four months after surgery had excellent seizure control approximately 5 years after left temporal lobectomy (Chi-square = 10.8, p = .001, df = 1). Conclusions: Verbal memory improvement approximately four months after left temporal lobectomy predicts good long-term seizure control. These data also highlight the value of postoperative neuropsychological assessment. Even small changes in an individual patient’s memory may have prognostic significance.