Preoperative memory profiles in patients with temporal lobe epilepsy are related to postoperative seizure outcome

Abstract

The relationship between the degree and bitemporal extension of preoperative memory deficits and postoperative seizure outcome was examined among 26 left (LTE) and 26 right (RTE) temporal lobectomy patients. Both groups were balanced with respect to the seizure outcome 3 months postoperatively. The evaluation was based on measures of verbal and visuospatial memory, which had been proved to reveal the best discrimination of left from right temporal deficits in previous studies. The following results were obtained. (a) Presurgically, LTE patients primarily suffered from verbal memory deficits and RTE patients from visuospatial memory deficits. (b) With respect to the side of surgery, patients who did not become seizure-free had shown significantly poorer contralateral memory performance preoperatively than seizure-free patients. Additionally, they tended to exhibit poorer ipsilateral memory performance. (c) The best seizure outcome was observed in completely unimpaired patients preoperatively, followed by patients with deficits restricted to either verbal or visual memory. Most of the patients who showed both verbal and visual memory deficits preoperatively did not become seizure-free. In conclusion, presurgical memory profiles appear to indicate the degree and bilateral extension of epilepsy-related malfunctions and can serve as a predictor of the postsurgical seizure outcome.