Preserved memory in temporal lobe epilepsy patients after surgery for low-grade tumour. A pilot study.

The objective was to carry out a pilot study exploring memory outcome in patients with temporal lobe epilepsy (TLE) and low-grade tumour. A prospective study using a competence-related memory assessment was carried out in the Laboratory of Neuropsychology, Epilepsy Center and Neurosurgical Department of the "C. Besta" National Neurological Institute in 24 TLE patients undergoing surgical resection for left (n=12) or right (n=12) low-grade tumours and 36 healthy subjects. Patients underwent mesial or lateral temporal lobe lesionectomy. Neuropsychological tests exploring verbal and visual short-term memory, learning, delayed recall and ability to control interference in memory were applied. Before and after surgery, significant verbal impairment was present in left TLE patients compared to controls and right TLE patients, and visual deficits were present in both groups compared to controls. After surgery, there was no significant decrease in mean verbal or visual memory scores related to the operated side. Some memory abilities subserved by the contralateral temporal lobe improved. Postoperative memory scores were related to preoperative scores, side of operation, age and education. In patients with TLE and low-grade tumour, temporal lobe surgery does not necessarily induce memory deficits. Improvement of memory abilities subserved by the unoperated temporal lobe may be expected.