Subtemporal amygdalohippocampectomy prevents verbal memory impairment in the language-dominant hemisphere

In this report, we show the operative and neuropsychological results for 20 patients with medically intractable nonlesional temporal lobe epilepsy treated surgically by subtemporal amygdalohippocampectomy whose mean postoperative follow-up period was more than 6 years.

Pre- and postoperative Wechsler Adult Intelligence Scale-Revised (WAIS/-R) scores, including verbal intelligence quotient (VIQ), performance IQ (PIQ) and full-scale IQ (FIQ) scores, were determined in the 19 adults. The revised Wechsler Intelligent Scale for Children was used in a 9-year-old boy. The verbal paired associates learning test was performed pre- and postoperatively in 15 patients. These data were compared pre- and postoperatively in 10 patients in whom the language-dominant hemisphere side was operated on, and in 5 patients in whom the language-non-dominant side was operated on.

Seizure control was achieved in 80% of patients, with improvement into Engel categories I and II without definite permanent complications except for postoperative memory impairment in one patient. VIQ improved after 2 years, and PIQ and FIQ improved after both 2 months and 2 years postoperatively.

There was no significant decline in the postoperative verbal memory scores in those patients whose medial temporal structure of the language-dominant side had been removed.