Music perception can be affected by lesions in the cerebral cortex. Despite its proven effectiveness in eliminating or reducing seizures, temporal lobe epilepsy surgery might have a danger of postoperative functional deficit. Several studies reported postoperative impairment in musical processing for patients who underwent right temporal lobe surgery. In the present study, we investigated the effect of surgical treatment on cognitive and music functions in subjects with right temporal lobe epilepsy (TLE) who possessed a rare ability of absolute pitch (AP).

Twenty patients with right mesial TLE in our epilepsy surgery program were enrolled in the study. Two of them were confirmed to possess AP by a pitch naming test using 40 piano tones and 40 sine wave tones. In all subjects, preoperative cognitive functions were measured by neuropsychological tests including WAIS-R/III and WMS-R and the dominant hemisphere for language was evaluated by intracarotid propofol test (Wada test). All subjects underwent selective amygdalohippocampectomy in the right side. The AP ability of the two AP possessors was evaluated in a follow-up postoperative examination. Preoperative cognitive test scores were compared between AP and non-AP subjects. Part of 2-year postoperative cognitive changes was also analyzed.

The ability of AP was preserved postoperatively in the two AP subjects. The dominant hemisphere for language was the left in one AP subject and bilateral in the other. In all non-AP subjects the dominant hemisphere for language was the left. In the preoperative evaluation of cognitive functions, the AP subjects scored significantly lower on Spatial Span subtest in WMS-R, while other scores showed no significant difference from those of non-AP group mean. The Spatial Span Subtest score of AP subject improved postoperatively. Different from reports in the literature, the AP ability was preserved after epilepsy surgery of right selective amygdalohippocampectomy in the present study and some cognitive functions improved.