Abstracts

To analyze the postoperative outcome of resective epilepsy surgery among adult patients with low IQ. In order to identify all operated adult patients with low IQ, we analyzed retrospectively all adult patients who had undergone resective epilepsy surgery at Kuopio University Hospital between 1988 and 2003. Altogether 255 resective procedures for 239 adults had been performed during the study period. For the purpose of the study low IQ was defined as preoperative full scale IQ (FSIQ) [le] 70. A total of 206 patients (86%) had preoperative neuropsychological data available and 11 patients (five female, six male) with low IQ were identified (median FSIQ 67, range 43-70) among them. Additionally, one patient was included without formal preoperative neuropsychological evaluation. Mean age of the patients at the time of operation was 30[plusmn] 8 (range 16-46) years and mean duration of epilepsy was 25[plusmn] 9 (range 10-49) years. Median preoperative seizure frequency was 86 seizures (range 12-2646) per year. Probable etiologies for mental retardation were malformation of cortical development (n=4), CNS-infection (n=3), asphyxia (n=1) and fragile-X (n=1). In three patients no specific etiology was identified. Resective procedures included eight temporal resections (three selective amygdalohippocampectomies), two extratemporal resections, one multilobar resection, and one functional hemisferotomy. Three patients were reoperated. The operation was defined as curative in six patients and palliative in six patients. The mean postoperative follow up was 3.3[plusmn] 5.1 (range 1.0-6.1) years. 50% of the patients became seizure-free (Engel[acute]s class I, n=6) and 25% had an 80% seizure reduction (Engel[acute]s class III, n=3). 25% of the patients (n=3) did not have significant postoperative seizure reduction. The outcome was expectedly better in curative patients and in patients with temporal lobe resections. Additionally, only one reoperation resulted in seizure reduction. Minor complications were identified in five patients. Relatively few patients with low IQ were identified among the study population. However, resective surgery was found successful in most patients with low IQ, including the palliatively operated patients. (Supported by The Finnish Cultural Foundation, Finnish Medical Society Duodecim, Finnish Neurological Society, Kuopio University Hospital Research Fund (EVO grant 5178/ 5772719), University of Kuopio, and Vaajasalo Foundation.)