Executive system dysfunction in temporal lobe epilepsy: effects of nociferous cortex versus hippocampal pathology.

This investigation contrasted two hypotheses regarding executive system dysfunction in temporal lobe epilepsy. The nociferous cortex hypothesis posits that epileptogenic cortex adversely affects the extratemporal regions that mediate executive system abilities, thereby resulting in performance deficits. The hippocampal hypothesis suggests that such impairments are due to the fact that the human hippocampi are directly involved in the mediation of some executive system functions and performance deficits are therefore directly attributable to hippocampal pathology. Seventy-four patients who underwent anterior temporal lobectomy were administered the Wisconsin Card Sorting Test preoperatively and approximately 6 months postoperatively. Presence or absence of hippocampal sclerosis was determined by histopathological analysis. Three specific and contrasting predictions were tested and in each instance the findings supported the nociferous cortex hypothesis.