Relation of cortical language distribution and cognitive function in surgical epilepsy patients

Purpose: To investigate the relation between the number and spatial distribution of language sites and specific patient- and epilepsy-related variables. Methods: Patients with stimulation-induced reading or naming errors from anterior or inferior temporal cortex (i.e., atypical temporal language sites) were compared with those with language sites confined to Wernicke's area (WA) in the posterosuperior temporal and inferior parietal perisylvian area. In a consecutive series of 44 left hemisphere language dominant patients with complex partial seizures before left temporal lobectomy, correlations were compared between cortical language distribution and measures of cognitive function. Results: Patients with atypical temporal language sites (group 1) had significantly fewer years of education that did patients with language sites in WA (group 2). Patients in group 1 had poorer verbal learning and fluency than did patients in group 2. Patients with IQ <80 were significantly more likely to have multiple sites where stimulation disrupted language than did patients with normal IQ. Number of language sites had significant negative correlations with full-scale IQ, and measures of confrontation naming, verbal fluency, and immediate verbal memory. Conclusions: Language cortex has a wider spatial distribution in epilepsy surgery patients with lower intelligence, poorer education, and worse verbal and memory skills.