Hemispheric specialization in children with unilateral epileptic focus, with and without computed tomography-demonstrated lesion

We evaluated 24 testable children with unilateral epileptic foci, with and without radiologically demonstrable lesions, to determine if the normal pattern of cerebral dominance is changed by the presence of an epileptic focus. Verbal and figural stimuli were presented tachistoscopically to the right and left visual hemifields to investigate the specific abilities of the two hemispheres. Three blocks of stimuli consisting of two-letter patterns, three-letter patterns, and meaningful two-syllable words were used as verbal stimuli to assess the abilities of the left hemisphere. A test consisting of localizing a dot on a 3 x 3 matrix was used to assess the abilities of the right hemisphere. Six normal children were chosen as controls. In all groups, specialization of the epileptic hemisphere was lost. The presence or absence of a radiologically demonstrable lesion did not influence this pattern.