Right-hemisphere language dominance in temporal lobe epilepsy: clinical and neuropsychological correlates.

Prior to and following temporal lobe surgery, patients with right-hemisphere language dominance and focal left temporal lobe epilepsy (RHLD-LTLSz) were compared to right-handed patients with left-hemisphere language dominance and either left temporal lobe epilepsy (LHLD-LTLSz) or right temporal lobe epilepsy (LHLD-RTLSz). The group of RHLD-LTLSz patients had a more consistent history of brain involvement before the age of 5 years and had a higher seizure frequency rating than did either LHLD patient group. Cognitively, RHLD-LTLSz patients did not show significant deficits in psychometric intellectural scores. In addition, they did not demonstrate comparable degrees of verbal memory loss as found either pre- or postoperatively in LHLD-LTLSz patients. The right-handed RHLD-LTLSz and the right-handed LHLD-LTLSz groups both appeared to exhibit bilaterally depressed fine-motor coordination. The left-handed RHLD-LTLSz patients did not show the same motor deficiencies. These latter findings suggest that hemispheric dominance for bilateral motor control may exist independent of language dominance, but not independent of handedness.