Abstract
We performed intracarotid amobarbital tests on 430 patients who were being evaluated for epilepsy surgery in our hospital. There were 46 patients who had right hemisphere language dominance. The side of epileptogenic focus, handedness, family history of sinistrality, etiology of epilepsy, and performance of neuropsychological testing were examined. Twenty-seven patients had left-sided epileptogenic focus, 14 had right-sided focus and 5 had bilateral or undetermined side of epileptogenicity. Twenty-four patients were dextral, 22 patients were ambidextral or sinistral. There were 17 patients who had family members with sinistrality. The occurrence of right hemisphere language dominance was not correlated with a family history of sinistrality. Among the patients who underwent surgery and were histopathologically examined, all had evidence of brain damage or congenital abnormality. The right language dominance may result from a secondary shifting from left to right hemisphere. Neuropsychological testing revealed that the performance of tests of memory and verbal function in patients with left epileptogenic focus was lower than that of patients with right epileptogenic focus. Brain damage that inevitably resulted in a right language dominance may be more serious in patients with left epileptogenic focus than those with right epileptogenic focus.
