Right-hemisphere language dominance in right-handed epileptic patients
R. Rausch and G. O. Walsh
Hemispheric language dominance, as determined by intracarotid amobarbital
sodium injections, and handedness, as reflected by writing and drawing
preference, were evaluated in a select group of patients with intractable
seizures who had documented focal epilepsy originating from one temporal
lobe. Of the patients with left temporal lobe seizure focus, an unusually
high percentage of right-handed patients (4/26 [15%]) had right hemisphere
language dominance. Pathologic findings of the resected temporal lobe in
these patients revealed microscopic damage (hippocampal sclerosis) of the
hippocampus in three of three cases; one patient also had a small hamartoma
in the midtemporal gyrus. We hypothesize that crossed dominance resulted
from disruption by epileptiform activity during early development of
selective areas of the left hemisphere.
