[Cerebral lateralization in two cases of crossed dextral aphasia with right-hemisphere arteriovenous malformation]

This paper reports two cases of crossed dextral aphasia. The first patient was a 60-year-old right-handed male with no family history of sinistrality. He experienced sudden onset of left hemiplegia and loss of consciousness. A CT scan showed high-density area in the right fronto-parietal region. An angiography revealed an arteriovenous malformation (AVM) in the right parietal lobe. It was fed by a branch of the middle cerebral artery and drained through a cortical vein. Neuropsychological examination one week after the surgery showed severe defects of all language moderalities. He was alert and cooperative, but completely mute. He recognized common words by auditory and visual stimuli, but could not perform simple command. He wrote some meaningless letters when asked to write his own name. Auditory and reading comprehension gradually improved thereafter, but Broca's type of aphasia with non-fluent hesitant and effortful output was still present four months after the surgery. The second patient was a 38-year-old right-handed male. All members of this family are right-handed except for one sister who is left-handed. He suddenly suffered left hemiparesis and loss of consciousness. A CT scan disclosed a right parietal intracerebral hematoma. And an AVM which was fed by the angular artery and drained through a cortical vein was angiographically demonstrated in the same area. Postoperatively the left hemiparesis rapidly disappeared, but left homonymous hemianopsia and anomic type of aphasia still persisted. His speech was fluent and daily communication was possible in spite of circumlocutory paraphasic output.(ABSTRACT TRUNCATED AT 250 WORDS)