The determination of speech organization in a patient with an arteriovenous malformation.

A case is reported of an arteriovenous malformation in the left motor speech area which was successfully excised without aphasia in a right-handed man. Preoperative sodium amobarbital carotid infusion testing demonstrated that the patient had right hemisphere dominance for speech. A review of the literature suggests that this is not an uncommon occurrence in individuals with congenital lesions of the left cerebral hemisphere. Lateralization of speech dominance should be established through definitive testing in these cases, especially if surgical removal of the malformation is contemplated.