Stuttering: an investigation into cerebral dominance for speech.

Over the past decade research has suggested that stutterers have bilateral cerebral motor or auditory speech areas. Three typical adult stutterers showed normal unilateral left cerebral dominance for speech on the intracarotid sodium amylobarbitone (amytal) test, but one 'dysphatic' stutterer had bilateral cortical speech representation. The latter is a very rare finding in right handed individuals and presumably is a consequence of the head injury induced aphasia that preceded the onset of stuttering.