Repetition and the arcuate fasciculus.

According to the traditional model of language organization, repetition deficits arise following damage to the arcuate fasciculus of the dominant hemisphere (conduction aphasia). Conduction aphasia may result from lesions that spare the arcuate fasciculus. However, these patients have atypical language organization. We describe a man with normal language architecture who underwent a resection of the anterior portion of his arcuate fasciculus and retained his ability to repeat words and sentences. We propose that the arcuate fasciculus is not necessary for speech repetition by the lexical route.