Analysis of voice impairment in aphasia after stroke-underlying neuroanatomical substrates

Phonation is a fundamental feature of human communication. Control of phonation in the context of speech-language disturbances has traditionally been considered a characteristic of lesions to subcortical structures and pathways. Evidence suggests however, that cortical lesions may also implicate phonation. We carried out acoustic and perceptual analyses of the phonation of /a/ in 60 males with aphasia (20 Wernicke's, 20 Broca's, 20 subcortical aphasia) and 20 males matched in age with no neurological or speech-language disturbances. All groups with aphasia were significantly more impaired on the majority of acoustic and perceptual measures as compared with the control speakers. Within the subjects with aphasia, subjects with subcortical aphasia were more impaired on most measures compared to subjects with Broca's aphasia, and they, in turn, more impaired than those with Wernicke's aphasia. Lesions in regions involved in sound production-perception result in dysfunction of the entire neurocognitive system of articulation-phonological language processing.