Investigation of apraxia of speech and linguistic dysprosody following acute ischaemic hemispheral stroke

Abstract

Apraxia of speech (AOS) is a disorder of motor speech programming. Affected patients typically have hesitant, groping speech with impaired prosody. Automatic speech is relatively well preserved compared to propositional speech. There is little data on frequency of AOS following stroke. There are suggestions, however, that when it occurs following stroke, AOS may show rapid improvement. Linguistic prosody encompasses the use of pitch, loudness and length to produce emphasis and signal and interpret linguistic information. Traditionally prosody was thought to be mediated by the right hemisphere; however, the occurrence of dysprosody in patients with AOS (which is almost invariably caused by left hemisphere lesions) suggests a role for the left hemisphere in prosody.