Speech motor control from its impairment: the relevance of studying dysarthria in Parkinson’s disease

Abstract

Dysarthria is a collective name for a group of neurologic motor speech disorders, resulting from central and/or peripheral nervous system abnormalities. Hypokinetic dysarthria in Parkinson's disease presents with prosodic insufficiency, related to a monotony of pitch and intensity, a reduction of accentuation, variable speech rate and possible phoneme imprecision. In most cases, the voice is harsh and breathy. Many patients complain about speech impairments, which affect their communication in daily living activities. There is still a need for further research of dysarthria in Parkinson's disease, for a better understanding of its pathophysiology, treatment response, and relationship with other functions/symptoms. The aim of this paper is to provide an insight into the investigation of dysarthria in Parkinson's disease from two complementary perspectives: from a clinical perspective, to help design patient individualised management; from a neurolinguistics point of view, to help better understand the relative contribution of basal ganglia in speech motor control.