Voice and Speech Abnormalities in Parkinson Disease: Relation to Severity of Motor Impairment, Duration of Disease, Medication, Depression, Gender, and Age

Two experienced speech pathologists perceptually judged recordings of the "Rainbow Passage" for the presence or absence of voice, articulation, prosody, and fluency abnormalities in 42 individuals with idiopathic Parkinson disease (IPD), all medicated for their disease. The prevalence of these abnormalities was then examined with respect to (a) severity of motor impairment, measured by the Unified Parkinson's Disease Rating Scale (UPDRS), section III; (b) disease duration; (c) depression, measured by the Montgomery Asberg Depression Rating Scale (MADRS); (d) age; and (e) gender. Six individuals (14.3%) were judged free of voice and speech abnormalities. All others (85.7%) had an abnormal voice, either alone (28%) or in combination with abnormal articulation (58%), fluency (39%), or prosody (39%). Abnormal voice was prevalent even in individuals with short duration of IPD and low UPDRS scores. Individuals with high UPDRS scores and/or long duration of IPD tended to have significantly more voice and speech abnormalities than individuals with lower UPDRS scores and/or shorter duration of IPD (p < 0.0001). This difference was related primarily to abnormalities in articulation and fluency. Voice and speech abnormalities did not correlate with depression, age, or gender. These findings are discussed with respect to the etiology of dysarthria in IPD.