Vocal fold paresis in Shy-Drager syndrome

Twelve patients with Shy-Drager syndrome (SDS) presenting symptoms of multiple nervous system atrophy and orthostatic hypotension were examined for laryngeal movement disorders and vocal impairment in speech. Vocal fold abductor paresis was found in 11 patients and was bilateral in 10. Speech task performance was recorded in SDS patients, Parkinson patients and age- and sex-matched controls. Trained listeners with inter-rated reliability greater than or equal to .85 judged each recording on 20 attributes while blind to speaker identity. SDS patients had a breathy and strained voice quality, reduced loudness, monopitch and monoloudness, imprecise consonants, variations in rate and rate-slowing, suggesting a flaccid type of dysarthria. In comparison with Parkinson patients, SDS patients had excess vocal hoarseness, intermittent glottal fry and a slow and deliberate speaking rate. Orthostatic hypotension, laryngeal stridor, hoarseness, intermittent glottal fry and slow speech rate were found to be discriminating symptoms of SDS.