Speech dysfunction in early Parkinson's disease

The purpose of this study is to determine if subjects in the early stages of untreated Parkinson's disease (PD) or PD treated with deprenyl alone suffer from motor speech abnormalities. Speech defects are common in advanced PD, including distrubances of respiration, phonation, and articulation. We studied 12 subjects with early PD (Hoehn and Yahr stage ≤2, mean duration disease 3.2 years) who were not taking symptomatic therapy and tested them under two conditions: on and off deprenyl. None of the subjects was depressed or demented (Mini Mental Status mean 29.9/30; Hamilton Depression Rating mean 2.7/52). All functioned independently (Schwab and England Activities of Daily Living mean 93.1/100). Acoustic and speech productions were assessed using the DSP Sona-Graph 5500 and an evaluation of dysarthria. All 12 had at least two characteristics of dysarthria on examination, although 8 were not aware of it. Vocal tremor was identified on narrow band spectrogram for four subjects. Deprenyl did not have a consistent effect on speech. Ten subjects had no detectable change in speech on deprenyl, one was worse, and one was improved.