Evidence for an apparent sensory speech disorder in Parkinson's disease.

Twenty eight patients with Parkinson's disease (average age 63 years, average duration of disease 8 years) and 28 normal elderly controls (average age 70 years) were tested for their ability to appreciate the prosodic aspects of their own and others' speech and facial expression. Compared with the controls the Parkinsonian subjects performed worse at these tests, though both groups could easily identify neutral statements. The Parkinsonian subjects were unable to produce statements in an angry or questioning form. These seemed to be features of early Parkinson's disease.