The response of the apparent receptive speech disorder of Parkinson's disease to speech therapy.

Eleven patients with Parkinson's disease were tested for prosodic abnormality, on three tests of speech production (of angry, questioning, and neutral statement forms), and four tests of appreciation of the prosodic features of speech and facial expression. The tests were repeated after a control period of two weeks without speech therapy and were not substantially different. After two weeks of intensive domiciliary prosodic therapy, the prosodic abnormality score was improved, as were three of the four tests of recognition of the prosodic features of speech and facial expression, and two of the three tests of production (of angry and questioning forms). The apparent receptive disorder of speech in Parkinson's disease can thus respond to therapy. Possible mechanisms of improvement are briefly discussed.