The effect of Parkinson's disease on language

To study the effect of idiopathic Parkinson's disease (PD) on language competence and performance, study participants were given an extensive battery of 15 linguistic communication tasks to assess both linguistic knowledge and the ability to use language. No evidence was obtained of impaired linguistic competence or performance in the non-demented PD patients or of impaired linguistic competence in PD patients with questionable mental status, who differed in performance from normal elders only in the Generative Naming of animals. Mildly demented PD patients differed from normal elders and nondemented PD patients on Confrontation Naming, Generative Naming, Definitions, Repetition, and Semantic Correction. The argument is advanced that the pattern of performance of mildly demented PD patients suggests impaired linguistic performance but spared linguistic competence. Of the tasks administered, Generative Naming was most sensitive to mental status.