Pragmatic communication is impaired in Parkinson disease.

The purpose of this study was to determine whether severity of disease, cognitive function, age, gender, or amount of social interaction were associated with pragmatic dysfunction in Parkinson disease. No studies have previously been done to investigate variables that may be associated with pragmatic dysfunction in Parkinson disease. A case-control study was conducted with 17 Parkinson disease patients and 17 convenience controls. Each Parkinson disease patient and a control were interviewed, and their pragmatic skills were evaluated using a scale of pragmatic communication skills. Correlation analysis was used to determine what factors were associated with pragmatic dysfunction in the Parkinson disease patients. Cases scored lower on the pragmatic scale with a mean of 29.7 compared with 38.9 in the controls (p < .001) out of 40 possible points. The score on the scale of pragmatic communication skills had moderate to strong correlations with the MMSE (r = .81, p = .002), Unified Parkinson's Disease Rating Scale score (r = -.71, p = .002), and duration of disease (r = -.53, p = .03). These results show that Parkinson disease patients have impaired pragmatic function compared with controls on both verbal and nonverbal sections, and this impairment correlates with mental state, duration, and severity of disease.