Patient and Clinician Impressions of Cognitive Impairment in Parkinson's Disease.

We investigated patient and clinician impressions of cognitive impairment and whether they correlated with objective measures of cognitive impairment. Cognitive categorization, neuropsychological assessment scores, and Montreal Cognitive Assessment scores were documented at baseline, 3 years, and 7 years for 388 PD patients in the Parkinson's Progression Marker Initiative (PPMI). We found that both patient and clinician impressions of cognitive decline were significantly associated with gold-standard criteria for cognitive impairment to a similar degree. Both patient and clinician perspectives should be considered in determining cognitive status and should be followed up with diagnostic testing.