Dementia Predictors in Parkinson Disease: A Validation Study.

In a prospective study, we recently discovered 8 clinical predictors of dementia in Parkinson's disease. Here, we validate these dementia predictors using two additional prospective cohorts (n = 134). After a 3.6-year follow-up, 35/134 developed dementia (7.2% per year). When confirming individual variables, 5/8 were significantly associated with dementia in the validation cohort. These included age, male sex, baseline RBD, orthostatic hypotension, and MCI. Bilateral onset, hallucinations and falls/freezing did not significantly predict dementia; however, point estimates of OR were all >1. In all cohorts, the strongest determinant for dementia development was the co-existence of RBD, MCI and orthostatic hypotension at baseline.