Dementia in Parkinson's disease: a post-mortem study in a population of brain donors

OBJECTIVE: To identify factors associated with dementia in a cohort of Parkinson's disease (PD) brain donors and determine whether its presence may influence the clinical phenotype of the disease. METHODS: We included 67 consecutive patients with a clinical and pathological diagnosis of PD, who while alive, consented to donate their brains to the University of Miami Brain Endowment Bank(TM). Dementia and psychiatric complications of PD were diagnosed according to established criteria. Case histories were abstracted and reviewed and comparisons between PD patients with (PD-D, n = 34) and without (PD, n = 33) dementia were made. RESULTS: Age at death, age at disease onset and disease duration did not differ significantly between PD-D and PD patients. Other symptoms were similar in both groups. Visual hallucinations and bilateral symptoms at diagnosis were significantly higher in PD-D patients. No association between dementia and overall survival duration was found. Although the frequency of depression and psychosis was higher in the PD patients with dementia no statistical significance was reached. The overall lifetime prevalence of dementia in our group was 50.7%. CONCLUSIONS: Visual hallucinations and bilateral symptoms were associated with dementia in our cohort of PD brain donors. No association between dementia and survival duration was found. Understanding the influence of dementia on the clinical phenotype of the disease and predicting its development is essential for the successful management of PD.