Clinical evaluation of Parkinson?s disease dementia: association with aging and visual hallucination

OBJECTIVES: In order to explore factors associated with the development of dementia in Parkinson's disease (PD) and Dementia with Lewy bodies (DLB), we systematically investigated the clinical evaluation of PD and DLB patients hospitalized in the Department of Neurology at Tottori University Hospital, Japan. RESULTS: There were 208 patients diagnosed as having PD and 39 patients diagnosed with DLB in this study. Of the patients with PD, 67 (32%) developed dementia and only five PD+ patients were considered to have cognitive impairment attributable to Alzheimer's disease (AD) or vascular dementia (VaD). Fifty-four (81%) PDD patients had visual hallucinations (VH) with or without cognitive fluctuation. The onset age of parkinsonian motor symptoms of patients with PD dementia (PDD) did not differ from that of PD patients without dementia. There was a significant inverse correlation between the onset age of motor symptoms in PD and the onset of their dementia in PDD. Seventy-five (36%) patients with PD had experienced VH and most of the PDD patients had experienced VH within 1 year before or after diagnosis of PDD. CONCLUSIONS: These results indicate that aging and VH are important factors associated with dementia in PD.