Cognitive Changes in Parkinson’s Disease Patients with Visual Hallucinations

OBJECTIVE: To evaluate the decline in specific neuropsychological functions in nondemented Parkinson's disease (PD) patients with a history of visual hallucinations (VH). METHODS: Twenty PD patients with VH, 20 PD patients without VH and 18 normal controls were followed up over a 1-year period and assessed for cognitive decline. RESULTS: Forty-five percent of nondemented hallucinating PD patients developed dementia during the 1-year period between baseline and follow-up evaluations. Of the nondemented hallucinating PD patients nearly 70% showed impairment in multiple cognitive domains. The progressive decline in hallucinating PD patients affected mainly visual memory for faces and visuoperceptive-visuospatial functions. CONCLUSION: Our results support a fast impairment of complex visual functions in hallucinating PD patients, but also a progressive decline in multiple cognitive domains, which have been identified as a risk of developing dementia in PD.