Visual hallucinations associated with Parkinson disease

To determine factors that are predictive for the development of hallucinations associated with Parkinson disease (PD).

Hallucinations are a common difficulty for patients with established PD, and hallucinations and psychosis may be the most common causes for nursing home placement. The characteristics of the hallucinations associated with PD differ from the hallucinations associated with schizophrenia or cocaine abuse. Multiple factors have been suggested as causal.

A total of 214 consecutive patients were interviewed during routine visits to the Parkinson's Disease Clinics in Columbus, Ohio, and Miami, Fla, using a hallucination questionnaire, Folstein Mini-Mental State Examination, and an attempt to correlate age, duration of disease, medication, and psychological or sleep disorders with the hallucinations.

Hallucinations were almost exclusively visual and were present in 55 of the 214 patients. Dementia, age, duration of disease, history of depression, or history of sleep disorder were strongly associated with the hallucinations.

While reduction in levodopa and anticholinergic medication doses is appropriate in the management of hallucinations, the factors that predispose patients to hallucinations include dementia and advancing age. The phenomena of visual hallucinations associated with PD, while not fully explained, are unique enough to be of interest to all neurologists and neuroscientists.