THE DEVELOPMENT OF HALLUCINATIONS IN PARKINSON'S DISEASE

Movement Disorders [2011] 26 (12) : 2196-2000 (Goetz CG, Stebbins GT, Ouyang B.) Complete abstract

Although visual hallucinations on their own are considered classic Parkinson's Disease symptoms, non-visual hallucinations also develop over time, and the combination of visual with non-visual hallucinations dominates in late Parkinson's Disease. The objective of this study was to assess the development and evolution of visual and non-visual hallucinations in people with Parkinson's Disease over 10 years. Over 10 years, visual hallucinations were still found to be more frequent than other forms of hallucinations.

Isolated visual hallucinations dominate the early years of Parkinson's Disease, but visual plus non-visual hallucinations accounted for progressively higher proportions of people with Parkinson's Disease. Hallucination severity was highly associated with somebody currently having visual plus non-visual hallucinations.  After 6 months with Parkinson's Disease, virtually nobody had hallucinations. However, after 4 years, over a quarter (26%) of people with Parkinson's Disease had hallucinations. After 6 years, nearly half (47%) of people with Parkinson's Disease had hallucinations. After 10 years with Parkinson's Disease, 60% of people had hallucinations. Once somebody had both visual and non-visual hallucinations, the risk of continuing to have them was high.