Grant: Project Grant

Dementia is very common in Parkinson's, with up to 80% of patients developing dementia within the first ten years of disease. Despite its prevalence, the causes of dementia remain largely unknown and as a result, no effective treatments are available. The evolution and severity of cognitive dysfunction observed in Parkinson's disease varies a lot from one patient to the next. This suggests that different patients may have different causes for their dementia. Consistent with this, recent research has shown that some patients with Parkinson's disease who develop dementia also have evidence of other brain diseases known to cause dementia. In particular, Alzheimer's disease and vascular disease, which both cause dementia, are thought to co-exist with Parkinson's disease in some patients. However, exactly how much they contribute to dementia - above and beyond having Parkinson's disease - is unknown. The goals of this project are therefore to: 1.Determine if Alzheimer's disease causes dementia in individuals with Parkinson's disease. 2.Determine if vascular disease causes dementia in individuals with Parkinson's disease. 3.Identify ways to predict which individuals with Parkinson's disease will develop dementia due to one of these causes. To achieve these goals we will follow 275 Parkinson's patients over time. Patients will undergo detailed assessments, including cognitive testing, blood tests and MRI scans. Major recent scientific breakthroughs have led to new treatments for some forms of dementia, including Alzheimer's disease, but we don't know yet if these could be useful in Parkinson's disease. The results of this research could therefore drastically change the way we treat dementia in individuals with Parkinson's disease by proving that potentially modifiable brain diseases, separate from Parkinson's disease, also play a significant role in causing dementia in Parkinson's disease.