Grant: Project Grant

Parkinson's disease (PD) is primarily recognized for its motor symptoms. However, deficits in cognition such as learning, memory and problem solving are noted in the early stages of PD. In some patients, these can evolve rapidly, and eventually resulting in dementia. The ability to identify patients who are predisposed to develop dementia at early stages of PD can allow for better management strategy and early intervention, and help improve quality of life. However, the current clinical tools used to detect cognitive deficits are time-consuming, and often available to a minority of PD patients. Furthermore, diagnosis often occurs too late when these deficits are well established. A new approach to detect dementia risk earlier involves identifying behavioral or personality changes in later life as potential early indicators of brain dysfunction that can lead to dementia. A neurobehavioral syndrome called Mild Behavioral Impairment (MBI), identifies later life onset of neuropsychiatric symptoms (NPS- i.e. changes in behavior or personality) as a high-risk group for developing dementia. For some, NPS may be the earliest manifestation of dementia, and can be first noticed by family members or caregivers using the MBI checklist (MBI-C). Outside the context of PD, previous studies have established a connection between high MBI-C scores at baseline and later occurrence of dementia. However it is not known whether MBI can also predict cognitive decline in PD. We will recruit patients with PD, perform cognitive and neuropsychiatric testing, as well as brain imaging at baseline, and again two and a half years later. We will evaluate how the MBI-C scores relate to cognitive decline and potential conversion to dementia in PD, and determine its relationship with brain anatomical and functional changes in PD. If successful, this study will demonstrate that the MBI-C is a sensitive, easy to apply and clinically relevant tool for the early prediction of cognitive decline in PD.