Several weeks ago, in early December 2013, health leaders from the Group of Eight (G8) met in London, pledging to cure or modify the course of dementia by 2025. This bold declaration is one that the Parkinson’s community is monitoring in light of the fact that about a quarter of people with PD are currently living with dementia. What Should You Know? Dementia describes a range of symptoms related to memory decline. While Alzheimer’s disease makes up the majority of cases of dementia, there are several kinds, including Parkinson’s disease-dementia (PD-D).