Individuals with multiple system atrophy with parkinsonism, dementia with Lewy bodies, and Parkinson disease dementia have increased mortality compared with the general population, according to a recent study. This population-based study used the Rochester Epidemiology Project medical records–linkage system to identify all residents in Olmsted County, MN, who received a diagnosis of parkinsonism from 1991 through 2010. Researchers found:

• Of the 461 patients with synucleinopathies, 279 (60.5%) were men, and of the 452 referent participants, 272 (60.2%) were men.
• From 1991 through 2010, the total number of individuals received a diagnosis of a synucleinopathy (309 [67%] of Parkinson disease, 81 [17.6%] of dementia with Lewy bodies, 55 [11.9%] of Parkinson disease dementia, and 16 [3.5%] of multiple system atrophy with parkinsonism).
• Patients with multiple system atrophy with parkinsonism had the highest risk of death compared with referent participants.
• Neurodegenerative disease was the most frequent cause of death listed on the death certificate for patients, and cardiovascular disease was the most frequent cause of death among referent participants.