Parkinson's Disease Dementia, Dementia with Lewy Bodies, and Other Synucleinopathies
Summary
This chapter deals with dementia in Parkinson's disease (PDD), dementia with Lewy bodies (DLB), and cognitive impairment/dementia in multiple system atrophy (MSA). In Parkinson's disease (PD), PDD, and DLB, aggregates of α-synuclein in the cytoplasm of different populations of neurons are present in the form of Lewy bodies (LB) and dystrophic Lewy neurites that constitute the neuropathological hallmarks of these disorders. Dementia occurs in up to one-third of all PD patients. It is characterized by deficits in attention and executive and visuospatial functions, by memory impairment, and by prominent behavioral symptoms. DLB is a common form of dementia representing 15-20% of cases of dementia in old age and is the second most prevalent cause of neurodegenerative dementia after Alzheimer's disease. Cognitive deterioration is a key feature for DLB diagnosis. MSA is characterized by varying severity of parkinsonian symptoms, cerebellar ataxia, autonomic and urogenital dysfunction, and corticospinal signs.
