SNCA and Lewy body dementia: The accumulation of α-synuclein in Lewy bodies (LBs) and Lewy neurites (LNs) across multiple brain regions from the brainstem to the neocortex117 is a defining feature of numerous synucleinopathies such as PD, dementia with Lewy body (DLB), and diffuse Lewy body disease118,119.