To assess whether ATP13A2 levels in Lewy body disease are modified by Alzheimer-type β-amyloid deposition, we evaluated cases of pure PD and pure dementia with Lewy bodies (DLB) for changes in ATP13A2, α-synuclein and β-amyloid protein levels in cortical regions with and without Lewy bodies. Here, ATP13A2 is linked to Lewy body dementia.