Neuropathology of Parkinson's disease dementia and dementia with Lewy bodies with reference to striatal pathology

Dementia is relatively common in Parkinson's Disease (PD). When dementia occurs in the setting of PD, it is referred to as Parkinson's disease dementia (PDD), which is distinguished from the clinical syndrome in which dementia precedes extrapyramidal features, dementia with Lewy bodies (DLB). In this report, the neuropathology of PDD and DLB is reviewed and preliminary findings are reported oil striatal pathology in 28 brains, including 7 PD, 7 PDD and 14 DLB. Sections of putamen immunostained for alpha-synuclein and investigated with image analysis show that striatal pathology is common and that both cortical and striatal alpha-synuclein pathology is greater in PDD and DLB than PD. Most cases of PDD and DLB have Alzheimer-type pathology, particularly amyloid plaques, which may act in all additive or synergistic manner with alpha-synuclein pathology. There are few pathologic differences between PDD and DLB, despite differences ill their clinical course. (C) 2007 Elsevier B.V. All rights reserved.