Striatal β-amyloid deposition in Parkinson disease with Dementia

Abstract

Dementia is common in Parkinson disease (PD), although its anatomic and pathologic substrates remain undefined. Recently, striatal abnormalities in Lewy body diseases have been described, but their clinical relevance is not clear. Thirty PD cases from the United Kingdom Parkinsoǹs Disease Society Tissue Bank were grouped as demented (PDD; n = 16) and nondemented (PD; n = 14) based on a review of clinical records. The extent of a-synuclein, tau, and amyloid A peptide (βA) deposition in the caudate nucleus, putamen, and nucleus accumbens was assessed. All cases showed severe dopaminergic striatal terminal denervation based on tyrosine hydroxylase immunohistochemistry. a-synuclein and tau deposition in the striatum were rare in both groups, but the AA burden was significantly greater in the striatum of PD cases with dementia than present in the nondemented PD group. Striatal βA deposition was type-independent of Alzheimer disease changes in the cortex and was minimal in nondemented PD cases. We conclude thatβA deposition in the striatum strongly correlates with dementia in PD. Copyright © 2008 by the American Association of Neuropathologists, Inc.