Tau protein, beta-amyloid₁₋₄₂ and clusterin CSF levels in the differential diagnosis of Parkinsonian syndrome with dementia.

BACKGROUND: Parkinson's disease (PD), PD with dementia (PDD) and Lewy body dementia (DLB) are synucleinopathies. PDD and DLB are sometimes considered a transition between PD and Alzheimer dementia (AD). Finding in vivo markers or their combination could help in the differential diagnosis of these neurodegenerative (ND) diseases.

OBJECTIVE: The aim of this study was to assess cerebrospinal fluid (CSF) levels of tau protein, betaamyloid1-42 and clusterin and to compare these levels among patients with probable PD, PDD, DLB and AD.

METHODS: CSF levels of ND markers were assessed in 96 patients (27 patients with PD, 14 with PDD, 14 with DLB, 17 with AD and 24 subjects as a control group).

RESULTS: In all of the groups of patients, beta-amyloid1-42 levels were decreasing in the order PD>PDD>DLB>AD, whereas tau protein and the tau protein/beta-amyloid1-42 index were increasing in the same order (PD
CONCLUSION: The results of the present study support the role of clusterin in PD pathogenesis. The decreasing CSF beta-amyloid1-42 levels in the order PDD, DLB and AD may relate to the increasing presence of AD pathology in these disorders.