Beta-amlyoid 1-42 and tau-protein in cerebrospinal fluid of patients with Parkinson's disease dementia

Measurement of tau-protein and beta-amyloid(1-42) (A beta 42) in cerebrospinal fluid (CSF) has gained increasing acceptance in the differential diagnosis of Alzheimer's disease. We investigated CSF tau-protein and A beta 42 concentrations in 73 patients with advanced idiopathic Parkinson's disease with dementia (PDD) and 23 patients with idiopathic Parkinson's disease without dementia (PD) and in a comparison group of 41 non-demented neurological patients (CG) using commercially available enzyme-linked-immunoabsorbant- assay ( ELISA). tau-Protein levels were statistically significantly higher and A beta 42 lower in the PDD patients compared to PD patients and the CG. This observation was most marked ( p < 0.05) in a subgroup of patients with PDD carrying the apolipoprotein genotype epsilon 3/epsilon 3. The distribution of the apolipoprotein genotypes in PDD and PD patients was similar to that of the CG. Although a significant difference in tau-protein values was observed between PDD and CG, no diagnostic cut-off value was established. These findings suggest that such protein CSF changes may help to support the clinical diagnosis of cognitive decline in PD and that there may be apolipoprotein-E-isoform- specific differences in CSF protein regulation in advanced PDD. Copyright (C) 2006 S. Karger AG, Basel.