Cerebrospinal fluid biochemical markers in early detection and in differential diagnosis of dementia disorders in routine clinical practice

Measurement of total tau and amyloid beta((1-42)) (Ab42) in cerebrospinal fluid (CSF) improves diagnostic accuracy of Alzheimer's disease (AD). We examined a consecutive patient sample referred to our center for diagnostic assessment of cognitive decline. CSF tau and Abeta42 were assayed each week as routine neurochemical analyses. There were 119 patients investigated. These included 61 with probable AD (35 mild AD, 26 severe AD), 24 with mild cognitive impairment (MCI), 14 with vascular dementia, 11 with Lewy body dementia, and 9 with fronto-temporal dementia. Mild AD showed significantly lower CSF Abeta42 levels and significantly higher CSF tau levels than the other diagnostic groups; 79% of MCI patients had pathological values for both biomarkers. We confirm that these biomarkers have a role in the clinical work-up of patients with cognitive deficits.