Usability of cerebrospinal fluid biomarkers in a tertiary memory clinic

Abstract

Aim: Assays for cerebrospinal fluid (CSF) levels of total tau, phospho-tau protein and beta-amyloid 1-42 have been available for some years. The aim of the study was to assess the usability of these biomarkers in a mixed population of tertiary dementia referral patients in a university-based memory clinic.

Methods: 147 consecutive patients with a lumbar puncture as a part of their clinical workup were studied. A retrospective diagnosis was established based on consensus criteria without the knowledge of the CSF results.

Results: When diagnosing Alzheimer's disease (AD) compared to other diagnoses, the sensitivity of a single abnormal value was between 33 and 66%. The specificity was high except when discriminating AD from amnestic mild cognitive impairment. Two or more abnormal markers further increased the specificity and decreased the sensitivity.

Conclusion: In a tertiary setting, abnormal CSF biomarker results may be of a diagnostic value - whereas normal results do not exclude neurodegenerative disease.