Cerebrospinal fluid biomarkers for cognitive disorders. An introductory overview

The core (established) cerebrospinal fluid biomarkers of Alzheimer’s disease (AD), namely amyloid-beta peptide, total tau protein and phospho-tau protein, have become a part of the diagnostic workup of patients with cognitive disorders in many specialized centers, especially for ambiguous cases. Combined, these biomarkers can identify the presence or absence of an AD biochemical process with sensitivities and specificities approaching or exceeding 90% in both dementia and pre-dementia stages of AD. Thus, they have been incorporated in various sets of research or clinical diagnostic criteria and recommendations. Results that are atypical, incompatible with AD, or inconclusive may occur, necessitating the use of other cerebrospinal fluid or imaging biomarkers.