CSF biomarkers for mild cognitive impairment and early Alzheimerʹs disease

A correct clinical diagnosis, early in the course of Alzheimerʹs disease (AD), is of importance given the currently available symptomatic treatment with acetylcholine esterase inhibitors. The development of disease-modifying drugs like β-sheet breakers or γ- and β-secretase inhibitors, emphasizes the need of improved diagnostic accuracy, especially in patients with mild cognitive impairment (MCI) that have incipient AD. Therefore, diagnostic markers in the cerebrospinal fluid (CSF) have become a rapidly growing research field. Three cerebrospinal fluid biomarkers (the 42 amino acid form of β-amyloid (Aβ), total tau, and phospho tau) have been evaluated in numerous scientific papers. These CSF markers have high sensitivity to differentiate early and incipient AD from normal aging, depression, alcohol dementia and Parkinsonʹs disease, but lower specificity against other dementias, such as frontotemporal and Lewy body dementia. If these biomarkers are used in combination with a careful medical history, clinical examination, standard laboratory tests and imaging techniques of the brain, the diagnostic accuracy may be appropriate for the clinical evaluation of MCI cases.