[The experience of diagnosing Alzheimer's disease based on the study of cerebrospinal fluid biomarkers].

Abstract

Objective: To evaluate the frequency of Alzheimer's disease (AD) confirmed by cerebrospinal fluid (CSF) biomarkers in a cohort of patients with classical (amnesic) and atypical phenotypes of this disease.

Material and methods: The study included 63 patients (24 men and 39 women; median age 65 years [60; 71]). All patients were divided into 3 groups according to the phenotype: a classic amnesic phenotype (n=32), frequent non-amnesic phenotypes (n=21) and rare non-amnesic phenotypes (n=10). All patients underwent lumbar puncture followed by the CSF biomarkers evaluation (beta-amyloid 1-42 (Aβ1-42) and phosphorylated tau protein 181 (p-tau181)) to confirm the AD pathology. The clinical characteristics of each subgroup were studied.

Results: A decreased level of CSF Aβ1-42 in combination with an increased level of p-tau181 was found in 36 patients (57.1%). A change in at least one biomarker was detected in 54 patients (85.7%). The highest frequency of the Alzheimer's type pathology was found in the group with predominant amnestic phenotype (87.5%), as well as in the subgroups with logopenic variant of primary progressive aphasia (lvPPA) (100%) and with posterior cortical atrophy (PCA) (100%). In the group with rare phenotypes, the frequency of AD CSF changes characteristic of AD was 50% for patients with predominant behavioral disorders and 66.7% for corticobasal syndrome.

Conclusion: The high frequency of AD CSF biomarkers in both the classical (amnesic) and atypical phenotypes is shown. This indicates the need to expand the use of AD CSF biomarkers for a more reliable assessment of the prevalence of AD In Russia.