Neurology 2020 09 7;95(9):e1134-e1143. Epub 2020 Jul 7.
From the German Center for Neurodegenerative Diseases (S.W., L.K., J.G., A.P., I.F., S.R., M.T., A. Spottke, A.R., B.K., K.F., A. Schneider, M.H., F.B., D.M., F.J., M.W.); Department of Neurodegenerative Diseases and Geriatric Psychiatry (S.W., L.K., J.G., A.P., I.F., A.R., B.K., K.F., A. Schneider, M.T.H., F.B., M.W.), University of Bonn; German Center for Neurodegenerative Diseases (E.J.S., J.P., O.P., F.M., M.F.C.); Department of Psychiatry and Psychotherapy (E.J.S., C.F., J.P.), Charité-Universitätsmedizin Berlin; German Center for Neurodegenerative Diseases (I.K., S.T.); Department of Psychosomatic Medicine (I.K., S.T.), Rostock University Medical Center; German Center for Neurodegenerative Diseases (K.B.); Institute for Stroke and Dementia Research (K.B., D.J.), University Hospital, LMU Munich; German Center for Neurodegenerative Diseases (C.L., M.B.); Section for Dementia Research (C.L., M.B.), Hertie Institute for Clinical Brain Research and Department of Psychiatry and Psychotherapy, University of Tübingen; Charité-Universitätsmedizin Berlin (O.P., F.M., M.F.C.), corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin; (O.P., F.M., M.F.C.), Berlin Institute of Health, Institute of Psychiatry and Psychotherapy; German Center for Neurodegenerative Diseases (J.W., C.B.); Department of Psychiatry and Psychotherapy (J.W., C.B.), University Medical Center Goettingen, University of Goettingen; German Center for Neurodegenerative Diseases (E.D., C.M.); Institute of Cognitive Neurology and Dementia Research (E.D., C.M., W.G.) and Department of Psychiatry and Psychotherapy (C.M.), Otto-von-Guericke University, Magdeburg; Department of Neurology (A. Spottke), University Hospital Bonn; and Division of Neurogenetics and Molecular Psychiatry (A.R.) and Department of Psychiatry (M.T., D.M., F.J.), Medical Faculty University of Cologne, Germany.
Objective: To determine the nature and extent of minor neuropsychological deficits in patients with subjective cognitive decline (SCD) and their association with CSF biomarkers of Alzheimer disease (AD).
Method: We analyzed data from n = 449 cognitively normal participants (n = 209 healthy controls, n = 240 patients with SCD) from an interim data release of the German Center for Neurodegenerative Diseases Longitudinal Cognitive Impairment and Dementia Study (DELCODE). An extensive neuropsychological test battery was applied at baseline for which we established a latent, 5 cognitive domain factor structure comprising learning and memory, executive functions, language abilities, working memory, and visuospatial functions. We compared groups in terms of global and domain-specific performance and correlated performance with different CSF markers of AD pathology.
Results: We observed worse performance (Cohen d = ≈0.25-0.5, adjusted for age, sex differences with analysis of covariance) in global performance, memory, executive functions, and language abilities for the SCD group compared to healthy controls. In addition, worse performance in these domains was moderately ( = ≈0.3) associated with lower CSF β-amyloid and CSF β-amyloid/phosphorylated tau181 in the whole sample and specifically in the SCD subgroup.
Conclusions: Within the spectrum of clinically unimpaired (i.e., before mild cognitive impairment) cognitive performance, SCD is associated with minor deficits in memory, executive function, and language abilities. The association of these subtle cognitive deficits with AD CSF biomarkers speaks to their validity and potential use for the early detection of underlying preclinical AD.