Increased Total Tau But Not Amyloid-beta(42) in Cerebrospinal Fluid Correlates with Short-Term Memory Impairment in Alzheimer's Disease

Given the need for tools for early and accurate diagnosis, prediction of disease progression, and monitoring efficacy of therapeutic agents for AD, the study of cerebrospinal fluid (CSF) biomarkers has become a rapidly growing field of research. Several studies have reported conflicting data regarding the relationships between CSF biomarkers and dementia severity. In this study, we have focused on the identification of CSF biomarkers and their correlations with the impairment of different cognitive domains measured using the Cognitive Abilities Screening Instrument (CASI). Patients with AD (n = 28), non-AD dementia (n = 16), other neurological disorders (OND, n = 14), and healthy controls (HC, n = 21) were enrolled. Our results revealed significantly higher CSF total tau (t-tau) and lower amyloid-beta(42) levels in AD patients compared with those in HC and OND groups. Moreover, our data show that CSF t-tau levels, but not A beta(42) levels, have an inverse correlation with the score of short-term memory in CASI for patients with AD (Spearman: r = -0.444; p = 0.018). This data might indicate that the higher CSF t-tau level is associated with more NFT pathology and more severe impairment of short-term memory in AD patients.