Investigating the relationships between cognitive impairment score, cerebrospinal fluid measures and dementia diagnosis

Abstract Background Cerebrospinal fluid (CSF) dementia markers are sensitive to cognitive decline, particularly memory (Hosseini et al, 2023). Methods We performed preliminary analyses on a neurodegenerative and non‐neurodegenerative patient dataset, collected as part of the CogNID study (IRAS reference: 250525, clinical trial reference: NCT03861884). We explore two questions, the first of which regards whether cognitive profile measured by the Addenbrooke’s cognitive examination (ACE‐R III) can predict diagnosis category, clustered into three groups: 1) Alzheimer’s Disease (AD; N=50), 2) non‐AD dementia conditions (e.g., frontotemporal dementia, Vascular Cognitive Impairment, Parkinson’s disease; N=46), and 3) a mixed, non‐dementia group serving as “control” (e.g., subjective cognitive impairment, post‐Covid‐19 brain fog; N=64). The second question asked whether, for a smaller subset of our participants with CSF dementia measures, there is any correlation between CSF dementia biomarkers and cognitive impairment. We explored these using regression analysis and Pearson’s correlation tests. Results For our total sample with recorded ACE‐R III scores (N=160, M age =59.3, SD age =6.4), participants’ memory (t=‐2.31, p=.02) and language (t=2.16, p =.03) scores predicted their diagnosis category. Post‐hoc split‐data regression analyses revealed only a significantly lower memory score for the AD group compared to control group (t=‐2.482, p=.015). None of the other comparisons showed a significant difference after multiple‐comparisons corrections. For our second question, we selected a subsample of our data with recorded CSF measures (N=56). We assessed the CSF measures of total 181‐Tau, phospho‐Tau and Amyloidß 1‐42 in these participants in relation to their memory, attention and visuospatial, obtained from the ACE‐R III scores. We found a significant negative correlation between 181‐phospho‐Tau (but not total Tau) and memory scores (r=‐.37, p=.005), indicating that higher 181‐phospho‐Tau measures were significantly associated with impaired memory performance. Conclusions The preliminary analysis is limited by the high diversity of our neurodegenerative non‐AD group. A more detailed exploration of memory is crucial during diagnostic assessments of suspected AD. Disclosure and funding : AAH is funded by the UK Medical Research Council (MR/T005580/1). Reference : https://alz‐journals.onlinelibrary.wiley.com/doi/full/10.1002/alz.054530