Supplementary Material for: The Memory Alteration Test is correlated with clinical, cerebrospinal fluid, and brain imaging markers of Alzheimer disease in Lima, Peru

Introduction. As disease modifying therapies become available, early detection of Alzheimer’s disease (AD) becomes increasingly important. However, biomarkers in LMICs are rare and costly. Thus, we evaluated an AD-focused BCT, the Memory Alteration Test (M@T), to detect biomarker-proven AD and quantify its correlation with neurodegeneration and CSF AD biomarkers in a cohort of participants from Lima, Peru. Methods. This is a secondary analysis of a cohort of 185 participants: 63 controls, 53 with amnestic MCI (aMCI), and 69 with dementia due to AD. Participants underwent testing with M@T and a gold standard neuropsychological battery. We measured T-tau, p-tau and β-amyloid in CSF, and evaluated neurodegeneration via medial temporal atrophy score in MRI. We used Receiver-Operator Curves to determine the discriminative capacity of the total M@T score and its subdomains. We used the Pearson coefficient to correlate M@T score and CSF biomarkers. Results. The M@T had an AUC of 0.994 to discriminate between controls and cognitively impaired (aMCI or AD) patients, and an AUC of 0.98 to differentiate between aMCI and AD patients. Free-recall and cued recall had the highest AUCs of all subdomains. Total score was strongly correlated with t-tau (-0.77) and p-tau (-0.72), and moderately correlated with β-amyloid (0.66). The AUC for discrimination of neurodegeneration was 0.87. Discussion/Conclusion. The M@T had excellent discrimination of aMCI and dementia due to AD. It was strongly correlated with CSF biomarkers and had good discrimination of neurodegeneration. In LMICs, it may represent a cost-effective screening tool for aMCI and dementia caused by AD.