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.