Diagnosing Alzheimer Disease: Which Dementia Screening Tool to Use in Elderly Puerto Ricans with Mild Cognitive Impairment and Early Alzheimer Disease?

Abstract

BackgroundMost of the time, Alzheimer Disease (AD)’s diagnosis is not made at its earliest periods and prodromal stages, for instance at Mild Cognitive Impairment (MCI) and Early Alzheimer Disease (E‐AD) stage. Commonly, AD’s diagnosis is made when significant impairment interferes with the habitual daily activities (1). Our pilot study, serves to demonstrate a correlation between the screening tools, including the Mini‐mental Status Exam (MMSE), Montreal Cognitive Assessment (MoCA) and Clinical Dementia Rating Scale (CDR), and the biological biomarkers in the cerebral spinal fluid (CSF) (Amyloid Beta 1‐42 (Aβ42 pg/mL), Tau proteins (tTau (pg/mL) and tTau/Aβ42 ratio in Puerto Ricans > 55 years old with MCI and E‐AD. To our knowledge, this is the first study trying to create a correlation between memory tests scores and underlying AD pathology to improve early detection in elderly Puerto Ricans.MethodThirty participants were evaluated including, demographics, clinical characteristics, memory scales and CSF biomarkers. CSF biomarkers (Aβ42, tTau protein, and tTau/Aβ42 ratio) were determined using the Meso Scale Discovery Platform (MSD). Associations between memory scales (MOCA, MMSE, CDR) and CSF markers were performed using Spearman’s rho correlation.ResultOur study revealed statistical association in favor of a direct relationship between MMSE and tTau/Aβ42 ratio in CSF (p= .022, 95.00% CI = [‐.69, ‐.07] (Figure 1). We found a trend towards significance with an inverse relationship with MMSE and Aβ42 (p=.069) (Figure 2) and a direct relationship with MMSE and tTau (p= .098) (Figure 3). Besides, MoCA and tTau/Aβ42 ratio had a statistically significant direct relationship (p = 0.035) (Figure 4). There was no significant statistical association between CDR test with CSF biomarkers in elderly Puerto Ricans.ConclusionMMSE was the dementia screening test consistently identifying a statistically significant or a‐trend‐towards a significant association with the CSF Alzheimer Disease’ s biomarkers (Aβ42, tTau protein, and tTau/Aβ42 ratio) in elderly Puerto Ricans with MCI and E‐AD. Clinically, > 55 y/o Puerto Rican patients with MCI and E‐AD should be screened with MMSE for a higher likelihood of earlier detection and, thus, initiation of disease‐modifying treatment.