Diagnosing Alzheimer's disease: Which dementia screening test to use in elderly Puerto Ricans with mild cognitive impairment and early Alzheimer's disease?

Abstract

Abstract Typically, Alzheimer's disease (AD) diagnosis is not made at its earliest period, for instance, at mild cognitive impairment (MCI) and early AD (E‐AD). Our study aims to demonstrate a correlation between the screening tools, including the Mini‐Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Clinical Dementia Rating (CDR), and the biological biomarkers in the cerebrospinal fluid (CSF) amyloid beta 1‐42 (Aβ42), phosphorylated tau (p‐tau) proteins and total tau (t‐tau)/Aβ42 ratio in Puerto Ricans > 55 years old with MCI and E‐AD. We evaluated 30 participants, including demographics, memory scales, and CSF biomarkers. Twenty‐eight CSF biomarkers (Aβ42, p‐tau protein, and t‐tau/Aβ42 ratio) were analyzed using the Meso Scale Discovery Platform (MSD). Associations between memory scales (MoCA, MMSE, CDR) and CSF markers were performed using Spearman rho correlation. Our study revealed a statistical association favoring a direct relationship between MMSE and MoCA with t‐tau/Aβ42 ratio in CSF (P = 0.022, P = 0.035, respectively). We found a trend toward significance with an inverse relationship with MMSE and Aβ42 (P = 0.069) and a direct relationship with MMSE and p‐tau (P = 0.098). MMSE and MoCA screening tests were identified with a statistically significant association with the CSF biomarkers, specifically t‐tau/Aβ42 ratio, in elderly Puerto Ricans with MCI and E‐AD. Puerto Ricans > 55 years old with MCI and E‐AD could be screened confidently with MMSE and MoCA for a higher likelihood of earlier detection and, thus, initiation of disease‐modifying treatment and prompt non‐pharmacological interventions.

Keywords

• cerebrospinal fluid
• Clinical Dementia Rating
• early Alzheimer's disease
• mild cognitive impairment
• Mini‐Mental State Examination
• Montreal Cognitive Assessment