Neuropsychological signs of the neurodegenerative process in Alzheimer’s disease at the stage of mild cognitive impairment

Abstract

Currently, a huge number of works by domestic and foreign authors are devoted to the study of the neuropsychological heterogeneity of Alzheimer’s disease (AD) at the stage of mild cognitive impairment (MCI). The purpose of our study was to study the neuropsychological characteristics of AD at the stage of MCI depending on the timing of manifestation. The study involved 173 patients with asthma at the stage of MCI, of which 65 patients had early onset and 108 patients had late onset. All study participants underwent the Montreal Cognitive Assessment (MoCA), the Free Recall Test with selective cues and immediate recall (FCSRT-IR), the route-following test (drawing paths): part A and B; categorical and phonemic verbal fluency, digit recall (DST). The average age of patients with early onset of asthma was 65.1±0.3 years, with late onset — 78.6±0.5 years. According to the results of the study, it was found that patients with a late form of asthma coped with MoCA worse than a patient with an early form (p=0.043). Patients with late onset AD produced fewer words independently in the FCSRT-IR test compared to patients with early onset (p<0.001). Analysis of DST test performance in forward (p=0.41) and reverse order (p=0.197) did not show significant differences. We found that patients with early AD made more errors (p=0.000) and took longer to complete the route-following test, both parts A and B. There was no significant difference when assessing categorical verbal fluency (p=0.67). At the same time, patients with early onset AD named fewer words when assessing phonemic verbal fluency (p=0.000). The results of our study indicate the need for comprehensive, extensive neuropsychological testing in patients with suspected AD.