The protective impact of education on brain structure and function in Alzheimer’s disease

Abstract

Background The Cognitive Reserve (CR) theory posits that brains with higher reserve can cope with more cerebral damage to minimize clinical manifestations. The aim of this study was to examine the effect of education (CR proxy) on brain structure and function in Alzheimer’s disease (AD) and amnestic mild cognitive impairment (aMCI) patients and in cognitively healthy elderly (HC) individuals. Methods Fifty-seven AD patients, 57 aMCI patients and 48 HCs were included to investigate the relationships between education years and gray matter volume (GMV), regional homogeneity (ReHo) and functional connectivity (FC) in brain regions to show associations with both structure and function. Taking the severity of the disease into account, we further assessed the relationships in AD stratified analyses. Results In AD group, the GMV of the dorsal anterior cingulate cortex (dACC) and ReHo in the left inferior temporal cortex (ITC) were inversely associated with education years, after adjustment for age, sex, Mini-Mental State Examination (MMSE), and total intracranial volume or head motion parameters. Seed-based FC analyses revealed that education years were negatively correlated with the FC between the left anterior ITC and left mid frontal cortex as well as right superior frontal cortex and right angular gyrus. Stratified analyses results indicated that this negative relation between education and GMV, ReHo, FC was mainly present in mild AD, which was attenuated in moderate AD and aMCI groups. Conclusions Our results support the CR theory, and suggest that CR may be protective against AD related brain pathology at the early stage of clinical dementia. These findings could provide the locus of CR-related functional brain mechanisms and a specific time-window for therapeutic interventions to help AD patients to cope better with the brain pathological damage by increasing CR.

Dissecting Alzheimer’s Disease Risk in Asian American Elders: A Classification and Regression Tree Approach

“…The findings illustrate a consistent protective effect of education against the risk of developing AD, with a dose-dependent relationship prevailing across genders and age groups [16,17]. Similarly, in a few studies, it was underscored that education may play a pivotal role in bolstering brain reserve and fortifying cognitive coping strategies, not just in healthy individuals but also in patients diagnosed with AD [18][19][20]. Notably, Asian Americans exhibit higher education levels, potentially attributed to immigration trends and the "model minority" stereotype, reinforcing the importance of studying this group in the context of AD [21].…”

“…In another study, a complex case of progressive supranuclear palsy (PSP) accompanied by depression and anxiety, was presented. The patient showed extrapyramidal symptoms and major depression, leading to impaired movement [ 19 ]. Antidepressant therapy was initiated, resulting in a reduction of depressive symptoms and somatic complaints.…”

Cognitive decline and alcohol consumption in the aging population—A longitudinal analysis of the Survey of Health, Ageing and Retirement in Europe

“…Previous explanations for this association between reduced risk for cognitive decline or dementia and a higher degree of educational obtainment hypothesised that this cognitive exertion in early-and mid-life stages might result in an increased cognitive reserve in older age. A further explanation may be that individuals with higher levels of educational obtainment may engage in mentally stimulatory activities more frequently, especially in later life stages, contributing to the preservation of cognitive function and, thus, impeding the onset of cognitive decline [41][42][43].…”

Correlations between cognitive reserve, gray matter, and cerebrospinal fluid volume in healthy elders and mild cognitive impairment patients

“…What is more, CR has also been shown to modulate the cortical architecture, white matter macromolecular volume, and cerebral blood flow to be protective against the cognitive impairment effect in MCI patients (15)(16)(17). It has been found that MCI patients with higher CR are able to tolerate greater brain pathology such as cortical thinning or gray matter volume atrophy as well as having more severe white matter damage than patients with lower CR at a given level of cognitive impairment (18). Recent evidences have suggested that education level and higher occupational status significantly affected the relationships between hippocampal volume and executive control function, total gray matter volume and language function in MCI patients (19).…”