The relationship between cognitive reserve and cognition in healthy adults: a systematic review

Vocabulary knowledge as a reliable proxy of cognitive reserve in multiple sclerosis: a validation study

INTRODUCTION

The present study aimed to explore the suitability of the vocabulary knowledge (VOC) test as an accurate and reliable proxy of cognitive reserve (CR) by evaluating its psychometric properties and discrimination accuracy compared with other CR measures in multiple sclerosis (MS).

METHODS

Sixty-eight consecutive people with multiple sclerosis (pwMS), followed at our MS outpatient clinic, completed a clinical evaluation and neuropsychological assessment including: VOC, Brief Repeatable Battery of Neuropsychological Tests (BRB-N), Cognitive Reserve Index Questionnaire (CRIq), Beck Depression Inventory-II, and State-Trait Anxiety Inventory. Reliability, convergent and divergent validity, and discrimination accuracy of the VOC were assessed using educational level as reference standard. The possible effects of sociodemographic and clinical factors on VOC and their role in predicting global cognitive status were also explored.

RESULTS

VOC demonstrated good internal consistency (Cronbach's α = 0.894) and adequate construct validity. It showed an acceptable level of discrimination between pwMS with high and low CR, comparable to the CRIq score. Education strongly affected VOC scores, which in turn were independent of MS features. VOC emerged as an independent predictor of global cognitive status together with MS-related disability.

CONCLUSION

We demonstrated the validity of VOC as a reliable CR measure in pwMS. Thus, CR may also be estimated using fixed objective measures, independent of brain pathology and clinical features. Early CR estimation may help clinicians identify pwMS at a higher risk of cognitive decline and plan strict neuropsychological monitoring and cognitive interventions.

Cognitive reserve modulates mental health in adulthood

Cognitive Reserve (CR) reflects acquired knowledge, skills, and abilities throughout life, and it is known for modulating cognitive efficiency in healthy and clinical populations. CR, which was initially proposed to explain individual differences in the clinical presentation of dementia, has subsequently been extended to healthy ageing, showing its role in cognitive efficiency also during middle age. Recently, CR has been linked to affective processes in psychiatric conditions such as schizophrenia, major depressive and anxiety symptoms, and psychological distress, suggesting its potential role in emotional expression and regulation. Whether the role of CR in mental health extends to non-pathological adults, and whether this is only relevant in older age is not yet clear. The aim of this work was therefore to explore the relationship between CR and mental health in healthy adults, with a focus on middle adulthood (40-60). In a sample of 96 participants, we found a positive association between CR and mental health outcomes, such that a higher cognitive reserve index corresponded to fewer mental health reported symptoms. Specifically, a higher CR reflecting professional activities was associated with lower stress levels, especially in middle agers. Taken together, these data therefore suggest that engaging occupations may help maintain a robust mental health, especially by reducing stress symptoms during middle age. These results broaden previous findings suggesting that CR relates to affective components of mental health in middle aged and older adults.

Elucidating Multimodal Imaging Patterns in Accelerated Brain Aging: Heterogeneity through a Discriminant Analysis Approach Using the UK Biobank Dataset

Accelerated brain aging (ABA) intricately links with age-associated neurodegenerative and neuropsychiatric diseases, emphasizing the critical need for a nuanced exploration of heterogeneous ABA patterns. This investigation leveraged data from the UK Biobank (UKB) for a comprehensive analysis, utilizing structural magnetic resonance imaging (sMRI), diffusion magnetic resonance imaging (dMRI), and resting-state functional magnetic resonance imaging (rsfMRI) from 31,621 participants. Pre-processing employed tools from the FMRIB Software Library (FSL, version 5.0.10), FreeSurfer, DTIFIT, and MELODIC, seamlessly integrated into the UKB imaging processing pipeline. The Lasso algorithm was employed for brain-age prediction, utilizing derived phenotypes obtained from brain imaging data. Subpopulations of accelerated brain aging (ABA) and resilient brain aging (RBA) were delineated based on the error between actual age and predicted brain age. The ABA subgroup comprised 1949 subjects (experimental group), while the RBA subgroup comprised 3203 subjects (control group). Semi-supervised heterogeneity through discriminant analysis (HYDRA) refined and characterized the ABA subgroups based on distinctive neuroimaging features. HYDRA systematically stratified ABA subjects into three subtypes: SubGroup 2 exhibited extensive gray-matter atrophy, distinctive white-matter patterns, and unique connectivity features, displaying lower cognitive performance; SubGroup 3 demonstrated minimal atrophy, superior cognitive performance, and higher physical activity; and SubGroup 1 occupied an intermediate position. This investigation underscores pronounced structural and functional heterogeneity in ABA, revealing three subtypes and paving the way for personalized neuroprotective treatments for age-related neurological, neuropsychiatric, and neurodegenerative diseases.

Measures of cognitive reserve: An umbrella review

Objective: Recently, there has been a growing interest in operationalizing and measuring cognitive reserve (CR) for clinical and research purposes. This umbrella review aims to summarize the existing systematic and meta-analytic reviews about measures of CR. Method: A literature search was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and the guidelines of Aromataris et al. (2015) to identify the systematic reviews and meta-analysis involving the assessment of CR. The methodological quality of the papers included in this umbrella review was assessed with A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR-2) and Specialist Unit for Review Evidence (SURE). Results: Thirty-one reviews were identified, sixteen of which were systematic reviews, and fifteen were meta-analyses. Most of the reviews had a critically low quality, according to AMSTAR-2. The reviews included between two and 135 studies. Most of the papers focused on older adults, mainly those with dementia. CR was measured using one to six proxies, but most considered each proxy separately. The most assessed proxies of CR were education on its own, combined with occupation and/or engagement in activities or combined with parental education, bilingualism, and engagement in activities when four CR proxies were studied. Most of the studies included in higher quality reviews focused on three proxies, with education and engagement in activities being the most evaluated using CR questionnaires. Conclusion: Despite the growing interest in measuring CR, its operationalization did not improve since the last umbrella review in this field.

How to Prevent and/or Revert Alzheimer's Disease Continuum During Preclinical Phases

The development of Alzheimer's disease (AD) follows three consecutive phases: namely preclinical, prodromal or mild cognitive impairment (MCI), and dementia. In addition, the preclinical phase can be divided into subphases related to the presence of biomarkers that appear at different points before the onset of MCI. Indeed, an early risk factor could promote the appearance of additional ones through a continuum. The presence of various risk factors may trigger specific biomarkers. In this review, we comment on how modifiable risk factors for AD may be reverted, thus correlating with a possible decrease in the specific biomarkers for the disease. Finally, we discuss the development of a suitable AD prevention strategy by targeting modifiable risk factors, thereby increasing the level of "precision medicine" in healthcare systems worldwide.