Differential Effects of Cognitive Reserve on the Neurocognitive Functioning of Polysubstance Users: an Exploratory Analysis Using Mixture Regression

Vascular Endothelial Growth Factor as a Potential Biomarker of Neuroinflammation and Frontal Cognitive Impairment in Patients with Alcohol Use Disorder

(1) Background: Alcohol Use Disorder (AUD) is associated with functional disruption of several brain structures that may trigger cognitive dysfunction. One of the mechanisms of alcohol-associated cognitive impairment has been proposed to arise from its direct impact on the immune system, which culminates in the release of cytokines and chemokines which can eventually reach the brain. Alcohol can also disrupt the blood–brain barrier, facilitating the penetration of pro-inflammatory molecules throughout vascular endothelial growth factor A (VEGFA). Thus, alcohol-induced alterations in chemokines and VEGFA might contribute to the neuroinflammation and cognitive impairment associated with AUD. (2) Methods: The present cross-sectional study investigates whether patients with AUD (n = 86) present cognitive disability associated to alterations in plasma concentration of SDF-1, fractalkine, eotaxin, MCP-1, MIP-1α and VEGFA when compared to control subjects (n = 51). (3) Results: The analysis indicated that SDF-1 and MCP-1 concentrations were higher in AUD patients than in controls. Concentrations of VEGFA were higher in AUD patients with severe frontal deficits, and the score of frontal lobe functions was negatively correlated with VEGFA and fractalkine. Acute alcohol effects on VEGFA plasma levels in healthy volunteers demonstrated the induction of VEGFA release by heavy alcohol drinking. VEGFA was positively correlated with pro-inflammatory chemokines in AUD patients with frontal cognitive impairment. (4) Conclusions: we propose VEGFA/chemokine monitoring as biomarkers of potential cognitive impairment in AUD patients.

The Assessment of Cognitive Reserve: A Systematic Review of the Most Used Quantitative Measurement Methods of Cognitive Reserve for Aging

The cognitive reserve (CR) is widely accepted as the active ability to cope with brain damage, using preexisting cognitive and compensatory processes. The common CR proxies used are the number of formal years of education, intelligence quotient (IQ) or premorbid functioning, occupation attainment, and participation in leisure activities. More recently, it has employed the level of literacy and engagement in high-level cognitive demand of professional activities. This study aims to identify and summarize published methodologies to assess the CR quantitatively. We searched for published studies on PubMed, ScienceDirect, and Web of Science between September 2018 and September 2021. We only included those studies that characterized the CR assessment methodology. The search strategy identified 1,285 publications, of which 25 were included. Most of the instruments targeted proxies individually. The lack of a gold standard tool that incorporates all proxies and cognitive tests highlights the need to develop a more holistic battery for the quantitative assessment of CR. Further studies should focus on a quantitative methodology that includes all these proxies supported by normative data to improve the use of CR as a valid measure in clinical contexts.

Testing whether cognitive reserve as measured by self-rating of stimulating activities moderates the association of polysubstance use and neurocognitive disorder

Introduction: The objectives were to identify a latent factor of cognitive reserve (CR) assessed by self-rating of cognitively stimulating activities, to analyze the association between this factor and educational attainment, and to test whether CR moderates the association between polysubstance use and neurocognitive disorder (NCD). Methods: Cross-sectional data of 753 participants was collected in Mexico City. A questionnaire for self-rating of stimulating activities (work/education, leisure, physical, social, usual- and current environments) was designed. Confirmatory factor analysis was performed to test unifactoriality. This CR factor was then used within a structural equation model of moderation between recent- and years of substance use and indicators of NCD (Montreal Cognitive Assessment and an interview for subjective cognitive deficits). Results: We found acceptable goodness-of-fit values for the unifactorial model, but no association of this factor with educational attainment, nor with recent- and years of substance use (suggesting independence of CR and severity of neuropathology). We did not find a moderation effect of CR between substance use and indicators of NCD; CR was negatively associated with subjective cognitive deficits only. Conclusions: Moderation effect of self-rated CR should be further tested using direct measures of substance-induced neuropathology. Measurement of self-rated CR may complement self-reported cognitive examination.