Higher Cognitive Reserve Research Articles

The Protective Role of Cognitive Reserve in Mild Cognitive Impairment: A Systematic Review.

Cognitive reserve (CR) represents the ability to optimize performance and functioning to cope with brain damage or disease. CR reflects the capability to adaptively and flexibly use cognitive processes and brain networks to compensate for the deterioration typical of aging. Several studies have investigated the potential role of CR in aging, especially from the perspective of preventing and protecting against dementia and Mild Cognitive Impairment (MCI). This systematic literature review aimed to investigate the role of CR as a protective factor against MCI and associated cognitive decline. The review process was conducted according to the PRISMA statement. For this purpose, ten studies were analyzed. The results of this review show that high CR is significantly associated with a reduced risk of MCI. In addition, a significant positive relationship between CR and cognitive functioning is observed when comparing subjects with MCI and healthy subjects and within people with MCI. Thus, the results confirm the positive role of cognitive reserve in mitigating cognitive impairment. The evidence from this systematic review is consistent with the theoretical models of CR. Indeed, previous research hypothesized that specific individual experiences (such as leisure activities) allow a person to acquire successful neural resources over the years to cope with cognitive decline.

Cognitive and psychological outcomes and follow-up in severely affected COVID-19 survivors admitted to a rehabilitation hospital.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) represents the most recent severe pandemic resulting in coronavirus disease 2019 (COVID-19). COVID-19 can damage the central nervous system, requiring admission to intensive care units (ICU) and aggressive treatments (long-term ventilatory assistance and sedation) to stabilize vitals. Most post-COVID-19 patients experience cognitive impairments and mood or stress disorders. We aimed to study the frequency of cognitive deficits in COVID-19 survivors, the relationship between clinical factors in the acute phase and cognitive outcomes, affective states, and quality of life. We explored cognitive reserve (CR) role, as a post-COVID-19 resilience factor. Twenty-nine COVID-19 inpatients were assessed using a neuropsychological battery, mood scales, quality of life, and social integration questionnaires. Twenty-five were retained through telephone follow-up to monitor cognitive sequelae, affective states, and reintegration levels roughly 8months after hospital discharge. We administered the Cognitive Reserve Index questionnaire. We found most patients display no cognitive deficits. When they did, multi-domain impairment occurred most frequently, especially involving executive functions. Results revealed a significant correlation between depression levels and the interval between ICU admission and tracheal tube removal. We found increased levels of depression and anxiety at follow-up, a significant relationship between resuming daily life activities, high CR, and executive functions. These findings suggest the importance of psychological support in the long term and the modulating role of cognitive reserve in quality of life after infection.

Cognitive reserve moderates the association between cerebral blood flow and language performance in older adults with mild cognitive impairment

Higher cognitive reserve (CR) may offer protection from cognitive changes associated with reduced cerebral blood flow (CBF). We investigated CR as a moderator of the effect of CBF on cognition in older adults with mild cognitive impairment (MCI; N = 46) and those who are cognitively unimpaired (CU; N = 101). Participants underwent arterial spin labeling MRI, which was used to quantify CBF in 4 a priori regions. Estimated verbal intelligence quotient (VIQ) served as a proxy for CR. Multiple linear regressions examined whether VIQ moderated associations between CBF and cognition and whether this differed by cognitive status. Outcomes included memory and language performance. There were 3-way interactions (CBF*VIQ*cognitive status) on category fluency when examining hippocampal, superior frontal, and inferior frontal CBF. Follow-up analyses revealed that, within the MCI but not CU group, there were CBF*VIQ interactions on fluency in all a priori regions examined, where there were stronger, positive associations between CBF and fluency at higher VIQ. Conclusion: In MCI, higher CR plays a role in strengthening CBF-fluency associations.

Mediation effects of cognitive, physical, and motivational reserves on cognitive performance in older people.

We study from a multidimensional perspective the different factors that help prevent the development of cognitive impairment in old aging. This study analyzed in 300 elderly subjects the relationship between cognitive reserve (CR), physical reserve (PR) and motivational reserve (MR) with cognitive impairment. This study also takes into consideration different variables (sex, age, educational level, and institutionalization) that might affect the results in the different types of reserves (CR, physical and MR) and cognitive impairment. The results show that people with a higher cognitive reserve, physical reserve and motivational reserve have less cognitive impairment. Therefore, it is important to consider measuring the CR as a variable to diagnose neurodegenerative illnesses but it is also essential to consider the physical state and physical activity, as well as the motivational dimension. With the cognitive reserve and sex variables no significant differences were observed. Age had a negative effect on strategic flexibility, but those with higher CR had better cognitive flexibility and the educational.

Cognitive reserve and individual differences in brain tumour patients.

The aim of the paper is to determine the effects of the cognitive reserve on brain tumour patients' cognitive functions and, specifically, if cognitive reserve helps patients cope with the negative effects of brain tumours on their cognitive functions. We retrospectively studied a large sample of around 700 patients, diagnosed with a brain tumour. Each received an MRI brain examination and performed a battery of tests measuring their cognitive abilities before they underwent neurosurgery. To account for the complexity of cognitive reserve, we construct our cognitive reserve proxy by combining three predictors of patients' cognitive performance, namely, patients' education, occupation, and the environment where they live. Our statistical analysis controls for the type, side, site, and size of the lesion, for fluid intelligence quotient, and for age and gender, in order to tease out the effect of cognitive reserve on each of these tests. Clinical neurological variables have the expected effects on cognitive functions. We find a robust positive effect of cognitive reserve on patients' cognitive performance. Moreover, we find that cognitive reserve modulates the effects of the volume of the lesion: the additional negative impact of an increase in the tumour size on patients' performance is less severe for patients with higher cognitive reserve. We also find substantial differences in these effects depending on the cerebral hemisphere where the lesion occurred and on the cognitive function considered. For several of these functions, the positive effect of cognitive reserve is stronger for patients with lesions in the left hemisphere than for patients whose lesions are in the right hemisphere. The development of prevention strategies and personalized rehabilitation interventions will benefit from our contribution to understanding the role of cognitive reserve, in addition to that of neurological variables, as one of the factors determining the patients' individual differences in cognitive performance caused by brain tumours.

Higher Cognitive Reserve Is Beneficial for Cognitive Performance Via Various Locus Coeruleus Functional Pathways in the Pre-Dementia Stage of Alzheimer's Disease.

Cognitive reserve (CR) shows protective effects on cognitive function in older adult and in Alzheimer's disease (AD). However, the brain mechanisms underlying the CR effect on the non-dementia AD spectrum (subjective cognitive decline (SCD) and mild cognitive impairment (MCI)) are unknown. The aim of this study was to investigate the potential moderate effect of CR on brain functional networks associated with cognitive performance. We selected 200 participants, including 48 cognitively normal (CN) and 56 SCD, and 96 patients with MCI from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Seed-based locus coeruleus functional connectivity (LC FC) was conducted to detect early brain functional changes in the non-dementia AD spectrum. CR was assessed via years of education and intelligence (IQ). The ANDI composite executive function scores (ADNI-EF) and ADNI composite memory scores (ANDI-MEM) at baseline and 24-month follow-up were used to assess cognitive performance. Compared to the CN group, the SCD group showed abnormal LC FC with the executive control network (dorsolateral prefrontal cortex, DLPFC), salience network, sensorimotor network, reward network, and hippocampus, while these alterations were inverted at the MCI stage. The LC-hippocampus FC was correlated with ADNI-MEM at baseline and follow-up, and these relationships were moderated by education. The LC-DLPFC FC was correlated with ADNI-EF at baseline, and this association was moderated by IQ. Our results manifested that higher levels of CR would confer protective effects on SCD and MCI. Furthermore, IQ and education could moderate the relationship between LC FC and cognition through different pathways.

Functional capacity and cognitive performance of adults from Argentina in cardiopulmonary rehabilitation

Functional capacity is decreased in people with Cardiovascular Diseases and Chronic Respiratory Diseases. These diseases have also been associated with cognitive dysfunction. The study examines the efficacy of a cardiopulmonary rehabilitation program in the recovery of functional capacity and analyzes whether subjects with cardiopulmonary diseases suffer from cognitive dysfunction. Participated 50 adults with medium-high education who completed a cardiopulmonary rehabilitation program of between 3 and 6 months based on physical education, nutritional education, promotion of healthy habits and medication management. Functional capacity was evaluated with the Duke index at the beginning and end of the program. Memory and language tests were also administered, for the only time, at the beginning of the program, comparing the values obtained with Argentine normative studies. The data was analyzed with the Wilcoxon test, bivariate correlations, and linear regression. Functional capacity increased significantly at the end of the program. In any case, the post-program Duke value suggests that the functional capacity of the patients continues to be affected. On the other hand, a memory test explained 10,8% of the variance in the Duke index, and there are no findings of cognitive dysfunction. The functional capacity of cardiopulmonary patients improved with the rehabilitation program, although this improvement is clinically insufficient. Better memory performance predicted greater functional capacity, which is why it is suggested to add cognitive stimulation workshops to cardiopulmonary rehabilitation programs. This sample with cardiopulmonary disease does not present cognitive dysfunction, probably due to its high cognitive reserve.

Relapse, cognitive reserve, and their relationship with cognition in first episode schizophrenia: a 3-year follow-up study

Schizophrenia is frequently characterized by the presence of multiple relapses. Cognitive impairments are core features of schizophrenia. Cognitive reserve (CR) is the ability of the brain to compensate for damage caused by pathologies such as psychotic illness. As cognition is related to CR, the study of the relationship between relapse, cognition and CR may broaden our understanding of the course of the disease. We aimed to determine whether relapse was associated with cognitive impairment, controlling for the effects of CR. Ninety-nine patients with a remitted first episode of schizophrenia or schizophreniform disorder were administered a set of neuropsychological tests to assess premorbid IQ, attention, processing speed, working memory, verbal and visual memory, executive functions and social cognition. They were followed up for 3 years (n=53) or until they relapsed (n=46). Personal and familial CR was estimated from a principal component analysis of the premorbid information gathered. Linear mixed-effects models were applied to analyse the effect of time and relapse on cognitive function, with CR as covariate. Patients who relapsed and had higher personal CR showed less deterioration in attention, whereas those with higher CR (personal and familial CR) who did not relapse showed better performance in processing speed and visual memory. Taken together, CR seems to ameliorate the negative effects of relapse on attention performance and shows a positive effect on processing speed and visual memory in those patients who did not relapse. Our results add evidence for the protective effect of CR over the course of the illness.

Cognitive Reserve Moderates the Association Between Cerebral Blood Flow and Language Performance in Older Adults with Mild Cognitive Impairment

AbstractBackgroundIt has consistently been demonstrated that individuals with higher cognitive reserve (CR) exhibit decreased risk for dementia, and differences in cerebral blood flow (CBF) among those with higher CR may offer a protective mechanism against the cognitive changes associated with dementia. We sought to investigate CR as a moderator of the effect of CBF on memory and language performance in patients with mild cognitive impairment (MCI) and those who are cognitively unimpaired (CU).MethodOlder adults from the Alzheimer’s Disease Neuroimaging Initiative (ADNI; N = 46 MCI, 101 CU) underwent neuropsychological evaluation and arterial spin labeling MRI, which was used to quantify CBF in a priori regions. Estimated VIQ from the American National Adult Reading Test was used as a CR proxy. Multiple linear regressions assessed for (1) effect of CR on cognition, (2) effect of CR on CBF, and (3) interaction between CR and CBF on cognition. Cognitive outcomes included memory (word list) and language (category fluency, naming). All models adjusted for age, gender, APOE e4 allele frequency, and education, and interactions additionally adjusted for baseline FDG and pulse pressure.ResultVIQ was not associated with memory but was positively associated with fluency and naming in both groups (ps<0.005). VIQ was not associated with CBF in either group. Individuals with MCI showed a significant interaction between VIQ and CBF on fluency across several regions, including the bilateral hippocampus (p = 0.003), bilateral inferior temporal gyrus (p = 0.008), superior frontal gyrus (p = 0.005), and inferior frontal gyrus (p<0.001). For all models, as CR increased, the magnitude of the association between CBF and performance increased. These interactions were not significant in the CU group. Models with naming or memory as the outcome variable were not significant in either group. Results remained similar when education was not adjusted for.ConclusionThese results suggest that among individuals with MCI, the association between CBF and category fluency is dependent on CR, even after adjusting for several factors. Specifically, higher CR may serve as a protective factor against the negative effect of CBF reductions on fluency. Further research is needed to clarify the role that CR plays as a moderator of CBF and cognition.

Cognitive Reserve in Mild Cognitive Impairment: structural and functional imaging correlates

AbstractBackgroundThe term “Cognitive Reserve” (CR) refers to the ability of the brain to cope with the damage in order to minimize symptomatology. Several studies have shown controversial data about functional and structural correlates of CR in normal and pathological aging, probably due to the use of different CR proxies (level of education, occupational complexity, participation in leisure activities, IQ, verbal abilities or intelligence, heterogeneous fMRI tasks). The aim of this study was to investigate imaging correlates of different aspects of CR in a sample of patients with Mild Cognitive Impairment (MCI).MethodPatients with a diagnosis of MCI and young onset of cognitive symptoms (< 65) answered the Cognitive Reserve Index questionnaire (CRIq) aimed at measuring cognitive reserve acquired during lifetime. Patients also underwent multimodal Magnetic Resonance Imaging (MRI) on a 3T scanner including high‐resolution T1 and functional MRI sequences acquired at rest (resting fMRI). CRIq‐Total score and single subscores (CRIq‐Education, ‐WorkingActivity and ‐LeisureTime) were related to regional grey matter (GM) volume, whole brain fractional anisotropy (FA) and functional connectivity of resting‐state networks (RSNs) using, respectively, Voxel Based Morphometry (VBM), Tract‐Based Spatial Statistics (TBSS), and independent component analysis of resting fMRI (MELODIC).ResultThirty‐nine patients were recruited. The median CRIq‐Total, ‐Education, ‐WorkingActivity and ‐LeisureTime scores were respectively 102, 97, 105 and 105. VBM correlational analysis showed no significant results. TBSS revealed a negative correlation between CRIq‐LeisureTime and FA of the body of corpus callosum. Resting‐fMRI analyses revealed negative correlations between CRIq scores and functional connectivity, involving particularly frontal and temporal areas.ConclusionIn patients with MCI, cognitive reserve relates to functional connectivity of fronto‐temporal areas rather than to structural variability (grey matter atrophy or white matter microstructural integrity). The negative correlations found between functional connectivity and CRIq scores shows that patients with high cognitive reserve may not need to increase functional connectivity.

A Cognitive Reserve Network That Moderates the Relationship Between Alzheimer’s Disease Pathology and Cognition

AbstractBackgroundThe new consensus definition of cognitive reserve (CR) provides a framework to study individual differences in cognitive functioning relative to aging and disease. CR denotes a property of the brain that allows for better than expected cognitive performance given the degree of age‐related brain changes or disease. More specifically, individual differences in patterns of brain activity during fMRI tasks might explain the differential susceptibility to pathological burden.MethodAccording to the consensus definitions, we sought to identify and quantify CR from fMRI novelty‐contrast maps in a large multi‐centric sample (DELCODE) consisting of 215 participants with SCD, 79 with MCI, 30 with AD dementia, 56 AD relatives and 156 cognitively normal controls (CN). CSF amyloid‐42/40 ratio, CSF p‐tau and hippocampal volume (ATN) were reduced to a single number, representing a (Alzheimer’s) disease progression (DP) score. To identify a CR network, voxel‐wise linear regression models determined where functional task‐activation moderates the relationship between DP and cognition. Finally, task‐related activity within the CR network was extracted to obtain individual fMRI‐based CR scores.ResultThe DP score showed a strong negative quadratic association with baseline memory scores. CR voxels, in which higher or lower activation were associated with better cognition, weakening the effect of DP, were mainly located within the novelty network. They included lateral‐occipital and superior‐parietal regions, lingual and fusiform gyrus, cuneus and small parts of cingulate. While there was no association between the CR score and cognition in CNs, higher CR scores in MCI and AD patients were related to higher PACC5 scores.ConclusionWe established a DP score that collapses the ATN measures into a single number, while retaining its deleterious effect on an individual’s memory score. Furthermore, a newly identified task‐dependent CR network could be used to establish a CR score, which was related to higher PACC5 scores in MCI and AD patients, suggesting a functional compensation mechanism at later stages of AD that is not yet present in CN. Thus, targeted alteration of brain activity might be a promising route to modify cognitive trajectories in MCI and AD patients. Further, detailed examination of individuals with high CR might reveal additional disease‐modifying factors.

Cognitive Reserve Modulates Brain Structure and Cortical Architecture in the Alzheimer's Disease.

Cognitive reserve (CR) explains the individual resilience to neurodegeneration. The present study investigated the effect of CR in modulating brain cortical architecture. 278 individuals [110 Alzheimer's disease (AD), 104 amnestic mild cognitive impairment (aMCI) due to AD, 64 healthy subjects (HS)] underwent a neuropsychological evaluation and 3T-MRI. Cortical thickness (CTh) and fractal dimension (FD) were assessed. Years of formal education were used as an index of CR by which participants were divided into high and low CR (HCR and LCR). Within-group differences in cortical architecture were assessed as a function of CR. Associations between cognitive scores and cortical measures were also evaluated. aMCI-HCR compared to aMCI-LCR patients showed significant decrease of CTh in the right temporal and in the left prefrontal lobe. Moreover, they showed increased FD in the right temporal and in the left temporo-parietal lobes. Patients with AD-HCR showed reduced CTh in several brain areas and reduced FD in the left temporal cortices when compared with AD-LCR subjects. HS-HCR showed a significant increase of CTh in prefrontal areas bilaterally, and in the right parieto-occipital cortices. Finally, aMCI-HCR showed significant positive associations between brain measures and memory and executive performance. CR modulates the cortical architecture at pre-dementia stage only. Indeed, only patients with aMCI showed both atrophy (likely due to neurodegeneration) alongside richer brain folding (likely due to reserve mechanisms) in temporo-parietal areas. This opposite trend was not observed in AD and HS. Our data confirm the existence of a limited time-window for CR modulation at the aMCI stage.

Cognitive reserve and risk of mobility impairment in older adults.

Cognitive reserve (CR) protects against cognitive decline and dementia but its relation to mobility impairment has not been established. To address this important gap in the literature, we conducted a longitudinal investigation to test the hypothesis that higher baseline CR was associated with a lower risk of developing mobility impairment in older adults. Participants were dementia-free older adults who received brain magnetic resonance imaging and had gait speed assessments during follow-up. Using the residuals approach, CR was computed as the variance in the Modified Mini-Mental Status Examination total score, that was left after accounting for structural brain integrity, education, and race. Mobility impairment was defined using a validated cutoff score in gait speed of 0.8 m/s. Logistic regression models using general estimating equations were utilized to examine longitudinal associations between baseline CR and the risk of developing mobility impairment across repeated assessments. Of the participants (n=237; mean age=82 years; %female=56%) who were free of mobility impairment at baseline, 103 developed mobility impairment during follow-up (mean=3.1 years). Higher CR at baseline was associated with a lower risk of developing incident mobility impairment-odds ratio (OR)=0.819, 0.67-0.98, p=0.038 (unadjusted); OR=0.815, 0.67-0.99, p=0.04 (adjusted for socio-demographic variables and depression); OR=0.819, 0.68-0.88, p=0.035 (adjusted for illness history); OR=0.824, 0.68-0.99, p=0.045 (adjusted for white matter hyperintensities); OR=0.795, 0.65-0.95, p=0.016 (adjusted for falls history). Higher CR at baseline was protective against developing incident mobility impairment during follow-up among community-residing older adults.

Effect of cognitive reserve on amnestic mild cognitive impairment due to Alzheimer's disease defined by fluorodeoxyglucose-positron emission tomography.

This study aimed to investigate the effect of cognitive reserve (CR) on the rate of cognitive decline and cerebral glucose metabolism in amnestic mild cognitive impairment (MCI) using the Study on Diagnosis of Early Alzheimer’s Disease-Japan (SEAD-J) dataset. The patients in SEAD-J underwent cognitive tests and fluorodeoxyglucose-positron emission tomography (FDG-PET). MCI to be studied was classified as amnestic MCI due to Alzheimer’s disease (AD) with neurodegeneration. A total of 57 patients were visually interpreted as having an AD pattern (P1 pattern, Silverman’s classification). The 57 individuals showing the P1 pattern were divided into a high-education group (years of school education ≥13, N = 18) and a low-education group (years of school education ≤12, N = 39). Voxel-based statistical parametric mapping revealed more severe hypometabolism in the high-education group than in the low-education group. Glucose metabolism in the hippocampus and temporoparietal area was inversely associated with the years of school education in the high- and low-education groups (N = 57). General linear mixed model analyses demonstrated that cognitive decline was more rapid in the high-education group during 3-year follow-up. These results suggest that the cerebral glucose metabolism is lower and cognitive function declines faster in patients with high CR of amnestic MCI due to AD defined by FDG-PET.

Avoidant Coping Is Associated with Quality of Life in Persons with Multiple Sclerosis with High Cognitive Reserve

The goal of this study was to determine the impact of the relationship between cognitive reserve and coping strategy on quality of life (QoL) outcomes in persons with MS (PwMS) across multiple domains. We examined the effect of the interactions between coping style and cognitive reserve on QoL and disease burden in 97 persons with MS (PwMS). Coping strategy, either active or avoidant, was measured using the COPE inventory. We defined cognitive reserve as a composite measure of years of education and scores on the Shipley-2 Vocabulary subtest. QoL and disease burden were assessed using the Functional Assessment of MS (FAMS) scale and the Expanded Disability Status Scale, respectively. We examined both the FAMS individual subscales and the overall QoL score. For those with higher cognitive reserve, greater avoidant coping was associated with lower QoL for the thinking and fatigue subscale (p < 0.001) and poorer overall QoL (p = 0.03); greater active coping was associated with poorer QoL for mobility (p = 0.001). However, these associations did not hold for those with lower cognitive reserve. Furthermore, there were no associations between coping strategy and cognitive reserve with disease burden. This study extends previous findings by demonstrating that avoidant coping, rather than active coping, is associated with poorer thinking and fatigue and overall QoL only for PwMS with greater cognitive reserve. Counseling PwMS on the impact of coping strategies on QoL outcomes, especially for those with greater cognitive reserve, may improve quality of life outcomes in this population.

Lifestyle factors in multiple sclerosis disability progression and silent brain damage: A cross-sectional study

ObjectiveTo determine the association between lifestyle risk factors with 1/ the Multiple Sclerosis Severity Score (MSSS) and 2/ ongoing subclinical brain damage in non-active MS patients on high-efficacy treatment. MethodsCross-sectional study in persons with Multiple Sclerosis (PwMS) investigating lifestyle factors including cognitive reserve (CR), physical activity (PA), smoking status, alcohol use, dietary habits, body mass index (BMI), blood pressure (BP) and cholesterol ratio. Data were collected through validated questionnaires, clinical and laboratory examination. Serum Neurofilament light chain (sNfL) levels were used as a proxy for ongoing brain damage in a subgroup of persons with non-active MS on high-efficacy treatment. Multiple regression analysis (MRA) models explored the relationship between lifestyle factors with the MSSS score and sNfL. Results351 PwMS were included (43.04 ± 11.77 years, 69.8% female). Higher CR and PA were associated with a lower MSSS; overweight or obesity and higher systolic BP with a higher MSSS. The MRA model explained 22.2% of the variance for MSSS (R².255, adjusted R².222). Higher BMI and BP were related to lower sNfL. Twenty-3% (R².279, adjusted R².230) of the variance was explained in the MRA model for sNfL. ConclusionOur study suggests an association between a ‘brain healthy lifestyle’ with disability progression in MS. A cognitive and physical active lifestyle alongside a normal body weight and blood pressure may help to prevent future disability in MS. Longitudinal and interventional research is necessary to gain insight in the causal pathway of these risk factors in preventing disability progression in MS.

Age-Dependent Association Between Cognitive Reserve Proxy and Longitudinal White Matter Microstructure in Older Adults.

ObjectiveThis study examined the association of lifetime experiences, measured by a cognitive reserve (CR) composite score composed of years of education, literacy, and vocabulary measures, to level and rate of change in white matter microstructure, as assessed by diffusion tensor imaging (DTI) measures. We also examined whether the relationship between the proxy CR composite score and white matter microstructure was modified by participant age, APOE-ε4 genetic status, and level of vascular risk.MethodsA sample of 192 non-demented (n = 166 cognitively normal, n = 26 mild cognitive impairment) older adults [mean age = 70.17 (SD = 8.5) years] from the BIOCARD study underwent longitudinal DTI (mean follow-up = 2.5 years, max = 4.7 years). White matter microstructure was quantified by fractional anisotropy (FA) and radial diffusivity (RD) values in global white matter tracts and medial temporal lobe (MTL) white matter tracts.ResultsUsing longitudinal linear mixed effect models, we found that FA decreased over time and RD increased over time in both the global and MTL DTI composites, but the rate of change in these DTI measures was not related to level of CR. However, there were significant interactions between the CR composite score and age for global RD in the full sample, and for global FA, global RD, and MTL RD among those with normal cognition. These interactions indicated that among participants with a lower baseline age, higher CR composite scores were associated with higher FA and lower RD values, while among participants with higher age at baseline, higher CR composite scores were associated with lower FA and higher RD values. Furthermore, these relationships were not modified by APOE-ε4 genotype or level of vascular risk.ConclusionThe association between level of CR and DTI measures differs by age, suggesting a possible neuroprotective effect of CR among late middle-aged adults that shifts to a compensatory effect among older adults.

Risk and Protective Factors of Psychological Distress in Patients Who Recovered From COVID-19: The Role of Cognitive Reserve.

Recent studies reported the development of psychological distress symptoms in patients who recovered from COVID-19. However, evidence is still scarce and new data are needed to define the exact risk and protective factors that can explain the variability in symptoms manifestation. In this study, we enrolled 257 patients who recovered from COVID-19 and we evaluated the levels of psychological distress through the Symptoms Checklist-90-R scale. Data concerning illness-related variables were collected from medical records, while the presence of subjective cognitive difficulties, both before and after the illness, as well as the level of the cognitive reserve (CR), were assessed over a clinical interview. Results revealed that being female and reporting the presence of subjective cognitive difficulties after COVID-19 were associated with higher levels of psychological distress. At the same time, being admitted to the hospital and having a high CR were protective factors. Adding new information to this emerging research field, our results highlight the importance of a complete psychological and cognitive assessment in patients with COVID-19.

Phonemic fluency in post-ICU patients after severe COVID-19 infection: The role of cognitive reserve

IntroductionCognitive function may be impaired in COVID-19 patients, especially in executive functions such as phonemic fluency. Among risk factors, inflammation during hospitalization is related with worse cognitive performance in the long term. On the other side, it has been shown that cognitive reserve (CR) protects against cognitive impairment associated with brain damage, psychiatric disorders and neurodegenerative diseases.ObjectivesOur aim is to study the protective role of cognitive reserve in phonemic fluency to inflammation after SARS-CoV-2 infection.MethodsWe enrolled a cohort of 102 severe SARS-CoV-2 survivors after Intensive Care Unit (ICU) discharge and 58 agreed to participate in this 6-month follow-up study. Patients with previously known cognitive impairment were excluded. Demographic, clinical and laboratory data were collected. To assess the phonemic fluency, we used the Controlled Oral Word Association Test (COWAT) controlling the effects of age and education. Inflammation was recorded according to the number of days with high CRP. ANCOVA analyses were used to test the effect of interaction between medical variables and cognitive reserve on phonemic fluency.ResultsThe COVID-19 inflammation interacted with CR in phonemic fluency (F= 6.47, p= 0.01), with worse performance in patients with low CR (mean 16.7 (10.2-23.3)) than those with high CR (mean 37.7 (34.3-41.2)) in function of number of days with high PCR during ICU stay.ConclusionsThe role of the cognitive reserve is important to reduce the cognitive impairment related with COVID-19 inflammation in post-ICU patients.DisclosureNo significant relationships.

Cognitive reserve, neurocognitive performance, and high-order resting-state networks in cognitively unimpaired aging

Cognitive Reserve (CR) is considered a protective factor during the aging process. However, although CR is a multifactorial construct, it has been operationalized in a unitary way (years of formal education or IQ). In the present study, a validated measure to categorize CR holistically (Cognitive Reserve Index Questionnaire) was used to evaluate the resting-state functional connectivity in 77 cognitively unimpaired participants aged 50 years and over with high and low CR, and matched brain global atrophy levels. The connectivity of networks linked to attentional (Dorsal Attention Network -DAN-) and executive (Frontal-Parietal Control Network -FPCN-) processes were evaluated by the combination of Independent Component Analysis and seed-based approaches, since these networks have been proposed as candidates to underlie the protective effect of CR in the aging context. Participants with high CR showed an increase of the connectivity in the FPCN and a decrease in the DAN with respect to the low CR group, correlating with neuropsychological scores and supporting that high CR is related to a better neurocognitive preservation during aging.