The role of cognitive reserve in multiple sclerosis: A cross-sectional study in 526 patients

The relationship between biological sex, cognitive reserve, and cognition in multiple sclerosis

OBJECTIVE

Cognitive impairment is a common feature of multiple sclerosis (MS), and its severity may be influenced by several factors, such as biological sex and levels of cognitive reserve (CR). The relationship between sex, CR, and cognition has not yet been fully investigated. Therefore, the present study aimed to explore sex differences in CR building and the effect of sex and CR on cognitive performance in MS.

METHOD

233 participants underwent the Brief Repeatable Battery of Neuropsychological Tests (BRB-N), the Stroop test, and the Cognitive Reserve Scale. The t-test was performed to compare sociodemographic variables, Italian adaptation of the Cognitive Reserve Scale, and cognitive test scores between sexes. To evaluate the effect of CR and sex and their interaction on cognitive performance several models of multivariate analyses of covariance were performed (dependent variables: all subtests of Brief Repeatable Battery of Neuropsychological Tests and Stroop scores; independent variables: sex and CR). Covariates included age, Expanded Disability Status Scale, and BDI-II scores.

RESULTS

Women showed higher levels of CR, particularly in daily activities (t = -5.848, p<.001), hobbies (t = -2.591, p = .010), and social life (t = -2.362, p = .011). Sex differences were noted in verbal memory and fluency (with women outperforming men) and processing speed (with men performing better than women). Multivariate analyses revealed a nonsignificant interaction between CR and sex on cognition (Λ=.950, F(10,260)=.813, p = .617, ηp2 = .050).

CONCLUSIONS

CR and sex seemed to affect cognitive performance independently in pwMS. This highlights the importance of considering both factors in cognitive assessment, and that both sexes may benefit from specific psychoeducational training aimed at increasing CR levels.

Uncovering heterogeneous cognitive trajectories in relapsing-remitting multiple sclerosis: a longitudinal study

BACKGROUND

Cognitive impairment (CI) frequently occurs in relapsing-remitting multiple sclerosis (RRMS) and is assumed to be irreversible. Recent longitudinal studies highlighted the heterogeneity of CI in RRMS, challenging the traditional view of inevitable progression. Longitudinal studies exploring the baseline determinants of future cognitive decline are limited, and none yet explored the predictive value of patient-reported outcome measures (PROMs).

OBJECTIVE

To explore the evolutionary patterns of cognitive status in a cohort of RRMS patients initiating a new disease modifying treatment, and to determine whether PROMs may have a predictive value for future cognitive decline.

METHODS

This prospective study is a 36-month follow-up of 59 RRMS patients who underwent yearly a comprehensive, multiparametric assessment combining clinical, neuropsychological, MRI-derived metrics and a set of self-reported questionnaires. Lesion load and brain volumes were analyzed and processed by the automated MSmetrix® software (Icometrix®, Leuven, Belgium). A longitudinal logistic regression analysis was performed to investigate baseline predictors of future cognitive decline.

RESULTS

A total of 33 (56%) and 17 (35%) patients were defined as cognitively impaired at baseline and at the end of the study, respectively. Of these 33 patients, 20 showed either improvement and/or impairment in fewer cognitive domains at 36-month follow-up. Baseline physical disability as measured by EDSS was the best predictor for future cognitive decline (OR: 2.17; p = 0.03, 95% confidence interval = 1.07-4.38). None of the PROMs variables contributed to predict further cognitive decline.

CONCLUSIONS

Our findings highlight the importance of considering the evolution of CI in MS as a dynamic phenomenon with a substantial heterogeneity.

Investigating Modifiable Factors Associated with Cognitive Decline: Insights from the UK Biobank

Objectives: Given the escalating global prevalence of age-related cognitive impairments, identifying modifiable factors is crucial for developing targeted interventions. Methods: After excluding participants with dementia and substantial missing data, 453,950 individuals from UK Biobank (UKB) were included. Cognitive decline was assessed across four cognitive domains. The top 10% exhibiting the greatest decline were categorized as the "Cognitively At-Risk Population". Eighty-three potential factors from three categories were analyzed. Univariate and multivariate Cox proportional hazards models were employed to assess the independent and joint effects of these factors on cognitive decline. Population Attributable Fractions (PAFs) were calculated to estimate the potential impact of eliminating each risk category. Results: Our findings revealed a significant impact of unfavorable medical and psychiatric histories on processing speed and visual episodic memory decline (Hazard Ratio (HR) = 1.34, 95% CI: 1.20-1.51, p = 6.06 × 10⁻7; HR = 1.50, 95% CI: 1.22-1.86, p = 1.62 × 10⁻4, respectively). Furthermore, PAF analysis indicated that physiological and biochemical markers were the most critical risk category for preventing processing speed decline (PAF = 7.03%), while social and behavioral factors exerted the greatest influence on preventing visual episodic memory decline (PAF = 9.68%). Higher education, socioeconomic status, and handgrip strength emerged as protective factors, whereas high body mass index (BMI), hypertension, and depression were detrimental. Conclusions: By identifying this high-risk group and quantifying the impact of modifiable factors, this study provides valuable insights for developing targeted interventions to delay cognitive decline and improve public health outcomes in middle-aged and older adults.

Adaptation, construct validity, and test-retest reliability of the Cognitive Reserve Index Questionnaire for the Israeli multiple sclerosis population

INTRODUCTION

A common tool used to measure cognitive reserve is the Cognitive Reserve Index questionnaire (CRIq). In the present study, we aimed to adapt and determine the psychometric properties (validity and intra-rater test-retest reliability) of the Hebrew version of the CRIq in a cohort of people with multiple sclerosis (pwMS).

METHODS

Fifty pwMS (30 women aged 48.3 (SD=10.2)) completed the CRIq and the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS), which were used for validation. Secondary outcome measures included the evaluation of depression, anxiety, and perceived fatigue. Twenty-five (of the 50) pwMS were randomly selected and participated in the CRIq intra-rater test-retest reproducibility study based on a 7-12-day interval between tests.

RESULTS

The mean CRIq total was 101.8 (S.D.=13.04), which is considered at the medium level. The CRIq section scores were at a similar medium level. According to Pearson's Rho correlation analysis, the CRIq total score and sections of education, work, and leisure were significantly correlated at a medium level (Rho ranging between 0.282 to 0.415) with the SDMT score, a measurement of cognitive information processing speed. The intraclass correlation coefficient (ICC) values of the CRIq total and CRIq sections ranged between 0.942 to 0.998, indicating a strong correlation.

CONCLUSIONS

The Hebrew version of the CRIq is a reliable and valid tool for assessing cognitive reserve in pwMS, hence enabling clinicians and researchers to effectively monitor cognitive reserve in this population.

Education moderates the association between motor involvement and executive status in ALS

BACKGROUND

This study aimed to determine whether educational attainment-a common proxy of cognitive reserve (CR)-influences the association between motor and cognitive/behavioural outcomes in a large cohort of ALS patients without dementia.

METHODS

N = 726 ALS patients without FTD were assessed for motor (ALSFRS-R), cognitive (Edinburgh Cognitive and Behavioural ALS Screen, ECAS) and behavioural outcomes (ECAS-Carer Interview, ECAS-CI). CR was operationalized via educational attainment (in years). Moderation models were run on each subscale of the cognitive section of the ECAS and on the ECAS-CI by addressing ALSFRS-R as the predictor and education as the moderator.

RESULTS

Education was associated with both the ALSFRS-R and all the cognitive subscales of the ECAS, while not with the ECAS-CI. As to moderation models, a significant Education*ALSFRS-R interaction was detected solely with regard to the ECAS-Executive-with its simple slope-based decomposition revealing that higher ALSFRS-R scores were associated with higher scores on the ECAS-Executive for patients with low (p < 0.001) and average (p = 0.007), while not high, levels of education.

DISCUSSION

Education seems to moderate the association between motor involvement and executive status in ALS patients without dementia, thus possibly exerting a protective role towards both motor function and cognition in this population.

Cognitive reserve predicts long-term cognitive trajectories in relapsing-remitting multiple sclerosis

BACKGROUND

The effect of cognitive reserve (CR) on cognition in people with relapsing-remitting multiple sclerosis (pwRRMS) has been partially investigated.

OBJECTIVES

We aimed to explore the long-term cognitive trajectories of pwRRMS based on their CR, measured using the Vocabulary Knowledge Test (VOC).

METHODS

78 pwRRMS underwent a neuropsychological evaluation at baseline and after a mean follow-up of 6.5 years. We carried out several mixed-design ANCOVA to test the effect of CR on longitudinal cognitive trajectories, controlling for the effects of disability and depression. Regression analyses were performed to assess the clinical predictors of longitudinal cognitive variation.

RESULTS

At follow-up, we observed improvements in cognitive scores within pwRRMS with high CR and a decline within pwRRMS with low CR. VOC scores increased at follow-up evaluation in the whole sample, and this change was associated with the female sex. VOC emerged as the only predictor of cognitive changes over time.

CONCLUSIONS

CR, estimated by VOC, can increase over time by engaging in intellectually enriching activities, and may predict long-term cognitive outcomes in pwRRMS. The identification of pwRRMS with low CR, and therefore, most at risk of future cognitive decline, should prompt the implementation of CR enhancement interventions to delay the onset of cognitive impairment.

Patterns of cognitive decline across different multiple sclerosis clinical courses

BACKGROUND

It is still unclear whether patients with progressive MS (PMS) present a distinct pattern of cognitive impairment (CI) and different trajectories of cognitive and clinical decline compared to patients with relapsing-remitting MS (RRMS) with similar age. In addition, the role of reserve (cognitive and cerebral) in cognitive decline in the different forms of MS is not fully understood, and some studies suggest that its effects reduce in the progressive forms.

OBJECTIVE

To assess the trajectories of cognitive decline in RRMS and PMS patients with similar age, also evaluating the predictive power of baseline clinical and MRI features on cognitive outcomes at follow-up.

METHODS

Fifty-four patients were enrolled (30 PMS, 24 RRMS) and underwent brain MRI (3T - FreeSurfer and Spinal Cord Toolbox), clinical examination (Expanded Disability Status Scale - EDSS; Timed 25-Foot Walk Test - T25FW; and the Nine Hole Peg Test - 9HPT) and neuropsychological evaluation (Brief Repeatable Battery of Neuropsychological Tests - BRBN, Tower of London (TOL) test and Boston Naming Test at baseline (time 1) and after 4 years (time 2). We also evaluated cognitive and brain reserve. We defined CI as the presence of impairment in >1 domain.

RESULTS

At baseline (time 1), 37.2 % of the individuals presented CI and 52.4 % at time 2, which was more frequent in the PMS group. There was also a higher frequency of impairment in the visual memory and Information Processing Speed (IPS) cognitive domains in the PMS group in both study times. However, there were no major statistical differences between RMS/PMS groups in the evolution of clinical, cognitive and neuroimaging variables after 4 years of follow-up, except for a worse verbal memory decline (p = 0.040) and corpus callosum atrophy (p = 0.014) in PMS group. For EDSS worsening, the best predictive factor was the spinal cord area (β = -0.428), and for T25FW, the striatum volume (β = -0.467). For cognitive deterioration, striatum volume and cortical thickness were the best predictors. We found a protective effect of cognitive reserve on the decline of the domains of planning (β = 0.601) and IPS (β = 0.482) for the overall sample and the PMS group (β = 0.498 and β = 0.468, respectively).

CONCLUSIONS

We found cognitive deterioration after four years of follow-up in RRMS and PMS groups. Nevertheless, there were no major differences between these groups (with similar age, education and disease duration) in the trajectories of clinical, cognitive and neuroimaging variables during this 4-year period. We observed a protective effect of cognitive reserve in the overall sample and the PMS group.

Cognitive reserve in the recovery and rehabilitation of stroke and traumatic brain injury: A systematic review

Objective: Cognitive reserve (CR) is the brain's ability to cope with changes related to aging and/or disease. Originally introduced to explain individual differences in the clinical manifestations of dementia, CR has recently emerged as a relevant construct in stroke and traumatic brain injury (TBI). This systematic review aims to investigate whether CR could predict post-stroke and TBI clinical recovery and rehabilitation outcomes, and how different variables used to estimate CR (i.e., proxies) are related to the prognosis and effectiveness of rehabilitation in these clinical populations. Method: A search was made in Pubmed, Embase, and PsycInfo for articles published until 12 January 2023, following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) protocol guidelines. Results: 31 studies were included after completing all screening stages. Overall, results show that a higher CR was associated with a better prognosis and a more effective rehabilitation in most of the clinical aspects considered: cognitive functioning, functional, occupational, and socio-emotional abilities, as well as psychiatric and neurological scales. Conclusions: A higher CR seems to be associated with a more favorable prognosis and a better rehabilitation outcome after stroke and TBI. Results suggest that CR should be taken into account in clinical practice to make more accurate predictions about recovery and effectiveness of rehabilitation. However, some inconsistencies suggest the need for further investigations, possibly using multiple proxies for CR.

The relationship between cognitive function and functional capacity, and cognitive reserve and reaction time in patients with multiple sclerosis

BACKGROUND

 Cognitive dysfunction is frequently seen in multiple sclerosis (MS). However, there are conflicting findings regarding the factors it is associated with.

OBJECTIVE

 To investigate the relationship between aerobic capacity, strength, disability, depression, fatigue, and cognitive reserve and function.

METHODS

 The mobile applications Trail Making Test (TMT A-B), Digit Span Test (DST), Visuospatial Memory Test (VSMT), and Tap Fast were used in the cognitive function evaluation. Functional performance was assessed with the 6-minute walk test (6MWT), 5-Time Sit-to-Sand (5STS) test, and grip strength. Cognitive Reserve Index (CRI), Beck Depression Inventory, Fatigue Severity Scale (FSS), and Nottingham Health Profile were also used.

RESULTS

 A significant difference was found between the MS and control groups only in the 6MWT, STS-5, grip strength, TMT, VSMT, and Tap Fast. Good correlation was found between the TMT-A and 6MWT and physical mobility. A fair correlation was shown between grip strength, energy, and pain status. A good correlation was found between TMT-B and 6MWT, and a fair relationship with disability, cognitive reserve, and pain. Good correlation was observed between the DST and 6MWT, left grip strength, pain, and energy status; fair correlations were found between right grip strength, cognitive reserve, and physical mobility. Good correlation was found between the VSMT and energy. A fair relationship between disability, cognitive reserve, and pain was demonstrated. Good correlation was observed between the Tap Fast score and disability, 5STS, FSS, energy, and physical mobility. A fair relationship was found between pain and social isolation.

CONCLUSION

 It has been shown that cognitive performance in MS is related to disability, functional performance, cognitive reserve, fatigue, and general health.

TRIAL REGISTRATION

 NCT06084182.

Cognitive impairment in multiple sclerosis: from phenomenology to neurobiological mechanisms

Multiple sclerosis (MS) is an autoimmune-mediated disease of the central nervous system characterized by inflammation, demyelination and chronic progressive neurodegeneration. Among its broad and unpredictable range of clinical symptoms, cognitive impairment (CI) is a common and disabling feature greatly affecting the patients' quality of life. Its prevalence is 20% up to 88% with a wide variety depending on the phenotype of MS, with highest frequency and severity in primary progressive MS. Involving different cognitive domains, CI is often associated with depression and other neuropsychiatric symptoms, but usually not correlated with motor and other deficits, suggesting different pathophysiological mechanisms. While no specific neuropathological data for CI in MS are available, modern research has provided evidence that it arises from the disease-specific brain alterations. Multimodal neuroimaging, besides structural changes of cortical and deep subcortical gray and white matter, exhibited dysfunction of fronto-parietal, thalamo-hippocampal, default mode and cognition-related networks, disruption of inter-network connections and involvement of the γ-aminobutyric acid (GABA) system. This provided a conceptual framework to explain how aberrant pathophysiological processes, including oxidative stress, mitochondrial dysfunction, autoimmune reactions and disruption of essential signaling pathways predict/cause specific disorders of cognition. CI in MS is related to multi-regional patterns of cerebral disturbances, although its complex pathogenic mechanisms await further elucidation. This article, based on systematic analysis of PubMed, Google Scholar and Cochrane Library, reviews current epidemiological, clinical, neuroimaging and pathogenetic evidence that could aid early identification of CI in MS and inform about new therapeutic targets and strategies.

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.

Accelerated long-term forgetting reveals everyday memory deficits in early-stage multiple sclerosis

BACKGROUND

Patients with multiple sclerosis (MS) patients report subjective memory impairment (SMI) escaping routine neuropsychological testing. Accelerated long-term forgetting (ALF) refers to above average loss of information over an extended period of time (e.g., 7 days). This study investigates ALF in mildly affected MS patients and relates long-term memory performance to SMI.

METHODS

This prospective study included 30 patients with early MS (mean EDSS ± SD = 1.1 ± 0.9) and 30 healthy controls (HC) matched for age and education. Participants underwent ALF testing [word list (RAVLT), geometric figure (RCF), logical memory (WMS)] at three time points (baseline, 30 min, 7 days). Cognition (Montreal Cognitive Assessment), depression, SMI and fatigue were assessed. The primary outcome (PO) was defined as the quotient of the 7-day score and the 30-min memory score for the verbal (RAVLT, WMS) and figural (RCF) memory tests. The study was approved by the local ethics committee and is registered in the German Register of Clinical Studies (DRKS00025791).

RESULTS

MS patients showed impairments in PORAVLT (MS 0.66 ± 0.13 vs HC 0.82 ± 0.16; p < 0.001), whereas POWMS (MS 0.88 ± 0.15 vs HC 1.01 ± 0.12; p = 0.02) showed only a tendency. Regression analysis revealed significant associations for PORAVLT and fatigue (p = 0.034), and PORAVLT and SMI (p = 0.01) in patients but not in HC.

CONCLUSION

The ALF test quantifies SMI in MS-patients. With fatigue as a relevant associated factor, this fills the gap in objectifying SMI in MS for diagnostic purposes.

Trajectories of cognitive processing speed and physical disability over 11 years following initiation of a first multiple sclerosis disease-modulating therapy

BACKGROUND

We analysed the COMparison Between All immunoTherapies for Multiple Sclerosis (NCT03193866), a Swedish nationwide observational study in relapsing-remitting multiple sclerosis (RRMS), to identify trajectories of processing speed and physical disability after disease-modulating therapy (DMT) start.

METHODS

Using a group-modelling approach, we assessed trajectories of processing speed with oral Symbol Digit Modalities Test (SDMT) and physical disability with Expanded Disability Status Scale, from first DMT start among 1645 patients with RRMS followed during 2011-2022. We investigated predictors of trajectories using group membership as a multinomial outcome and calculated conditional probabilities linking membership across the trajectories.

RESULTS

We identified 5 stable trajectories of processing speed: low SDMT scores (mean starting values=29.9; 5.4% of population), low/medium (44.3; 25.3%), medium (52.6; 37.9%), medium/high (63.1; 25.8%) and high (72.4; 5.6%). We identified 3 physical disability trajectories: no disability/stable (0.8; 26.8%), minimal disability/stable (1.6; 58.1%) and moderate disability (3.2; 15.1%), which increased to severe disability. Older patients starting interferons were more likely than younger patients starting rituximab to be on low processing speed trajectories. Older patients starting teriflunomide, with more than one comorbidity, and a history of pain treatment were more likely to belong to the moderate/severe physical disability trajectory, relative to the no disability one. There was a strong association between processing speed and physical disability trajectories.

CONCLUSIONS

In this cohort of actively treated RRMS, patients' processing speed remained stable over the years following DMT start, whereas patients with moderate physical disability deteriorated in physical function. Nevertheless, there was a strong link between processing speed and disability after DMT start.

Systematic review of cognitive reserve in multiple sclerosis: Accounting for physical disability, fatigue, depression, and anxiety

BACKGROUND

Cognitive reserve (CR) describes an individual's ability to adapt cognitive processes in response to brain atrophy, and has been reported to explain some of the discrepancy between brain atrophy and cognitive functioning outcomes in multiple sclerosis (MS). CR in MS is typically investigated by assessing an individual's pre- and/or post-diagnosis enrichment, which includes premorbid intellectual abilities, educational level, occupational attainment, and engagement in cognitively enriching leisure activities. Common MS symptoms (e.g., physical disability, fatigue, depression, anxiety) may impact an individual's ability to engage in various CR-enhancing activities post-diagnosis. It is unknown to what extent these MS symptoms have been taken into account in MS research on CR. As such, we identified whether studies assessed CR using measures of premorbid or continuous (including post-diagnosis) enrichment. For studies investigating continuous enrichment, we identified whether studies accounted for MS-impact, which MS symptoms were accounted for, and how, and whether studies acknowledged MS symptoms as potential CR-confounds.

METHODS

Three electronic databases (PsycINFO, PubMed, Scopus) were searched. Eligible studies investigated CR proxies (e.g., estimated premorbid intellectual abilities, vocabulary knowledge, educational level, occupational attainment, cognitively enriching leisure activities, or a combination thereof) in relation to cognitive, brain atrophy or connectivity, or daily functioning outcomes in adult participants with MS. We extracted data on methods and measures used, including any MS symptoms taken into account. Objectives were addressed using frequency analyses and narrative synthesis.

RESULTS

115 studies were included in this review. 47.8% of all studies investigated continuous enrichment. Approximately half of the studies investigating continuous enrichment accounted for potential MS-impact in their analyses, with only 31.0% clearly identifying that they treated MS symptoms as potential confounds for CR-enhancement. A narrative synthesis of studies which investigated CR with and without controlling statistically for MS-impact indicated that accounting for MS symptoms may impact findings concerning the protective nature of CR.

CONCLUSION

Fewer than half of the studies investigating CR proxies in MS involved continuous enrichment. Just over half of these studies accounted for potential MS-impact in their analyses. To achieve a more complete and accurate understanding of CR in MS, future research should investigate both pre-MS and continuous enrichment. In doing so, MS symptoms and their potential impact should be considered. Establishing greater consistency and rigour across CR research in MS will be crucial to produce an evidence base for the development of interventions aimed at improving quality of care and life for pwMS.

Cognitive enrichment and education quality moderate cognitive dysfunction in black and white adults with multiple sclerosis

OBJECTIVE

To examine the extent to which three sociobehavioral proxies of cognitive reserve-years of education, education quality, and cognitive enrichment-differ in their prediction of cognitive performance among Black and White people with MS (PwMS).

METHODS

82 PwMS (Black n = 41, White n = 41) underwent a neurological examination and a neuropsychological evaluation that included tests of word recognition (Wechsler Test of Adult Reading) as well as measures of verbal memory, visuospatial memory, and processing speed (the Brief International Cognitive Assessment for MS; BICAMS). Participants rated their lifetime engagement in various cognitively-enriching activities (Cognitive Reserve Scale).

RESULTS

For the full sample, education quality and cognitive enrichment were more strongly associated with cognitive performance than were years of education. Cognitive enrichment was not associated with cognitive performance among participants with high education quality. In contrast, among participants with low education quality, cognitive enrichment was strongly associated with cognitive performance, suggesting that high engagement in cognitively-enriching activities provided similar protection to high education quality. Furthermore, among Black participants, cognitive enrichment and educational quality moderated the relationship between disability level and cognitive performance. In contrast, among White participants, cognitive enrichment did not provide additional protection beyond the buffering effect of education quality.

CONCLUSIONS

PwMS can successfully build reserve through multiple routes, including formal education or informal cognitive enrichment. Treatment for MS should incorporate cognitively-enriching activities to build resilience against cognitive decline, particularly for members of marginalized racial/ethnic groups, who are at greatest risk for poor health outcomes, and for whom years of education may not best reflect education quality.

Clinical Profiles in Multiple Sclerosis: Cognitive Reserve and Motor Impairment along Disease Duration

(i) Background: Cognitive impairment in people with multiple sclerosis (MS) has been studied in relation to certain clinical variables (e.g., motor disability and disease duration) and lifestyle factors such as cognitive reserve (CR). However, only very few studies have considered the interaction of clinical variables and cognitive reserve in preserving the integrity of the neuropsychological profile. In this paper, we hypothesised that a higher level of CR might predict good cognitive efficiency by modulating the clinical outcome of the disease. (ii) Methods: A sample of 100 participants with MS (age range 30-74), was recruited and assessed remotely with a questionnaire to measure CR and a cognitive screening test. Data were analysed through generalized additive models. (iii) Results: We found that the model analysing the interaction between CR and disease duration, and between CR and motor disability, was able to explain a significant percentage of cognitive performance. In particular, higher levels of CR predicted a better cognitive performance despite a long disease duration, unless the motor disability was severe. (iv) Conclusion: This study highlights the crucial role of CR in modulating cognitive efficiency in people with MS.

Cognitive reserve as a moderating factor between EDSS and cognition in multiple sclerosis

OBJECTIVES

It is now well recognized that brain damage and/or atrophy apparent on MRI is only moderately correlated to cognitive functioning. The cognitive reserve (CR) hypothesis has been proposed to explain this functional heterogeneity, but it has only been addressed recently in the MS literature and has not yet been thoroughly investigated. The objective of this study is to examine the protective role of CR in cognition using a standardized CR tool in a population with a wide age range.

METHODS

A neuropsychological evaluation was performed on 84 pwMS aged between 27 and 78 years old and the CR Index questionnaire (CRIq) was used to estimate CR. The EDSS scale was used to assess the degree of neurologic impairment and estimate the disease burden.

RESULTS

A moderating effect of CR was observed in the relationship between EDSS score and specific cognitive domains: processing efficiency, visuospatial learning and memory, as well as a tendency for verbal memory. In pwMS with a high level of CR, there was no negative relationship between these cognitive domains and EDSS.

CONCLUSION

The results support the protective role of CR in a sample of pwMS with a wide age range. This role seems to be limited to specific cognitive tasks that pose a greater challenge and therefore require greater adaptability.

Correlates of patient-reported cognitive performance with regard to disability

The patient-reported form of the Multiple Sclerosis Neuropsychological Questionnaire (MSNQ) assesses perceived problems attributable to cognitive and neuropsychiatric symptoms. It is inconsistently related to objective cognitive performance in multiple sclerosis (MS), while strongly correlated with depression. We assessed whether the relationship between subjective and objective cognitive screening tools is moderated by disability. Furthermore, we investigated the MSNQ as a screening tool for both cognitive impairment and depression. 275 MS patients completed the patient-reported MSNQ, two‐question screening tool for depression and Symbol Digit Modalities Test (SDMT) and were divided into Expanded Disability Status Scale (EDSS) subgroups: Low 0.0–3.0, Medium 3.5–6.0, High 6.5–9.0. MSNQ scores correlated significantly with depression but not SDMT in all subgroups. After correcting for age, sex, education, EDSS and depression, MSNQ significantly predicted SDMT in the total group, but not the subgroups. MSNQ significantly predicted a positive depression and/or cognitive impairment screen in the total group and all subgroups. The relationship between subjective and objective cognitive screening tools is not influenced by physical disability. MSNQ scores are substantially influenced by depression, and reflect cognitive function to some degree. Patient-reported cognitive measures can be useful to identify patients requiring further (neuro)psychological assessment.

Validation of the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) in the Russian Population

OBJECTIVE

Cognitive dysfunction is common in multiple sclerosis (MS). The Brief International Cognitive Assessment for MS (BICAMS) battery of tests has been suggested as a measure for the evaluation of the cognitive status of MS patients. This study aims to validate the BICAMS battery in the Russian population of MS patients.

METHODS

Age- and sex-matched MS patients (n = 98) and healthy individuals (n = 86) were included in the study. Symbol Digit Modalities Test (SDMT), California Verbal Learning Test, 2nd edition (CVLT-II) and the Brief Visuospatial Memory Test - Revised (BVMT-R) were administered to all participants. The battery was readministered 1 month later to 44 MS patients to investigate the test-retest reliability.

RESULTS

MS patients exhibited a significantly lower performance in testing with BICAMS than the control group in all three neuropsychological tests. Test-retest reliability was good for SDMT and CVLT-II (r = .82 and r = .85, respectively) and adequate for BVMT-R (r = .70). Based on the proposed criterion for impairment as z score below 1.5 SD the mean of the control group, we found that 34/98 (35%) of MS patients were found impaired at least in one cognitive domain. Patients with Expanded Disability Status Scale score ≥3.5 performed significantly worse than controls (SDMT, p < .0001; CVLT-II, p = .03; BVMT-R, p = .0004), while those with ≤3.0 scores did not.

CONCLUSION

This study demonstrates that the BICAMS battery is a valid instrument to identify cognitive impairment in MS patients and it can be recommended for routine use in the Russian Federation.

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.

Impact of Cognitive Reserve and Structural Connectivity on Cognitive Performance in Multiple Sclerosis

Background: Cognitive reserve (CR) could attenuate the impact of the brain burden on the cognition in people with multiple sclerosis (PwMS).

Objective: To explore the relationship between CR and structural brain connectivity and investigate their role on cognition in PwMS cognitively impaired (PwMS-CI) and cognitively preserved (PwMS-CP).

Methods: In this study, 181 PwMS (71% female; 42.9 ± 10.0 years) were evaluated using the Cognitive Reserve Questionnaire (CRQ), Brief Repeatable Battery of Neuropsychological tests, and MRI. Brain lesion and gray matter volumes were quantified, as was the structural network connectivity. Patients were classified as PwMS-CI (z scores = −1.5 SD in at least two tests) or PwMS-CP. Linear and multiple regression analyses were run to evaluate the association of CRQ and structural connectivity with cognition in each group. Hedges's effect size was used to compute the strength of associations.

Results: We found a very low association between CRQ scores and connectivity metrics in PwMS-CP, while in PwMS-CI, this relation was low to moderate. The multiple regression model, adjusted for age, gender, mood, lesion volume, and graph metrics (local and global efficiency, and transitivity), indicated that the CRQ (β = 0.26, 95% CI: 0.17–0.35) was associated with cognition (adj R² = 0.34) in PwMS-CP (55%). In PwMS-CI, CRQ (β = 0.18, 95% CI: 0.07–0.29), age, and network global efficiency were independently associated with cognition (adj R² = 0.55). The age- and gender-adjusted association between CRQ score and global efficiency on having an impaired cognitive status was −0.338 (OR: 0.71, p = 0.036) and −0.531 (OR: 0.59, p = 0.002), respectively.

Conclusions: CR seems to have a marginally significant effect on brain structural connectivity, observed in patients with more severe clinical impairment. It protects PwMS from cognitive decline regardless of their cognitive status, yet once cognitive impairment has set in, brain damage and aging are also influencing cognitive performance.

The Effect of Coffee and Caffeine Consumption on Patients with Multiple Sclerosis-Related Fatigue

Background: Coffee and caffeine are considered to have beneficial effects in patients with multiple sclerosis (MS), an autoimmune disease of the central nervous system (CNS) that can lead to disability and chronic fatigue. Methods: In the present study the preference in terms of coffee and caffeine consumption in patients with MS was assessed. In total the opinions of 124 MS patients were explored with a questionnaire, which was developed to investigate the consumption behavior and associated beneficial and harmful effects of coffee and caffeine concerning symptoms of fatigue. Results: Our study showed that 37.1% of the included patients experience severe symptoms of fatigue. In our cohort, fatigue was not related to age, type of diagnosis or duration of the disease. The effects of coffee did not differ between MS patients with and without fatigue. Very few side effects linked to coffee consumption were reported, and we could demonstrate that coffee consumption had no negative impact on quality of sleep. A positive effect on everyday life was observed particularly among patients with a mid-level expanded disability status scale (EDSS). The strongest effects of coffee consumption were observed regarding a better ability to concentrate while fulfilling tasks, an expanded attention span and a better structured daily routine. Conclusions: Since coffee showed no severe side effects and in the absence of an effective fatigue therapy, coffee consumption might be a therapeutic approach for selected patients with MS-related fatigue.