Relevance of cognitive deterioration in early relapsing-remitting MS: a 3-year follow-up study

The contribution of paramagnetic rim and cortical lesions to physical and cognitive disability at multiple sclerosis clinical onset: evaluating the power of MRI and OCT biomarkers

BACKGROUND

In multiple sclerosis (MS), imaging biomarkers play a crucial role in characterizing the disease at the time of diagnosis. MRI and optical coherence tomography (OCT) provide readily available biomarkers that may help to define the patient's clinical profile. However, the evaluation of cortical and paramagnetic rim lesions (CL, PRL), as well as retinal atrophy, is not routinely performed in clinic.

OBJECTIVE

To identify the most significant MRI and OCT biomarkers associated with early clinical disability in MS.

METHODS

Brain, spinal cord (SC) MRI, and OCT scans were acquired from 45 patients at MS diagnosis to obtain: brain PRL and non-PRL, CL, SC lesion volumes and counts, brain volumetric metrics, SC C2-C3 cross-sectional area, and retinal layer thickness. Regression models assessed relationships with physical disability (Expanded Disability Status Scale [EDSS]) and cognitive performance (Brief International Cognitive Assessment for Multiple Sclerosis [BICAMS]).

RESULTS

In a stepwise regression (R2 = 0.526), PRL (β = 0.001, p = 0.023) and SC lesion volumes (β = 0.001, p = 0.017) were the most significant predictors of EDSS, while CL volume and age were strongly associated with BICAMS scores. Moreover, in a model where PRL and non-PRL were pooled, only the contribution of SC lesion volume was retained in EDSS prediction. OCT measures did not show associations with disability at the onset.

CONCLUSION

At MS onset, PRL and SC lesions exhibit the strongest association with physical disability, while CL strongly contribute to cognitive performance. Incorporating the evaluation of PRL and CL into the initial MS patient assessment could help define their clinical profile, thus supporting the treatment choice.

Cognitive Impairment in Multiple Sclerosis: Past, Present, and Future

Cognitive impairment in multiple sclerosis (MS) is common and can have negative effects on quality of life. The clinical presentation can be more subtle and insidious. Thus, cognitive impairment is often underrecognized by both persons with MS (PwMS) and clinicians, leading to underestimation disability due to MS. Recent evidence supports that relapses affect cognition in a similar pattern to other physical relapse symptoms and may be the only symptom of a relapse. Regular screening using validated tests for PwMS will improve the care provided and quality of life of PwMS.

Impact of sex on clinical outcome in early Multiple Sclerosis

BACKGROUND

Previous evidence suggests sex differences in the clinical course of relapsing remitting multiple sclerosis (RRMS), but comprehensive early-stage prospective studies are lacking. We aim to quantify the impact of sex on clinical outcomes in early-stage RRMS.

METHODS

Utilizing prospective cohort data, we assessed the impact of biological sex on time-to-relapse, disability progression (Expanded Disability Status Scale [EDSS]), extremity function (Nine-Hole Peg Test, Timed-25-food walk test), cognition (Paced Auditory Serial Addition Test, Symbol Digit Modalities Test), quality-of-life (Hamburg Quality of Life Questionnaire in Multiple Sclerosis, Short-Form-36), fatigue (Fatigue Severity Scale, Fatigue Scale for Motor and Cognitive functions), and depression (Beck Depression Inventory-II) in clinically isolated syndrome (CIS) or RRMS patients. Inclusion was within 12 months of symptom onset. Linear, negative binomial, mixed, and Cox models estimated male vs. female effects at the four-year follow-up including baseline-to-follow-up course.

RESULTS

We included 149 patients (65.1 % female). Eighty-five completed four-year follow-up. No sex differences in time-to-relapse emerged (HR = 0.91;95 %CI = 0.53-1.58). Males had no increased risk of EDSS worsening (OR = 0.75;95 %CI = 0.21-2.35) compared to females. Similarly, minor/no sex differences emerged in other outcomes.

CONCLUSIONS

Four years after first manifestation, neither disease activity (disability progression and relapse rate) nor patient-reported outcomes showed sex-related disparities in this early-MS-cohort.

CLINICALTRIALS

GOV IDENTIFIER

NCT01371071.

Correlation between cognitive changes and neuroradiological changes over time in multiple sclerosis: a systematic review and meta-analysis

BACKGROUND

While many studies have examined relationships of neuroimaging variables to cognitive measures in multiple sclerosis (MS), longitudinal studies are lacking. The relationship of cognitive changes to neuroradiological changes in MS is thus incompletely understood. The present study systematically reviews all studies reporting a relationship between MRI changes and cognitive changes after at least one year of follow-up.

METHOD

An extensive and methodical search of online databases was conducted to identify qualified studies until August 2023. Among various cognitive tests and magnetic resonance imaging (MRI) measures, Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT), verbal fluency, T2 lesion volume (T2LV), white matter lesion volume (WML), and grey matter volume (GMV) qualified for inclusion in a meta-analysis investigating the association of cognitive changes to neuroradiological changes.

RESULTS

We identified 35 studies that explored the link between MRI changes and changes in cognitive outcomes. Of these, twenty studies (57.14%) investigated the association between SDMT/PASAT and MRI metrics. Eleven studies (31.42%) focused on the relationship between MRI metrics and verbal learning and memory, while ten studies (28.57%) reported associations with visuospatial learning and memory. Furthermore, eight studies (22.85%) analyzed the correlation between verbal fluency and MRI measures. Only 5 were eligible for inclusion in the meta-analysis. The meta-analysis evaluated correlations between SDMT/PASAT and GMV (rs = 0.67, 95% CI 0.44-0.91), and verbal fluency and T2LV (rs = 0.35, 95% CI 0.09-0.60).

CONCLUSION

In this rigorously conducted systematic review, we found a significant association of cognitive changes, specifically SDMT/PASAT and verbal fluency, to changes in T2LV and atrophy in individuals with MS. Findings should be interpreted cautiously due to the limited amount of high-quality research, small sample sizes, and variability in study methodologies.

Teriflunomide, cognition and MRI: A longitudinal study

BACKGROUND

As cognitive impairment in multiple sclerosis (MS) is a frequent and disabling symptom, it is particularly important to identify treatments that have proven efficacy in this aspect of the disease. Several disease-modifying therapies for MS have been evaluated and shown to have a potential effect on cognition and its neurobiological correlates, but to date there is very little data on Teriflunomide (TRF). The aim of this study is to explore the influence of TRF on comprehensive cognitive function and its MRI correlations (global and focal brain volume) in relapsing-remitting multiple sclerosis (RRMS) after two years of therapy.

METHODS

Twenty-four patients with RRMS were evaluated at baseline and after two years of treatment with BCcogSEP, a French translation of the Brief Repeatable Battery (BRB-N) including 3 additional tests. We explored the performance evolution for each test and correlation with MRI data for all patients. We also differentiated MS patients with and without cognitive impairment.

RESULTS

After two years of treatment, an improvement is observed at the Selective Reminding Test for mean number of words (p = 0.044), learning (p = 0.018), and delayed recall (p = 0.002) and at GoNoGo task (p = 0.022). At MRI, the corpus callosum volume variation correlates positively with SRT total recall test (p = 0,047). Intergoup analysis shows that the evolution of group performance differs only for the SRT total recall test. The comparison of patients with or without cognitive impairment showed a clear difference in white matter substance volume (p = 0,003) and in the Percentage Brain Volume Change (p = 0,016).

CONCLUSION

Results suggest that TRF treatment in RRMS has a positive effect in cognitive function, and specifically on long term verbal memory and inhibition. Neuroimaging data suggest a link between cognition and global and focal white matter volume, particularly in the corpus callosum which is involved in anatomical disconnection syndrome and therefore brain plasticity capacities.

The Prevalence of Cognitive Impairment in Relapsing-Remitting Multiple Sclerosis: A Systematic Review and Meta-analysis

It is increasingly recognized that cognitive symptoms are a common sequelae of relapsing-remitting multiple sclerosis and are associated with adverse functional consequences. However, estimates of cognitive impairment (CIm) prevalence vary widely. This study aimed to determine the pooled prevalence of CIm among adults with RRMS and investigate moderators of prevalence rates. Following prospective registration (PROSPERO; CRD42021281815), electronic databases (Embase, Scopus, Medline, and PsycINFO) were searched from inception until March 2023. Eligible studies reported the prevalence of CIm among adults with RRMS, as determined through standardized neuropsychological testing and defined as evidence of reduced performance across at least two cognitive domains (e.g., processing speed, attention) relative to normative samples, healthy controls, or premorbid estimates. The electronic database search yielded 8695 unique records, of which 50 met selection criteria. The pooled prevalence of cognitive impairment was 32.5% (95% confidence interval 29.3-36.0%) across 5859 participants. Mean disease duration and age were significant predictors of cognitive impairment prevalence, with samples with longer disease durations and older age reporting higher prevalence rates. Studies which administered more extensive test batteries also reported significantly higher cognitive impairment prevalence. Approximately one third of adults with RRMS experience clinical levels of CIm. This finding supports the use of routine cognitive testing to enable early detection of CIm, and to identify individuals who may benefit from additional cognitive and functional support during treatment planning.

Internet-delivered lifestyle physical activity intervention for cognitive processing speed in multiple sclerosis

BACKGROUND

We propose a randomized controlled trial(RCT) of a Social Cognitive Theory-based(SCT), Internet-delivered behavioral intervention targeting lifestyle physical activity(LPA) for yielding improvements in cognitive processing speed(CPS), learning and memory(L/M), symptoms, and quality of life(QOL) among persons with mild multiple sclerosis(MS)-related ambulatory impairment who have impaired CPS.

METHODS/DESIGN

The study involves a Phase-II, parallel group, RCT design. Participants with MS(N = 300) will be randomly assigned on an equal basis(1:1) into behavioral intervention(n = 150) or attention and social contact control(n = 150) conditions. The conditions will be administered over 6-months by trained behavior coaches who will be uninvolved in screening, recruitment, random assignment, and outcome assessment. We will collect outcome data remotely every 6-months over the 12-month period(baseline, immediate follow-up, and 6-month follow-up) using a treatment blinded assessor. The primary outcome is the raw, oral Symbol Digit Modalities Test as a neuropsychological measure of CPS. The secondary outcomes include the California Verbal Learning Test-II as an objective measure of L/M, and patient-reported outcomes of fatigue, depressive symptoms, anxiety, pain, and QOL. The tertiary outcome is accelerometry as an objective, device-based measure of steps/day for generating a minimal clinically important difference(MCID) value that guides the prescription of LPA for improving CPS in clinical practice. The primary data analyses will involve intent-to-treat principles, and mixed-effects models and logistic regression.

DISCUSSION

If successful, the proposed study will provide Class I evidence for the efficacy of a theory-based, Internet-delivered behavioral intervention focusing on LPA for improving CPS and mitigating its negative impact on other outcomes in persons with MS.

CLINICALTRIALS

gov: NCT04518657.

Retinal clues for selective neuronal loss in multiple sclerosis

OBJECTIVE

The relationship between the cell body layer and the dendritic network layer of the retina and cognitive performance (CP) in MS patients has not been examined separately. The objective of this study is to predict cognitive impairment (CI) in RRMS patients and to examine the relationship between CP and ganglion cell layer (GCL), inner plexiform layer (IPL), and GCL divided by IPL (GCL/IPL).

METHODS

Ophthalmological evaluation, retinal segmentation, and Symbol Digit Modalities Test (SDMT) were performed on 102 RRMS patients and 54 healthy subjects. The relationships of GCL, IPL, and GCL/IPL with CP in eyes without a history of optic neuritis were investigated using Spearman's correlation. Models were created by accepting 1 standard deviation less of the SDMT mean of the control group as the limit for CI. The cutoff value of the GCL/IPL variable that could predict CI was calculated by ROC analysis, and the ability to accurately predict CI was tested with binary logistic regression.

RESULTS

No correlation was found between OCT parameters and CP in healthy subjects. Correlation was found between GCL thickness and GCL/IPL variable and CP in RRMS patients (r=0.235, r=0.667 respectively). A GCL/IPL value of 1.255 was able to identify CI with 81.8% sensitivity and 75.9% specificity (AUC=0.844, LR=3.38) and predicted CI with 74.5% accuracy (Nagelkerke R2=0.439).

CONCLUSION

In RRMS patients, the IPL thickness is unrelated to CP. Therewithal, the GCL/IPL-CP relationship is stronger than the GCL-CP relationship and GCL/IPL can predict CI.

Cognitive reserve proxies for individuals with intellectual developmental disability: A scoping review

BACKGROUND

Cognitive reserve (CR) has not been studied in people with Intellectual Developmental Disability, a population with a high incidence of dementia. Commonly adopted CR proxies should be adapted to reflect more specifically the experiences of people with Intellectual Developmental Disability.

METHOD

This scoping review intended to identify CR proxies relevant to people with this condition.

RESULTS

Some of these were the same already detected in a population without intellectual disabilities (education, occupation, physical activity, leisure, community and social activities); others were found to be specifically relevant for this population: type of schooling, parental educational level, environmental stimulation and living place.

CONCLUSIONS

These proxies need to be considered in studies on CR and Intellectual Developmental Disability and in clinical practice. Research on the protective effect of CR aims to encourage policies promoting lifestyle-based educational and preventive interventions and overcome participation barriers for people with Intellectual Developmental Disability.

Basal Ganglia Atrophy and Impaired Cognitive Processing Speed in Multiple Sclerosis

Impaired cognitive processing speed is among the important higher brain dysfunctions in multiple sclerosis (MS). However, the exact structural mechanisms of the dysfunction remain uncertain. This study aimed to identify the brain regions associated with the impaired cognitive processing speed in MS by comparing the cognitive processing speed, measured using the Cognitive Processing Speed Test (CogEval) z-score, and brain regional volumetric data. Altogether, 80 patients with MS (64 with relapsing-remitting MS [RRMS] and 16 with secondary progressive MS [SPMS]) were enrolled. Consequently, CogEval z-scores were worse in patients with SPMS than in those with RRMS (p=0.001). In the univariate correlation analyses, significant correlations with CogEval z-score were suggested in the MS lesion volume (p<0.001; Spearman's rank correlation test) and atrophies in the cerebral cortex (p=0.031), cerebral white matter (p=0.013), corpus callosum (p=0.001), thalamus (p=0.001), and putamen (p<0.001). Multiple linear regression analysis revealed that putamen atrophy was significantly associated with CogEval z-score (p=0.038) independent of volume in other brain regions, while thalamic atrophy was not (p=0.79). Univariate correlation analyses were further performed in each of RRMS and SPMS. None of the evaluated volumetric data indicated a significant correlation with the CogEval z-score in RRMS. Meanwhile, atrophies in the cerebral white matter (p=0.008), corpus callosum (p=0.002), putamen (p=0.011), and pallidum (p=0.017) demonstrated significant correlations with CogEval z-score in SPMS. In summary, the putamen could be an important region of atrophy contributing to the impaired cognitive speed in MS, especially in the later disease stages after a transition to SPMS.

Association of the BDNF rs6265 Polymorphism with Cognitive Impairment in Multiple Sclerosis: A Case-Control Study in Mexican Patients

Cognition is a set of brain processes that allow the individual to interact with their environment. Multiple sclerosis (MS) is a chronic inflammatory disease that affects the cerebral white matter of the brain cortex and spinal cord, leading to cognitive impairment (CI) in 40-60% of the patients. Many studies have determined that CI is linked to genetic risk factors. We aimed to evaluate the association between BDNF gene rs6265 polymorphism and cognitive impairment in Mexican patients with MS by performing a case-control study. Mestizo-Mexican patients diagnosed with MS based on McDonald's criteria were enrolled. Cases were MS patients with CI (n = 31) while controls were MS patients without CI (n = 31). To measure cognitive functioning in MS patients, a neuropsychological screening battery for MS (NSB-MS) was used. Genotyping of the rs6265 gene variant was performed using quantitative real-time PCR (qPCR) with TaqMan probes. The results showed no statistically significant differences in sociodemographic and disease variables between case and control groups. qPCR analysis showed that there were 68% Val/Val wild-type homozygotes, 29% Val/Met polymorphic heterozygotes, and 3% Met/Met polymorphic homozygotes. The presence of BDNF gene rs6265 polymorphism showed an increased probability (3.6 times) of global cognitive impairment.

Functional and structural brain MRI changes associated with cognitive worsening in multiple sclerosis: a 3-year longitudinal study

BACKGROUND

Heterogeneous processes may contribute to cognitive impairment in multiple sclerosis (MS).

OBJECTIVE

To apply a longitudinal multiparametric MRI approach to identify mechanisms associated with cognitive worsening in MS patients.

METHODS

3 T brain functional and structural MRI scans were acquired at baseline and after a median follow-up of 3.4 years in 35 MS patients and 22 healthy controls (HC). Associations between cognitive worsening (reliable change index score < - 1.25 at the Rao's battery) and longitudinal changes in regional T2-hyperintense white matter (WM) lesions, diffusion tensor microstructural WM damage, gray matter (GM) atrophy and resting state (RS) functional connectivity (FC) were explored.

RESULTS

At follow-up, HC showed no clusters of significant microstructural WM damage progression, GM atrophy or changes in RS FC. At follow-up, 10 MS patients (29%) showed cognitive worsening. Compared to cognitively stable, cognitively worsened MS patients showed more severe GM atrophy of the right anterior cingulate cortex and bilateral supplementary motor area (p < 0.001). Cognitively worsened vs cognitively stable MS patients showed also decreased RS FC in the right hippocampus of the right working memory network and in the right insula of the default mode network. Increased RS FC in the left insula of the executive control network was found in the opposite comparison (p < 0.001). No significant regional accumulation of focal WM lesions nor microstructural WM abnormalities occurred in both patients' groups.

CONCLUSIONS

GM atrophy progression in cognitively relevant brain regions combined with functional impoverishment in networks involved in cognitive functions may represent the substrates underlying cognitive worsening in MS.

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.

Current Status of Oral Disease-Modifying Treatment Effects on Cognitive Outcomes in Multiple Sclerosis: A Scoping Review

INTRODUCTION

Cognitive impairment represents one of the most hidden and disabling clinical aspects of multiple sclerosis (MS). In this regard, the major challenges are represented by the need for a comprehensive and standardised cognitive evaluation of each patient, both at disease onset and during follow-up, and by the lack of clear-cut data on the effects of treatments. In the present review, we summarize the current evidence on the effects of the available oral disease-modifying treatments (DMTs) on cognitive outcome measures.

MATERIALS AND METHODS

In this systematised review, we extract all the studies that reported longitudinally acquired cognitive outcome data on oral DMTs in MS patients.

RESULTS

We found 29 studies that evaluated at least one oral DMT, including observational studies, randomised controlled trials, and their extension studies. Most of the studies (n = 20) evaluated sphingosine-1-phosphate (S1P) modulators, while we found seven studies on dimethyl fumarate, six on teriflunomide, and one on cladribine. The most frequently used cognitive outcome measures were SDMT and PASAT. Most of the studies reported substantial stability or mild improvement in cognitive outcomes in a short-time follow-up (duration of most studies ≤2 years). A few studies also reported MRI measures of brain atrophy.

CONCLUSION

Cognitive outcomes were evaluated only in a minority of prospective studies on oral DMTs in MS patients with variable findings. More solid and numerous data are present for the S1P modulators. A standardised cognitive evaluation remains a yet unmet need to better clarify the possible positive effect of oral DMTs on cognition.

Cognitive impairment in multiple sclerosis: "classic" knowledge and recent acquisitions

Multiple sclerosis (MS) is a central nervous system (CNS) disease characterized by inflammation, axonal demyelination, and neurodegeneration, which can have a strong impact on all aspects of the life of the patient. Multiple sclerosis causes motor, sensory, cerebellar, and autonomic dysfunctions, as well as cognitive and psychoemotional impairment. The most frequently compromised cognitive domains are complex attention/information processing, memory, executive and visuospatial functions. Recently, alterations have also been evidenced in complex cognitive functions, such as social cognition, moral judgment, and decision-making. Cognitive impairment is characterized by high variability and can affect work skills, social interactions, coping strategies and more generally the quality of life of patients and their families. With the use of sensitive and easy-to-administer test batteries, an increasingly accurate and early diagnosis is feasible: this allows to determine the effectiveness of possible preventive measures, to predict the future progression of the disease and to improve the quality of life of patients. There is currently limited evidence regarding the efficacy, on cognitive impairment, of disease-modifying therapies. The most promising approach, which has received strong empirical support, is cognitive rehabilitation.

Instruments measuring change in cognitive function in multiple sclerosis: A systematic review

BACKGROUND

Multiple sclerosis (MS) is a chronic demyelinating/neurodegenerative disease associated with change in cognitive function (CF) over time. This systematic review aims to describe the instruments used to measure change in CF over time in people with MS (PwMS).

METHODS

PubMed, OVID, Web of Science, and Scopus databases were searched in English until May 2021. Articles were included if they had at least 100 participants and at least a 1-year interval between baseline and last follow-up measurement of CF. Results were quantitatively synthesized, presented in tables and risk of bias was assessed with the Newcastle-Ottawa Scale.

RESULTS

Fifty-seven articles met the inclusion criteria (41,623 PwMS and 1105 controls). An intervention (drug/rehabilitation) was assessed in 22 articles. In the studies that used a test battery, Visual and verbal learning and memory were the most frequently measured domains, but when studies that used test battery or a single test are combined, Information processing speed was the most measured. The Symbol Digit Modalities Test (SDMT) was the most frequently used test as a single test and in a test battery combined. Most studied assessed "change in CF" as cognitive decline defined as 1 or more tests measured as ≥ 1.5 SD from the study control or normative mean in a test battery at baseline and follow-up. Meta-analysis of change in SDMT scores with seven articles indicated a nonstatistically significant -0.03 (95% CI -0.14, 0.09) decrease in mean SDMT score per year.

CONCLUSION

This study highlights the slow rate of measured change in cognition in PwMS and emphasizes the lack of a gold standard test and consistency in measuring cognitive change at the population level. More sensitive testing utilizing multiple domains and longer follow-up may define subgroups where CF change follows different trajectories thus allowing targeted interventions to directly support those where CF is at greatest risk of becoming a clinically meaningful issue.

Assessing cognitive changes in multiple sclerosis: criteria for a reliable decision

INTRODUCTION

Quantifying a significant cognitive change on a neuropsychological battery is essential to assess patients' decline or recovery and offer appropriate care. The reliability of change indices is particularly important in multiple sclerosis (MS), as the course of cognitive impairment is quite unpredictable, due at least in part to substantial interindividual variability. The main objective of this study was to compare six different methods for assessing cognitive change in an MS sample: the SD method, two reliable change indices, two standardized regression-based methods (SRB), and the generalized regression-based method (GSRB).

METHOD

One hundred and twenty-three patients with clinically definite MS and 89 healthy controls underwent a battery of standardized neuropsychological tests assessing cognitive functions that are frequently affected in this disease (i.e., verbal episodic memory, working memory, processing speed and verbal fluency).

RESULTS

We observed fairly similar proportions of improvement, decline or stability in the control group whatever the method. By contrast, in the MS sample, regression-based methods with one predictor (i.e., score at T1) and four predictors (i.e., score at T1 and demographic factors: age, sex, education level) detected a significant worsening more often than the reliable change indices while the GSRB method was more consistent with the RCI methods in tasks associated with ceiling effects.

CONCLUSIONS

The interpretation of a patient's cognitive changes depends on which method is used. The (G)SRB methods appear to be relevant indicators for assessing cognitive change in MS. The addition of demographic factors does not seem to play an important role in the prediction of significant worsening in the MS sample, regardless of cognitive domain. For clinicians, an easy-to-use free shiny app is provided.

Comparative effectiveness of natalizumab on cognition in multiple sclerosis: A cohort study

BACKGROUND

Cognitive impairment occurs in 40%-70% of persons with multiple sclerosis (MS).

OBJECTIVE

To examine the effectiveness of natalizumab compared with other disease-modifying treatments (DMTs) on improving cognition as measured by the Symbol Digit Modalities Test (SDMT).

METHODS

Data were collected as part of Swedish nationwide phase IV surveillance studies (2007-2020). An increase in SDMT score by ⩾10% of the difference between maximum score possible (110) and the baseline value was defined as cognitive improvement. The likelihood of improvement was compared between natalizumab-treated individuals and individuals treated with other DMTs using mixed effect logistic regression. Trend in odds of improvement was investigated using slope analyses.

RESULTS

We included 2100 persons with relapsing-remitting MS treated with natalizumab and 2622 persons treated with other DMTs. At 6 months, 45% reached improvement. The natalizumab group showed largest odds of improvement during follow-up (odds ratio: 2.3, 95% confidence interval (CI): 1.5-3.5). The odds of improvement increased by 7% (95% CI: 6-7) per month of natalizumab treatment. The equivalent estimate was 4% (95% CI: 2-5) for other monoclonal antibodies and nonsignificant for oral or platform therapies.

CONCLUSION

Treatment with natalizumab or other monoclonal antibodies is associated with a significantly faster likelihood of cognitive improvement than platform or oral DMTs.

Women in the field of multiple sclerosis: How they contributed to paradigm shifts

History is full of women who made enormous contributions to science. While there is little to no imbalance at the early career stage, a decreasing proportion of women is found as seniority increases. In the multiple sclerosis (MS) field, 44% of first authors and only 35% of senior authors were female. So, in this review, we highlight ground-breaking research done by women in the field of MS, focusing mostly on their work as principal investigators. MS is an autoimmune disorder of the central nervous system (CNS), with evident paradigm shifts in the understating of its pathophysiology. It is known that the immune system becomes overactivated and attacks myelin sheath surrounding axons. The resulting demyelination disrupts the communication signals to and from the CNS, which causes unpredictable symptoms, depending on the neurons that are affected. Classically, MS was reported to cause mostly physical and motor disabilities. However, it is now recognized that cognitive impairment affects more than 50% of the MS patients. Another shifting paradigm was the involvement of gray matter in MS pathology, formerly considered to be a white matter disease. Additionally, the identification of different T cell immune subsets and the mechanisms underlying the involvement of B cells and peripheral macrophages provided a better understanding of the immunopathophysiological processes present in MS. Relevantly, the gut-brain axis, recognized as a bi-directional communication system between the CNS and the gut, was found to be crucial in MS. Indeed, gut microbiota influences not only different susceptibilities to MS pathology, but it can also be modulated in order to positively act in MS course. Also, after the identification of the first microRNA in 1993, the role of microRNAs has been investigated in MS, either as potential biomarkers or therapeutic agents. Finally, concerning MS therapeutical approaches, remyelination-based studies have arisen on the spotlight aiming to repair myelin loss/neuronal connectivity. Altogether, here we emphasize the new insights of remarkable women that have voiced the impact of cognitive impairment, white and gray matter pathology, immune response, and that of the CNS-peripheral interplay on MS diagnosis, progression, and/or therapy efficacy, leading to huge breakthroughs in the MS field.

Stages of brain volume loss and performance in the Brief International Cognitive Assessment for Multiple Sclerosis

BACKGROUND

Cognitive dysfunction occurs in a substantial proportion of patients with multiple sclerosis (MS), negatively affects their daily activities, and is associated with poor prognosis. Cognitive dysfunction in MS can extend across multiple cognitive domains, depending on the patterns and extent of the brain regions affected. Therefore, a combination of tests, including the Brief International Cognitive Assessment for MS (BICAMS), that assess different aspects of cognition is recommended to capture the full picture of cognitive impairment in each patient. However, the temporal relationships between the progression of the MS brain pathology and the performances in different cognitive tests remain unclear.

METHODS

Global and regional brain volume data were obtained based on T1-weighted magnetic resonance imaging from 61 patients with MS, and hierarchical cluster analysis was performed using these brain volume data. Cognitive function was assessed using the three subcomponents of the BICAMS: the Symbol Digit Modalities Test (SDMT), California Verbal Learning Test Second Edition (CVLT2), and Brief Visuospatial Memory Test-Revised (BVMTR). Clinical characteristics, patterns of regional brain volume loss, and cognitive test scores were compared among clusters.

RESULTS

Cluster analysis of the global and regional brain volume data classified patients into three clusters (Clusters 1, 2, and 3) in order of decreasing global brain volume. A comparison of the clinical profiles of the patients suggested that those in Clusters 1, 2, and 3 are in the early, intermediate, and advanced stages of MS, respectively. Pair-wise analysis of regional brain volume among the three clusters suggested brain regions where volume loss starts early and continues throughout the disease course, occurs preferentially at the early phase, or evolves relatively slowly. SDMT scores differed significantly among the three clusters, with a decrease from Clusters 1 to 3. BVMTR scores also declined in this order, whereas the CVLT2 was significantly impaired only in Cluster 3.

CONCLUSION

Our results suggest that SDMT performance declines in conjunction with brain volume loss throughout the disease course of MS. Performance in the BVMTR also declines in line with the brain volume loss, but impairment in the CVLT2 becomes particularly apparent at the late phase of MS.

A neuropsychologically based employment intervention for women with multiple sclerosis: A quasi-randomized controlled trial

OBJECTIVE

Job loss is common in multiple sclerosis (MS) and frequently associated with depression, fatigue, and cognitive dysfunction. Identifying these modifiable risk factors and providing "at-risk" women with a neuropsychologically-based intervention may improve employment outcomes. Our study seeks to investigate the utility of a neuropsychologically-based intervention with varying levels of treatment and follow-up, and evaluate treatment and employment outcomes among groups.

METHOD

In this longitudinal, quasi-randomized controlled trial, employed women with MS meeting criteria on screening measures were considered "at-risk" for job instability and randomized to one of two neuropsychological testing interventions (standard-care group received testing and phone feedback of results and recommendations; experimental group received testing and in-person feedback with subsequent care-coordinator calls from a nurse to help coordinate recommendation completion). Participants who did not meet criteria were considered "low-risk" and only followed over time.

RESULTS

56 women in the treatment groups (standard-care = 23; experimental = 33) and 63 women in the follow-only group were analyzed at 1 year. Rates of decreased employment were similar between standard-care (17.4%) and experimental (21.2%) groups (OR = .782, 95% CI .200-3.057). However, the experimental group completed significantly more treatment recommendations, t(53) = -3.237, p = .002. Rates of decreased employment were also similar between the "low-risk" (17.5%) and "at-risk" groups (19.6%), (OR = .721, 95% CI .285-1.826).

CONCLUSION

Employment outcomes were similar at 1 year between treatment groups receiving differing levels of a neuropsychologically-based intervention, however treatment adherence significantly improved in the experimental group. Treatment groups also had similar employment outcomes as compared to a "low-risk," no intervention group, suggesting that engaging in either neuropsychological intervention may have impacted job stability.

Information processing speed as a prognostic marker of physical impairment and progression in patients with multiple sclerosis

BACKGROUND

Prediction of disability progression in patients with MS (pwMS) is challenging. So far, scarce evidence exists suggesting knowledge about how cognitive performance may potentially improve prediction of physical impairment and disability progression in MS. Therefore, we wanted to assess the prognostic value of cognitive performance regarding physical impairment and disability progression in pwMS.

METHODS

85 patients (64% female; 60% relapse-remitting MS; mean age=36.78 ± 9.63 years) underwent clinical, neuropsychological (Brief Repeatable Battery for Neuropsychological Test (BRB-N)) and brain MRI (T1-weighted and T2-weighted FLAIR images) assessment at baseline and after an average of 7 years (SD=3.75) at follow-up. We assessed physical impairment and annualized disability progression (disability progression divided by follow-up duration) using the Expanded Disability Status Scale (EDSS). To compare patients with no or mild physical impairment (EDSS≤2.5) and patients with moderate to severe physical impairment (EDSS≥3.0), we used an EDSS score ≥3.0 as cut-off. Silent progression was defined by an EDSS worsening of at least 0.5 in the absence of relapses and inflammation in relapsing-remitting MS.

RESULTS

In hierarchical regression models (method "STEPWISE", forward) performance in information processing speed was a significant and independent predictor of physical impairment (EDSS≥3.0) at follow-up (model R²=0.671, b=-1.46, OR=0.23, p=0.001) and annualized disability progression (adjusted model R²=0.257, β=-0.26, 95% CI: -0.066, -0.008, p=0.012), in addition to demographics (age, education, individual follow-up time), clinical (EDSS, disease duration, clinical phenotype, annualized-relapse-rate) and MRI measures (brain volumes and T2-lesion load). In a MANCOVA controlled for age, disease duration and individual follow-up time, worse baseline performance in information processing speed was found in patients with higher EDSS at follow-up (m=-1.91, SD=1.18, p<0.001) and silent progression (m=-2.19, SD=1.01, p=0.038).

CONCLUSION

Performance in information processing speed might help to identify patients at risk for physical impairment. Therefore, neuropsychological assessment should be integrated in clinical standard care to support disease management in pwMS.

Effects of actual and imagined music-cued gait training on motor functioning and brain activity in people with multiple sclerosis: protocol of a randomised parallel multicentre trial

INTRODUCTION

Motor imagery (MI) refers to the mental rehearsal of a physical action without muscular activity. Our previous studies showed that MI combined with rhythmic-auditory cues improved walking, fatigue and quality of life (QoL) in people with multiple sclerosis (pwMS). Largest improvements were seen after music and verbally cued MI. It is unclear whether actual cued gait training achieves similar effects on walking as cued MI in pwMS. Furthermore, in pwMS it is unknown whether any of these interventions leads to changes in brain activation. The purpose of this study is therefore to compare the effects of imagined and actual cued gait training and a combination thereof on walking, brain activation patterns, fatigue, cognitive and emotional functioning in pwMS.

METHODS AND ANALYSIS

A prospective double-blind randomised parallel multicentre trial will be conducted in 132 pwMS with mild to moderate disability. Randomised into three groups, participants will receive music, metronome and verbal cueing, plus MI of walking (1), MI combined with actual gait training (2) or actual gait training (3) for 30 min, 4× per week for 4 weeks. Supported by weekly phone calls, participants will practise at home, guided by recorded instructions. Primary endpoints will be walking speed (Timed 25-Foot Walk) and distance (2 min Walk Test). Secondary endpoints will be brain activation patterns, fatigue, QoL, MI ability, anxiety, depression, cognitive functioning, music-induced motivation-to-move, pleasure, arousal and self-efficacy. Data will be collected at baseline, postintervention and 3-month follow-up. MRI reference values will be generated using 15 matched healthy controls.

ETHICS AND DISSEMINATION

This study follows the Standard Protocol Items: Recommendations for Interventional Trials-PRO Extension. Ethical approval was received from the Ethics Committees of the Medical Universities of Innsbruck (1347/2020) and Graz (33-056 ex 20/21), Austria. Results will be disseminated via national and international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

DRKS00023978.

No Changes in Functional Connectivity After Dimethyl Fumarate Treatment in Multiple Sclerosis

Introduction

Despite the increased availability of disease-modifying therapies (DMTs) for treating relapsing-remitting multiple sclerosis (RR-MS), only a few studies have evaluated DMT-associated brain functional changes.

Methods

We investigated whether significant resting-state functional connectivity (FC) changes occurred in RR-MS patients after 6 and 12 months of dimethyl fumarate (DMF) treatment using both a seed-based and data-driven approach.

Results

Thirty patients were followed up after 6 months of therapy, and 27 of them reached a 12-month follow-up. Three patients at baseline and only one after 12 months showed gadolinium-enhancing lesions. We did not find any significant FC changes after therapy at either time point. After 12 months of DMF, we observed relatively modest brain volume loss and a significant improvement in Paced Auditory Serial Addition Test 3 s and 25-Foot Walk Test scores.

Conclusion

The absence of FC changes could be due to the low degree of baseline inflammation in our patients, though we cannot exclude that more time may be required to observe such changes. No FC changes may reflect a beneficial effect of DMF therapy, as supported by conventional MRI findings and clinical improvement.

Systematic Review of the Socioeconomic Consequences in Patients With Multiple Sclerosis With Different Levels of Disability and Cognitive Function

Multiple sclerosis (MS) is a challenging and disabling condition, predominantly affecting individuals in early adulthood. MS affects the physical, cognitive, and mental health of persons suffering from the disease as well as having a great impact on their financial status and quality of life. However, there is a lack of systematic approach toward assessing the socioeconomic consequences of MS. Our objective was to systematically review analytical observational studies investigating the socioeconomic consequences in persons with MS with different levels of physical disability and cognitive function. We conducted a systematic review on socioeconomic consequences of MS with a focus on employment-, income-, work ability-, and relationship-related outcomes in persons with MS with special focus on disability and cognition. Additionally, the educational characteristics were examined. From 4,957 studies identified, 214 were assessed for eligibility and a total of 19 studies were included in this qualitative assessment; 21 different outcomes were identified. All identified studies reported higher unemployment, higher early retirement, and higher risk of unemployment in relation to higher physical disability. Also, cognitive function was found to be a predictor of employment (unemployment). The studies pointed out significant correlations between greater disability and lower earnings and higher income from benefits. A study found the same correlation in relation to cognitive function. The studies reported higher work disability in relation to higher physical disability and lower cognitive function. In conclusion, this systematic review summarizes the pronounced differences in various socioeconomic outcomes between patients with MS with regards to their physical disability and cognitive function. In addition, we identified a lack of studies with longitudinal design in this field that can provide more robust estimates with covariate adjustments, such as disease modifying treatments.

Tunisian version of the brief international cognitive assessment for multiple sclerosis: Validation and normative values

BACKGROUND

The Brief International cognitive assessment for Multiple sclerosis (BICAMS) is a specific batterie used to identify cognitive impairment in Multiple Sclerosis (MS) in a reliable and easy way. To date, for the Arabic-speaking Tunisian MS patients, there is no consensus for the use of specific cognitive batteries in MS.

OBJECTIVE

The aim of our work was to develop and validate the Tunisian version of the BICAMS (T-BICAMS) and to determine our own normative values.

MATERIAL AND METHODS

Patients diagnosed with MS and followed up in the department of Neurology of Razi Hospital were recruited and matched to healthy controls according to age, sex and educational level. T-BICAMS validity was established by comparing MS and healthy controls for symbol digit modalities test (SDMT), brief visual memory test (BVMT-R) and Tunisian verbal learning tests (TVLT) which was used instead of the California verbal learning test (CVLT-II).

RESULTS

The 104 MS patients and 104 healthy controls were comparable for age, sex and educational level. The MS group exhibited lower performances in all T-BICAMS domains compared to healthy controls: SDMT (x003Dp<10^-3), BVMT-R (p = 0.002) and TVLT (p x003D<10^-3). T-BICAMS Cronbach alpha value was 0.741. Normative values were identified for patients with MS: SDMT [39-40], BVMT-R [26-27] and TVLT [43-44]. Cognitive impairment was identified among 76 patients (73.1%). Males, lower educational levels and progressive MS were associated with a more severe cognitive impairment.

CONCLUSIONS

The current study has established the BICAMS as a valid and reliable tool for the identification of cognitive impairment in the Tunisian MS population.

Medicolegal Implications of Mild Neurocognitive Disorder

INTRODUCTION

The syndromes of mild cognitive impairment (MCI) or mild neurocognitive disorder (MiND), often prodromal to dementia (Major Neurocognitive Disorder), are characterized by acquired clinically significant changes in one or more cognitive domains despite preserved independence. Mild impairment has significant medicolegal consequences for an affected person and their care system. We review the more common etiologies of MiND and provide a systematic review of its medicolegal implications.

METHODS

We conducted a systematic review of the peer-reviewed English literature on medicolegal aspects of MCI or MiND using comprehensive search terms and expanding our review to include sources cited by these reports.

RESULTS

Impairment of memory, executive function, social cognition, judgment, insight or abstraction can alter an individual's abilities in a variety of areas that include decision making, informed consent, designation of a surrogate decision-maker such as a health care proxy, understanding and management of financial affairs, execution of a will, or safe driving.

CONCLUSION

Even mild cognitive impairment can have significant behavioral consequences. Clinicians can assist care partners and persons with MCI or MiND by alerting them to the medicolegal concerns that often accompany cognitive decline. Early recognition and discussion can help a care system manage medicolegal risk more effectively and promote thoughtful advance planning.

Cognitive Fatigue Predicts Cognitive Failure in Multiple Sclerosis Patients and Healthy Controls: A Case-Control Study

OBJECTIVE

Fatigue and cognitive deficits are frequent symptoms of multiple sclerosis (MS). However, the exact nature of their co-occurrence is not fully understood. We sought to determine the impact of cognitive and physical fatigue on subjective cognitive deficits in MS patients and healthy controls.

METHODS

Self-reports of fatigue (FSMC), depression (CES-D), cognitive deficits (CFQ), and personality traits (NEO-FFI, ANPS) among 30 MS inpatients and 30 healthy controls were analyzed using hierarchical regression models. The frequency of cognitive mistakes was used as the dependent variable and the extent of cognitive and physical fatigue as the independent variable.

RESULTS

Cognitive fatigue was the only unique and significant predictor of cognitive mistakes in both groups, explaining 13.3% of additional variance in the MS group after correcting for age, mood, and physical fatigue. Physical fatigue had no significant impact on cognitive mistakes. While age had an impact on cognitive mistakes and depression in healthy controls, this association was not significant in MS patients. Depression was significantly correlated with cognitive mistakes and cognitive fatigue in MS patients.

CONCLUSIONS

The interplay of cognitive fatigue and subjective cognitive impairment can be generalized, with the exception of the variables of age and depression, which were shown to have differing impacts on cognitive mistakes in MS patients and healthy controls, respectively. Cognitive fatigue was linked to cognitive mistakes even after correcting for overlapping items in MS patients only. Future research should further investigate the link between cognitive fatigue and attention lapses in daily life by using various objective assessments.

The adapted symbol digit modalities test: Examining the impact of response modality

BACKGROUND

Information processing speed is often impaired in neurological disorders, as well as with healthy aging. Thus, being able to accurately assess information processing speed is of high importance. One of the most commonly used tests to examine information processing speed is the Symbol Digit Modalities Test (SDMT), which has been shown to have good psychometric properties.

OBJECTIVES

The current study aims to examine differences between two response modalities, written and oral, on the performance of an adapted version of the Symbol Digit Modalities Test.

METHODS

Ninety-nine individuals completed two alternate forms of the adapted version of the SDMT (aSDMT). Participants were instructed to complete the five lines of the task as quickly and accurately as possible. On one form participants were instructed to provide their response in writing and on the other one, orally. Form and response modality (oral vs. written) were counterbalanced to control for practice effects.

RESULTS

On average, there was a significant difference between response modalities, such that participants needed more time to respond when the response modality was written. For both response modalities, time to complete each line of stimuli decreased as the task progressed. While changes in response time on the first four lines of stimuli on the oral version were not found, there was a substantial improvement in response time on the fifth line. In contrast, on the written version a gradual learning effect was observed, in which response time was the slowest on the first two lines, an intermediate response time was noted on line 3, and the fastest response time was achieved on lines four and five.

CONCLUSION

The current study demonstrates that response modality, oral versus written, can significantly impact performance efficiency (the length of time it takes to complete a task), but not accuracy (total correct responses), on a new adaptation of the SDMT, the aSDMT.

Association between symbol digit modalities test and regional cortex thickness in young adults with relapsing-remitting multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system, predominating within young adults. Cognitive disorders are common in MS and have are associated with several Magnetic Resonance Imaging (MRI) markers, especially brain atrophy. Many have found the symbol digit modalities test (SDMT) to be the most sensitive individual cognitive measure relevant to MS. However, the relationship between SDMT and regional brain cortex thickness in young adults with relapsing-remitting multiple sclerosis (YA-RRMS) has been little explored. The purpose of this study was to investigate the association between the SDMT and regional cortex thickness in YA-RRMS by FreeSurfer, which is an automatic brain structure segmentation method.

METHOD

Twenty-eight YA-RRMS patients (18-35 years old) were enrolled in the present study. Informed consent and information including gender, age, disease duration, number of relapses, annual relapse rate was collected from all patients. Clinical cognitive evaluations (SDMT and auditory verbal learning test (AVLT)) and daily performance: activities of daily living (ADL) were assessed in the present study. MRI scans were performed at the Institute of Neurosurgery of Tiantan Hospital. Twenty-eight matched healthy controls (HC) MRI data were obtained from Tiantan Hospital database. Data on thirty-four points of bilateral cortical structure thickness using statistically defined brain regions-of-interest from FreeSurfer were obtained from all participants.

RESULTS

Patients with RRMS exhibited extensively thinner cerebellar cortex compared with HC. SDMT scores were significantly correlated with AVLT subentries (IM, immediate memory; DRM, delayed recall memory; LTRM, long-term recognition memory) in YA-RRMS patients (P < 0.05). SDMT was strongly correlated with regional cortex thickness differences of the right temporal pole (r = 0.68) and bilateral parahippocampal areas (right r = 0.62; left r = 0.60), and moderately correlated with regional cortex thickness differences including the left superior temporal and right insula (r = 0.57 and 0.56, respectively) in YA-RRMS patients.

CONCLUSION

The present study has shown the SDMT is strongly correlated with selected cortex regions including the bilateral parahippocampal area and the right temporal pole which are involved in geometric structures processing.

Association of Retinal Layer Thickness With Cognition in Patients With Multiple Sclerosis

Objective

Retinal layer thickness (RLT) measured by optical coherence tomography (OCT) is considered a noninvasive, cost-efficient marker of neurodegeneration in multiple sclerosis (MS). We aimed to investigate associations of RLT with cognitive performance and its potential as indicator of cognitive status in patients with MS by performing generalized estimating equation (GEE) analyses.

Methods

In this cross-sectional study, patients with at least mild signs of cognitive impairment were examined by OCT as well as by the Brief International Cognitive Assessment for MS and tests assessing attention and executive functions (Trail Making Test [TMT] A and B). Associations of these factors were investigated using GEE models controlling for demographic and disease-related factors and correcting for multiple testing.

Results

A total of 64 patients entered the study. In the final sample (n = 50 [n = 14 excluded due to missing data or drop-outs]; n = 44 relapsing-remitting MS and n = 6 secondary progressive MS, mean Expanded Disability Status Scale score = 2.59 [SD = 1.17], disease duration [median] = 7.34 [interquartile range = 12.1]), 36.0% were cognitively impaired. RLT of the macular retinal nerve fiber layer was associated with performance in TMT-B (β = −0.259). Analyses focusing on the upper and lower tertile of RLT additionally revealed associations between macular ganglion cell-inner plexiform layer and TMT-B and verbal short-term memory and learning, respectively.

Conclusion

In patients with MS, at less advanced disease stages, RLT was especially associated with cognitive flexibility promoting OCT as a potential marker advocating further extensive neuropsychological examination.

Effect of fingolimod vs interferon treatment on OCT measurements and cognitive function in RRMS

OBJECTIVE

To explore prospectively through OCT the rate of retinal layer changes in relapsing-remitting multiple sclerosis patients followed up on fingolimod or interferon, as well as the treatments' differential effects on cognitive tests scores.

METHODS

This prospective observational study enrolled 128 stable RRMS patients treated either with fingolimod (n = 71) or interferon (n = 56). Symbol-Digit Modality Test and retinal OCT scans were obtained at baseline and every 6 to 12 months. A subgroup of patients underwent expanded cognitive tests annually (Brief visual-spatial memory-total recall, BVMT-delayed recall, and Montreal Cognitive Assessment). Retinal-OCT scans were also obtained from 22 age- and sex-matched healthy controls. Mixed effects regression was used to study annualized changes in retinal layers and cognitive function, including differences between treatment groups. Correlations between annualized changes in retinal measurements and cognitive scores were also explored.

RESULTS

Fingolimod treated patients showed no significant difference in the rate of thinning of all retinal layers when compared to healthy controls and had significantly less GCIPL thinning when compared to interferons. SDMT scores improved similarly among both RRMS treatment groups. However, interferon but not fingolimod treated patients had significant decline in MOCA and total recall scores. We also found correlations between the annualized change in GCIPL thickness and annualized change in MOCA scores, and similar correlations with annualized change in total recall scores.

CONCLUSION

Fingolimod has a potential role in reducing retinal neurodegeneration in RRMS. Longitudinal OCT measures appear to be sensitive to changes in cognitive function and may be useful for monitoring neuroprotective therapies.

A Randomized Computer-Assisted Rehabilitation Trial of Attention in Pediatric Multiple Sclerosis: A Post Hoc Analysis

Cognitive impairment (CI) is a remarkable feature in pediatric-onset multiple sclerosis (POMS). The Symbol Digit Modalities Test (SDMT) is increasingly used to explore CI in MS. Recently, a four-point worsening on the SDMT score has been demonstrated to correlate with a clinically meaningful cognitive worsening in adult MS. We conducted a post hoc analysis of a randomized computer-assisted rehabilitation trial for attention impairment in POMS to test the clinical meaningfulness of the changes in SDMT scores at the end of the trial (delta SDMT). A four-point SDMT cut-off was applied. POMS patients exposed to specific computer training (ST) and non-specific training (nST) were compared. Data of 16 POMS (9 females, age 15.75 ± 1.74 years) patients were analyzed. At the end of the trial, 25% of patients reported no clinically significant changes (−3 to 3), 12.5% a clinically significant worsening (≤−4) and 62.5% a clinically significant improvement (≥4) in the delta SDMT. The proportion of patients reporting a clinically meaningful improvement was significantly (p = 0.008) higher (100%) in patients exposed to ST in comparison to those (25%) exposed to nST. The use of the four-point SDMT cut-off may be useful to assess the clinical meaningfulness of results from cognitive rehabilitation trials.

Staging and stratifying cognitive dysfunction in multiple sclerosis

BACKGROUND

The sequence in which cognitive domains become impaired in multiple sclerosis (MS) is yet to be formally demonstrated. It is unclear whether processing speed dysfunction temporally precedes other cognitive impairments, such as memory and executive function.

OBJECTIVE

Determine the order in which different cognitive domains become impaired in MS and validate these findings using clinical and vocational outcomes.

METHODS

In a longitudinal sample of 1073 MS patients and 306 healthy controls, we measured performance on multiple, consensus-standard, neurocognitive tests. We used an event-based staging approach to model the sequence in which cognitive domains become impaired. Linear and logistic mixed-effects models were used to explore associations between stages of impairment, neurological disability, and employment status.

RESULTS

Our model suggested that the order of impairments was as follows: processing speed, visual learning, verbal learning, working memory/attention, and executive function. Stage of cognitive impairment predicted greater neurological disability, β = 0.16, SE = 0.02, p < 0.001, and probability of unemployment, β = 1.14, SE = 0.001, p < 0.001.

CONCLUSION

This is the first study to introduce a cognitive staging and stratification system for MS. Findings underscore the importance of using the Symbol Digit Modalities Test in routine screening for cognitive impairment and memory testing to assess patients later in disease evolution.

Neurocognitive impairment and social cognition in multiple sclerosis

PURPOSE/AIM OF THE STUDY

The impairment of neurocognitive functions occurs in all subtypes of multiple sclerosis, even from the earliest stages of the disease. Commonly reported manifestations of cognitive impairment include deficits in attention, conceptual reasoning, processing efficiency, information processing speed, memory (episodic and working), verbal fluency (language), and executive functions. Multiple sclerosis patients also suffer from social cognition impairment, which affects their social functioning. The objective of the current paper is to assess the effect of neurocognitive impairment and its potential correlation with social cognition performance and impairment in multiple sclerosis patients.

MATERIALS AND METHODS

An overview of the available-to-date literature on neurocognitive impairment and social cognition performance in multiple sclerosis patients by disease subtype was performed.

RESULTS

It is not clear if social cognition impairment occurs independently or secondarily to neurocognitive impairment. There are associations of variable strengths between neurocognitive and social cognition deficits and their neural basis is increasingly investigated.

CONCLUSIONS

The prompt detection of neurocognitive predictors of social cognition impairment that may be applicable to all multiple sclerosis subtypes and intervention are crucial to prevent further neural and social cognition decline in multiple sclerosis patients.

Identifying Early Neuropsychological Indicators of Cognitive Involvement in Multiple Sclerosis

Multiple sclerosis (MS) is a debilitating disease of the central nervous system that is most commonly seen in early to middle adulthood, although it can be diagnosed during childhood or later in life. While cognitive impairment can become more prevalent and severe as the disease progresses, signs of cognitive involvement can be apparent in the early stages of the disease. In this review, we discuss the prevalence and types of cognitive impairment seen in early MS, including the specific measures used to identify them, as well as the challenges in characterizing their frequency and progression. In addition to examining the progression of early cognitive involvement over time, we explore the clinical factors associated with early cognitive involvement, including demographics, level of physical disability, disease modifying therapy use, vocational status, and psychological and physical symptoms. Given the prevalence and functional impact these impairments can have for persons with MS, considerations for clinicians are provided, such as the role of early cognitive screenings and the importance of comprehensive neuropsychological assessments.

The Expanded Disability Status Scale Score and Demographic Indexes Are Correlated with the Severity of Cognitive Impairment in Multiple Sclerosis Patients

Background and Purpose

Cognitive impairment (CI) is a common symptom of multiple sclerosis (MS). Although demographic and clinical factors contribute to MS-dependent CI, previous findings have been inconsistent. This study aimed to identify the cognitive domains that are impaired in MS patients, and to determine the impacts of the Expanded Disability Status Scale (EDSS) score and other clinical and demographic factors on them domains.

Methods

This study enrolled 115 MS patients. Cognitive performance was assessed using the Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) battery. CI severity was assessed based on the number of impaired tasks in the MACFIMS battery, with impairment in two or more tasks defined as CI cases. Correlation analysis was used to determine whether factors including current age, age at disease onset, EDSS score, disease duration, relapse rate, and education level affect the severity of CI.

Results

The scores on the Paced Auditory Serial Addition Test and Delis-Kaplan Executive Function System were the most and least affected, respectively. EDSS score (r=0.438, p<0.001), current age (r=0.393, p<0.001), and disease duration (r=0.486, p<0.001) were positively correlated with CI severity, whereas education level (r=−0.527, p<0.001) had a negative correlation with CI severity, and age at disease onset and relapse rate were not correlated with CI severity (r=0.150 and p=0.107, and r=0.052 and p=0.530, respectively). However, all variables (except EDSS score) significantly predicted CI severity in a multiple regression model (p<0.001, r=0.668).

Conclusions

Information processing speed and working memory were the most commonly affected cognitive domains in the present MS patients. CI severity had strong positive correlations with current age, EDSS score, and disease duration, and a negative correlation with education level. The relapse rate and age at disease onset were not correlated with CI severity.

Montreal cognitive assessment for evaluating cognitive impairment in multiple sclerosis: a systematic review

This study aims to systematically review the evidence on the accuracy of the Montreal Cognitive Assessment (MoCA) test for evaluating the presence of cognitive impairment in patients with multiple sclerosis (MS) and to outline the quality and quantity of research evidence available about the use of MoCA in this population. We conducted a systematic literature review, searching five databases from inception until May 2020. We identified fourteen studies that met the inclusion criteria: three cross-sectional studies and two case - control studies comparing MoCA to a battery of tests, one study comparing MoCA to Mini-Mental State Examination (MMSE), and eight studies estimating the prevalence of cognitive impairment in individuals with MS. Publication period ranged from 2012 to 2020. Although the MoCA test demonstrated good sensitivity and specificity when used at the recommended threshold of 26, a lower threshold than the original cut-off was also reported to be useful for optimal screening, as it lowers false positive rates and improves diagnostic accuracy. Furthermore, in MS patients without subjective cognitive complaints, a cutoff of 27 could provide a better balance between the sensitivity and the specificity of the test. In patients with MS, the MoCA provides information on general cognitive functions disturbances. Nonetheless, more studies are required to examine the optimum cut-off score for detecting cognitive impairments in MS patients.

Classifying multiple sclerosis patients on the basis of SDMT performance using machine learning

Objective:

To build a model to predict cognitive status reflecting structural, functional, and white matter integrity changes in early multiple sclerosis (MS).

Methods:

Based on Symbol Digit Modalities Test (SDMT) performance, 183 early MS patients were assigned “lower” or “higher” performance groups. Three-dimensional (3D)-T2, T1, diffusion weighted, and resting-state magnetic resonance imaging (MRI) data were acquired in 3T. Using Random Forest, five models were trained to classify patients into two groups based on 1—demographic/clinical, 2—lesion volume/location, 3—local/global tissue volume, 4—local/global diffusion tensor imaging, and 5—whole-brain resting-state-functional-connectivity measures. In a final model, all important features from previous models were concatenated. Area under the receiver operating characteristic curve (AUC) values were calculated to evaluate classifier performance.

Results:

The highest AUC value (0.90) was achieved by concatenating all important features from neuroimaging models. The top 10 contributing variables included volumes of bilateral nucleus accumbens and right thalamus, mean diffusivity of left cingulum-angular bundle, and functional connectivity among hubs of seven large-scale networks.

Conclusion:

These results provide an indication of a non-random brain pattern mostly compromising areas involved in attentional processes specific to patients who perform worse in SDMT. High accuracy of the final model supports this pattern as a potential neuroimaging biomarker of subtle cognitive changes in early MS.

Retinal layer thinning is reflecting disability progression independent of relapse activity in multiple sclerosis

Background

PIRA (progression independent of relapse) has emerged as a term to quantify the proportion of disability worsening due to non-inflammatory neurodegenerative processes in multiple sclerosis (MS).

Objective

To determine the impact of PIRA on retinal thinning, a biomarker of neuroaxonal degeneration in MS, in comparison to traditional disability worsening and relapse.

Methods

In a 4-year, prospective observational study including 171 relapsing MS (RMS) patients, retinal thinning was determined by annual spectral-domain optical coherence tomography measuring macular ganglion-cell-and-inner-plexiform-layer (GCIPL) and peripapillary-retinal-nerve-fibre-layer (pRNFL). PIRA was defined as an expanded disability status scale (EDSS) or symbol digit modalities test (SDMT) worsening confirmed after 24 weeks with no relapse in the 30 days before or after the disability worsening.

Results

Each PIRA event was associated with a mean additional loss of GCIPL (1.8 µm) and pRNFL (1.9 µm), similar to the impact of EDSS and SDMT worsening. Overall relapse and relapse without subsequent EDSS worsening did not influence retinal thinning, while a relapse with EDSS worsening was associated with an additional loss of GCIPL (1.3 µm) and pRNFL (1.4 µm).

Conclusions

PIRA is associated with retinal thinning, likely reflecting neurodegenerative processes, not directly associated with focal inflammation. It might be a clinical measure to identify MS patients with ongoing MS-associated neurodegeneration.

Brain activity pattern changes after adaptive working memory training in multiple sclerosis

Cognitive impairment and related abnormal brain activity are common in people with multiple sclerosis (PwMS). Adaptive training based on working memory (WM) has been shown to ameliorate cognitive symptoms, although the effects at a neural level are unclear. The aim of this study was to expand the existing research on the effects of an adaptive WM rehabilitative intervention on brain functional activity in PwMS. A sample of eighteen PwMS performed an 8-week home-based cognitive rehabilitation treatment based on adaptive WM training. PwMS were assessed before and after treatment using a validated neuropsychological battery and undergoing an fMRI session while carrying out a cognitive task (i.e., Paced Visual Serial Addition Test - PVSAT). fMRI activations were compared to the activation pattern elicited by eighteen matched healthy subjects performing the same task. At baseline, we found abnormal brain activity during PVSAT in PwMS when compared to healthy subjects, with a pattern including several bilateral activation clusters. Following rehabilitation, PwMS improved cognitive performance, as evaluated by the neuropsychological battery, and showed a different activation map with clusters mainly located in the right cerebellum and in the left hemisphere. The only significant cluster in the right hemisphere was located in the inferior parietal lobule, and the BOLD signal extracted in this area significantly correlated with cognitive performance both before and after the treatment. We suggest that WM training can improve the cognitive performance and reduce the abnormal activation of PwMS by partially maintaining or even restoring brain cognitive function.

Device-Measured Physical Activity and Cognitive Processing Speed Impairment in a Large Sample of Persons with Multiple Sclerosis

OBJECTIVE

There is accumulating evidence regarding the beneficial effects of physical activity (PA) on cognitive processing speed in persons with multiple sclerosis (MS). However, one overarching limitation of this research is that researchers have not recruited samples who have the actual problem of being studied (i.e., cognitive processing speed impairment). This study examined associations between device-measured PA and cognitive processing speed in a large sample of persons with MS overall and between those with and without cognitive processing speed impairment.

METHOD

Three hundred eighty-five persons with MS underwent the oral Symbol Digit Modalities Test (SDMT) and wore an accelerometer for 7 days for PA measurement. We divided the overall sample into subsamples with (n = 140) and without (n = 245) cognitive processing speed impairment based on age, sex, and education-adjusted SDMT Z-scores.

RESULTS

After controlling for age and disability status, higher levels of device-measured PA were significantly associated with faster cognitive processing speed overall, and the association was significantly stronger among persons with MS who presented with cognitive processing speed impairment.

CONCLUSIONS

This examination provides initial cross-sectional support for informing the development of PA interventions as a possible approach for managing MS-related cognitive processing speed impairment. This highlights the importance of developing purposefully designed trials involving PA interventions for targeting cognitive processing speed as a primary end point among persons with MS with impaired cognitive processing speed.

Longitudinal cortical thinning progression differs across multiple sclerosis phenotypes and is clinically relevant: A multicentre study

Background:

Longitudinal evolution of cortical thickness (CTh) in different MS phenotypes has been rarely studied.

Aim:

To investigate the regional pattern and 1-year progression of cortical thinning in relapsing-remitting (RR) and progressive (P) MS.

Methods:

3T high-resolution T1-weighted magnetic resonance imaging (MRI) was obtained from 86 patients (75 RRMS, 11 PMS) and 34 healthy controls (HC) at three European sites at baseline and 1-year follow-up. Using FreeSurfer, baseline CTh between-group differences, longitudinal CTh changes and their correlations with clinical and MRI variables were assessed.

Results:

Baseline frontal, parietal and sensorimotor atrophy was found in MS versus HC. Such pattern was driven by RRMS, while PMS showed additional parietal, insular and sensorimotor cortical atrophy versus RRMS. At 1-year versus baseline, additional frontal and temporal cortical thinning was detected in RRMS patients, while a widespread CTh reduction was found in PMS patients (significant at time-by-group interaction vs RRMS). In MS, baseline fronto-parietal atrophy correlated with more severe disability and higher lesion volume. Baseline inferior parietal CTh decrease and 1-year temporal cortical thinning correlated with more severe disability.

Conclusion:

Parieto-temporal baseline CTh abnormalities and thinning pattern over time characterized the main MS clinical phenotypes and were associated with 1-year disability worsening.

Long-term course and morphological MRI correlates of cognitive function in multiple sclerosis

BACKGROUND

Cognitive impairment frequently occurs in patients with MS (pwMS). Magnetic resonance imaging (MRI) markers could help to identify patients at risk for decline.

OBJECTIVE

To characterize the long-term course and morphological MRI correlates of cognitive function in pwMS.

METHODS

We invited 116 pwMS who had undergone clinical, cognitive, and MRI evaluations between 2006 and 2012 (baseline, BL) to attend follow-up (FU) testing between 2016 and 2018. Disability (expanded disability status scale (EDSS)), cognition (brief repeatable battery of neuropsychological test (BRB-N)), global and regional T2-lesion load (T2-LL), brain volumes, and cortical thickness were assessed.

RESULTS

Sixty-three pwMS were willing to attend the FU (54%; median EDSS = 2, interquartile range (IQR) = 2) and did not differ from non-participating pwMS regarding BL characteristics. At BL, half of the participants showed cognitive deficits in at least one domain. Across the entire group, we observed no relevant changes in physical disability and cognition over 10 years. BL thalamic volume best predicted cognitive function at FU, in addition to age and BL cognition, explaining 67% of variance. Cognitive decliners (23.8%) were older, had longer disease duration, and a tendency for lower thalamic volume at BL.

CONCLUSION

Thalamic volume predicted FU cognitive function and distinguished declining from stable pwMS, underlining the potential of MRI to define risk groups.

What Are the Minimal Detectable Changes in SDMT and Verbal Fluency Tests for Assessing Changes in Cognitive Performance in Persons with Multiple Sclerosis and Non-Multiple Sclerosis Controls?

INTRODUCTION

Cognitive impairment is frequent in persons with multiple sclerosis (PwMS) and can impact on activities of daily living. The capacity to differentiate real changes from background statistical noise induced by human, instrumentational, and environmental variations inherent to the evaluation would improve cognitive assessments.

OBJECTIVE

To assess the short-term reproducibility of cognitive tests in non-multiple sclerosis (non-MS) persons and PwMS.

METHODS

Sixty-two PwMS and 19 non-MS persons performed 2 measurements, 1 week apart, of the Symbol Digit Modalities Test (SDMT) and phonological and semantic verbal fluency. Test-retest reliability was evaluated by the intraclass correlation coefficients (ICC) and agreement by standard error of measurement (SEM) and minimum detectable change (MDC).

RESULTS

The reliability of the cognitive variables studied had moderate to high ICC values (ICC > 0.8) in both populations. The threshold to consider a significant cognitive modification evaluated by SEM and MDC was lower in PwMS compared with non-MS persons.

CONCLUSIONS

SDMT and verbal fluency have good short-term reproducibility in PwMS. Specific SEM and MDC cutoffs based on the same design of evaluation (especially retest timing) and to the targeted pathological population (MS vs. healthy) should systematically be used to consider cognitive modification as significant in research protocol as well as in clinical practice.

Macular ganglion cell-inner plexiform layer thinning as a biomarker of disability progression in relapsing multiple sclerosis

BACKGROUND

Macular ganglion cell-inner plexiform layer (mGCIPL) is an emerging biomarker of neuroaxonal degeneration in multiple sclerosis (MS).

OBJECTIVE

We aimed to determine cut-off values of mGCIPL thinning for discriminating between progressing and stable patients in relapsing multiple sclerosis (RMS).

METHODS

This is a 3-year prospective longitudinal study on 183 RMS patients with annual optical coherence tomography. Best possible cut-off values of baseline mGCIPL and annual loss of macular ganglion cell-inner plexiform layer (aLmGCIPL) for discriminating clinically progressing (physical progression or cognitive decline) from stable patients were defined by receiver operating characteristics analysis and tested using multivariate regression models.

RESULTS

Baseline mGCIPL thickness <77 µm was associated with an increased risk (hazard ratio: 2.7, 95% confidence interval (CI): 1.5-4.7, p < 0.001) of disability progression. An aLmGCIPL cut-off ⩾1 µm accurately identified clinically progressing patients (87% sensitivity at 90% specificity) and was a strong predictor of clinical progression (odds ratio: 18.3, 95% CI: 8.8-50.3).

CONCLUSION

We present evidence that cross-sectionally measured mGCIPL thickness and annualized thinning rates of mGCIPL are able to identify clinically progressing RMS with high accuracy.

Time matters: Early-phase multiple sclerosis is accompanied by considerable impairments across multiple domains

Impairments across multiple domains are a disabling consequence of multiple sclerosis (MS). Originating from preventive medical strategies, the “time matters”-perspective has become a focal point when treating MS. In particular, early detection of physical and cognitive deficits, along with deficits in patient-reported outcomes seems crucial to further optimize both pharmacological and non-pharmacological MS treatment strategies. Therefore, this topical review investigates the level of impairments across multiple domains (physical function, cognitive function, and patient-reported outcomes) in the early stage of MS (⩽5 years since diagnosis, including clinically isolated syndrome (CIS)), when compared to matched healthy controls. Even at early disease stages, studies show impairments corresponding to 8%–34% and small-to-large numerical effect sizes (0.35–2.85) in MS/CIS patients across domains. This evidence call for early screening programs along with early interventions targeting the multiple impaired domains. This further highlights the importance of preventive initiatives preserving and/or restoring physical and cognitive reserve capacity if possible.

Cognitive Dysfunction in the Early Stages of Multiple Sclerosis-How Much and How Important?

Purpose of Review

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system that mainly affects young adults and that is one of the leading causes of disability in this age group, with cognitive impairment occurring early in the course of the disease. This article summarizes the current knowledge about cognitive dysfunction in the early phase of MS, including biomarkers, MRI correlates, and its value as a prognostic marker.

Recent Findings

New sets of neuropsychological tests have been established to screen for cognitive dysfunction more easily and accurately. Moreover, structural changes detected by brain MRI and several biomarkers found in cerebrospinal fluid and blood serum have been recently correlated with decreased cognitive performance. Additionally, factors influencing cognition in MS, such as disease-modifying therapy, mood disorders, and lifestyle, are better described.

Summary

Cognitive impairment early in the course of MS is suggested as a prognostic factor for disease progression. However, clear-cut definitions of the early stage of MS as well as unified criteria for the diagnosis of cognitive impairment are still lacking. New and more reliable tools for evaluating cognition in MS patients should be developed and introduced into everyday practice to facilitate the implementation of effective disease-modifying therapy, cognitive rehabilitation, and lifestyle management.