Neuropsychology of Multiple Sclerosis: Looking Back and Moving Forward

Pegylated chitosan nanoparticles of fluoxetine enhance cognitive performance and hippocampal brain derived neurotrophic factor levels in a rat model of local demyelination

Cognitive impairment is a common feature in neurodegenerative diseases such as multiple sclerosis (MS). This study aims to explore the potential of enhancing the beneficial effects of fluoxetine (FLX), a neuroprotective agent known for its ability to increase neural plasticity by utilizing nanoparticles. The study specifically focuses on the synthesis and evaluation of PEGylated chitosan nanoparticles of FLX and its effect on demyelination and the subsequent cognitive impairment (CI) in the hippocampus of rats induced by local injection of lysophosphatidylcholine (LPC). Chitosan/polyethylene glycol nanoparticles were synthesized, and their properties were analyzed. Demyelination was induced in rats via hippocampal injections of lysolecithin. Behavioral assessments included open field maze, elevated plus maze, and novel object recognition memory (NORM) tests. Hippocampal levels of insulin-like growth factor (IGF-1) and brain-derived neurotrophic factor (BDNF) were measured using enzyme-linked immunoassay (ELISA). The extent of remyelination was quantified using Luxol fast blue staining. Nanoparticle size measured 240.2 nm with 53 % encapsulation efficacy. Drug release exhibited a slow pattern, with 76 % released within 4 h. Nanoparticle-treated rats displayed reduced anxiety-like behavior, improved memory, increased BDNF levels, and a reduced extent of demyelination, with no change in IGF- levels. In addition, FLX -loaded chitosan nanoparticles had better effect on cognitive improvement, BDNF levels in the hippocampus that FLX. Altering pharmacokinetics and possibly pharmacodynamics. These findings highlight the potential of innovative drug delivery systems, encouraging further research in this direction.

A qualitative study exploring how vocational rehabilitation for people with multiple sclerosis can be integrated within existing healthcare services in the United Kingdom

BACKGROUND

To explore how a vocational rehabilitation (VR) intervention can be integrated within existing healthcare services for people with multiple sclerosis (MS) in the United Kingdom (UK) National Health Service (NHS).

METHODS

Data from 37 semi-structured interviews with 22 people with MS, eight employers, and seven healthcare professionals were analysed using a framework method informed by the Consolidated Framework for Implementation Research and an intervention logic model.

RESULTS

Four themes were identified relating to the structure of current NHS services, how to improve access to and awareness of VR services, the collaboration between internal and external networks, and the benefits of integrating VR within the NHS services. Participants identified several implementation barriers such as poor links with external organisations, staffing issues, and lack of funding. To overcome these barriers, participants suggested enablers such as technology (e.g., apps or online assessments) and collaboration with third-sector organisations to reduce the pressure on the NHS.

CONCLUSION

Significant organisational changes are required to ensure a successful implementation of a VR intervention within current NHS services. Despite this, the NHS was seen as a trustworthy organisation to offer support that can optimise the health and professional lives of people with MS.

Quality of reporting health behaviors for multiple sclerosis (QuoRH-MS): A scoping review to inform intervention planning and improve consistency of reporting

BACKGROUND

Multiple sclerosis (MS) is a neurological condition that necessitates a multidisciplinary approach to aid those living with MS in managing their disease. Health behavior, or lifestyle modification, is an emerging approach to MS self-management. MS researchers utilize measurement tools to ensure that interventions are best suited to the outcomes, thereby potentially influencing practice. The aim of this study was to investigate which tools are being used for health behavior management studies in people living with MS and develop an aid for tool selection.

METHODS

A scoping review guided by the PRISMA-Sc checklist and the JBI manual for evidence synthesis was employed with a systematic search strategy executed across four scientific databases: Medline, PubMed, CINAHL, and Cochrane Libraries. The types of assessment tools used were extracted from the included studies. Each tool was categorized into the health behavior intervention discipline (nutrition, exercise, and psychology) and then subcategorized by the tool's purpose. The frequency of use was determined for each tool. Reporting of validation of the assessment tools were collated to inform a tool selection checklist.

RESULTS

The review identified a total of 248 tools (12 nutrition, 55 exercise, and 119 psychology unique reports) from 166 studies. Seventy-seven multidimensional tools were identified including measures of quality of life, fatigue, and functional scales. Only 88 studies (53%) referred to the validity of the tools. The most commonly reported tools were the dietary habits questionnaire (n = 4, nutrition), 6-minute walk test (n = 17, exercise), Symbol Digits and Modalities Test, and Hospital Anxiety and Depression Scale (n = 15 each, psychology) with the Expanded Disability Status Scale reported 43 times.

CONCLUSION

Evidence from interventions may inform practice for health professionals. This review provides insights into the range of tools reported across health behavior intervention studies for MS and offers a guide toward more consistent reporting of study methods.

Anomia in left hemisphere stroke, multiple sclerosis and Parkinson's disease - a comparative study

PURPOSE

To explore quantitative and qualitative features of anomia in participants with left-hemisphere stroke, Parkinson's disease, or multiple sclerosis.

MATERIALS AND METHODS

This descriptive cross-sectional study compares signs of anomia within and across participants (n = 87), divided into four groups; moderate to severe anomia after stroke (MSAS, n = 19), mild anomia after stroke (MAS, n = 22), PD (n = 19) and MS (n = 27). Aspects analysed include naming accuracy and speed, the nature of incorrect responses, semantic and phonemic verbal fluency, information content in re-telling, and the relationship between test results and self-reports on word-finding difficulties and communicative participation.

RESULTS

All groups had impaired verbal fluency, prolonged response times and reduced information content in re-telling. The MSAS group had significantly more signs of anomia than the other groups. Results from the other groups overlapped on a MAS-PD-MS continuum. Both semantically and phonologically incorrect responses were common in the stroke groups, while semantically incorrect ones predominated in the PD and MS groups. All four groups reported a similar negative impact on self-perceived communicative participation. Correlations between self-reports and test results were inconsistent.

CONCLUSIONS

Anomia features have quantitative and qualitative similarities and differences across neurological conditions.

Increased levels of advanced oxidation protein products (AOPPs) were associated with nociceptive behavior and clinical scores in an experimental progressive autoimmune encephalomyelitis model (PMS-EAE)

Multiple sclerosis (MS) is a neurodegenerative disease that affects the central nervous system (CNS) generating neuropathic pain and anxiety. Primary progressive MS (PPMS) is the most disabling clinical form, and the patients present an intense neurodegenerative process. In this context, the advanced oxidation protein products (AOPPs) are oxidized compounds and their accumulation in plasma has been related to clinical disability in MS patients. However, the involvement of AOPPs in neuropathic pain- and anxiety-like symptoms was not previously evaluated. To assess this, female mice C57BL/6J were used to induce progressive experimental autoimmune encephalomyelitis (PMS-EAE). Clinical score, weight, strength of plantar pressure, rotarod test, mechanical allodynia, and cold hypersensitivity were evaluated before induction (baseline) and on days 7th, 10th, and 14th post-immunization. We assessed nest building, open field, and elevated plus-maze tests 13 days post-immunization. Animals were killed at 14 days post-immunization; then, AOPPs levels, NADPH oxidase, and myeloperoxidase (MPO) activity were measured in the prefrontal cortex, hippocampus, and spinal cord samples. The clinical score increased 14th post-immunization without changes in weight and mobility. Reduced paw strength, mechanical allodynia, and cold allodynia increased in the PMS-EAE animals. PMS-EAE mice showed spontaneous nociception and anxiety-like behavior. AOPPs concentration, NADPH oxidase, and MPO activity increase in CNS structures. Multivariate analyses indicated that the rise of AOPPs levels, NADPH oxidase, and MPO activity influenced the clinical score and cold allodynia. Thus, we indicated the association between non-stimuli painful perception, anxiety-like, and CNS oxidative damage in the PMS-EAE model.

Association Between Disease-Modifying Therapy and Information Processing Speed in Multiple Sclerosis

BACKGROUND

Cognitive impairment (CI) is common in multiple sclerosis (MS). Processing speed (PS) is often affected, making it an ideal target for monitoring CI. This study aims to evaluate the association between disease-modifying therapy (DMT) use and intensity and longitudinal changes in Processing Speed Test (PST) scores for individuals with MS.

METHODS

A retrospective analysis of individual PST scores at a single MS center was conducted. Individuals with 2 or more PST assessments were included. Scores on the PST were compared longitudinally between those who had been on a DMT for 2 or more years and those who had been off a DMT for 2 or more years and between those on high-efficacy DMTs and those on low-/moderate-efficacy DMTs. A linear regression model was approximated to evaluate the rate of cognitive change over time. A propensity score adjustment was conducted using a multivariable logistic regression.

RESULTS

The cohort was 642 individuals, 539 on DMT and 103 off DMT. Median age and disease duration was 49.7 (IQR 42.4-57.9) and 16.6 years (IQR 9.3-23.0) in the DMT group, and 58.9 (IQR 52.2-65.3) and 20.0 years (IQR 14.1-31.4) in the non-DMT group. Both cohorts were predominantly female (75% DMT, 79.6% non-DMT), with a mean of 4 assessments (IQR 3-5), and an average monitoring duration of 1.9 years (1.2-2.4) in the DMT group, and 1.8 years (1.4-2.4) in the non-DMT group. After adjusting for multiple factors, DMT status and intensity were not found to be significant predictors of longitudinal PST change.

CONCLUSIONS

Neither DMT status nor intensity was a significant predictor of cognitive processing speed over a period of approximately 2 years. Future prospective studies are needed to further support these findings.

Utility of the Brief Assessment of Cognitive Health (BACH) computerized screening tool in identifying MS-related cognitive impairment

BACKGROUND

Current guidelines recommend that individuals with MS are screened annually for processing speed deficits, often using the Symbol Digit Modalities Test (SDMT). However, given the heterogeneity of cognitive deficits in individuals with MS, other screening measures that assess a range of cognitive domains are necessary. The current cross-sectional study aimed to examine the ability of the computerized, self-administered Brief Assessment of Cognitive Health (BACH) screening measure to detect the presence of cognitive impairment in adults with MS as determined by performance on a standard neuropsychological test battery.

METHODS

Seventy-two individuals with MS completed the BACH and a comprehensive neuropsychological test battery. Receiver operating characteristic (ROC) analyses were conducted to investigate the ability of the BACH to identify cognitively impaired and cognitively intact individuals. ROC analyses were also conducted to compare the ability of the SDMT to discriminate between cognitively intact and cognitively impaired groups as a comparison with the BACH.

RESULTS

Cognitive impairment was observed in 56 % of the sample. The BACH showed acceptable ability to discriminate between cognitively intact and cognitively impaired groups (AUC = 0.78). Additionally, the BACH was able to adequately predict cognitive impairment in domains other than processing speed (AUC = 0.71). The SDMT also demonstrated adequate utility in identifying individuals with cognitive impairment (AUC = 0.73); however, the SDMT was not able to adequately predict cognitive impairment in domains other than processing speed (AUC = 0.56).

CONCLUSION

The BACH showed adequate ability to detect cognitive impairment in individuals with MS. The BACH was able to identify impairments across various assessed cognitive domains, including individuals with and without processing speed deficits.

Auditory Test of Processing Speed: Preliminary validation of a smartphone-based test of mental speed

BACKGROUND

The Symbol Digit Modalities Test (SDMT) is a gold-standard measure of cognitive efficiency and processing speed for people with multiple sclerosis (PwMS) but relies on vision and oculomotor function.

OBJECTIVES

To develop and validate a new processing speed test with minimal memory involvement and no eye function requirements.

METHODS

We created an Auditory Test of Processing Speed (ATOPS). A total of 122 PwMS, of whom 33 were severely disabled (median Expanded Disability Status Scale 8.0) and 37 healthy volunteers (HVs), were enrolled. We assessed sensitivity to discriminate MS participants from HVs, convergent validity between ATOPS and SDMT, sensitivity to discriminate between cognitively impaired (CI) and cognitively preserved (CP) MS participants, and correlations with MS pathology (overall brain lesion burden). Acceptability was examined with completion rates and participant ratings of ATOPS.

RESULTS

ATOPS discriminated PwMS from HVs (d = 0.739-0.856), correlated with SDMT (|r| = 0.528-0.587), discriminated between CI and CP PwMS (d = 0.623-0.776), and correlated with lesion burden (r = 0.332-0.436). All groups indicated high favorability of ATOPS and severely disabled MS patients could be assessed by ATOPS more frequently than by SDMT (100% vs. 72.4% completion).

CONCLUSIONS

ATOPS is a novel, accessible, and acceptable cognitive processing speed test that may be useful in clinical and/or research settings.

Non-pharmacological randomized intervention trial for the management of neuropsychological symptoms in outpatients with progressive multiple sclerosis

PURPOSE

Despite typically more pronounced cognitive and mental health issues in progressive disease courses of multiple sclerosis (PMS), rehabilitation research in this subgroup is rare. The efficacy of two non-pharmacological interventions with positive results from prior investigations was therefore examined in PMS specifically.

METHODS

Persons with PMS (pwPMS) received either computerized cognitive training (BrainStim), standardized cognitive-behavioral group sessions (Metacognitive Training [MaTiMS]), or a combination of both in an ambulatory setting. Neuropsychological assessment was conducted before and after the four-week intervention.

RESULTS

37 participants (13 with primary/24 with secondary PMS, meanage = 52.87, SDage = 7.11, meanEDSS = 4.02, SDEDSS = 1.35) entered analyses. The BrainStim group improved in immediate and delayed verbal memory, recognition, verbal working memory, and perceived cognitive deficits while experiencing increased anxiety post-intervention. MaTiMS participants reported high program satisfaction and less cognitive difficulties at retest. The Combination group performed better in immediate and delayed verbal memory, and in information processing speed after training. Descriptive data further indicated positive effects on anxiety and depression in the MaTiMS and Combination group.

CONCLUSIONS

While objective cognitive performance improved when explicitly trained, psychoeducative sessions contributed to subjective mental health. The combination of both approaches is thus suggested, considering the specific needs of pwPMS treated in an ambulatory setting.

Neuropsychological rehabilitation in patients with relapsing-remitting multiple sclerosis: a systematic review

Introduction: Multiple sclerosis (MS) is an autoimmune, chronic, inflammatory and demyelinating disease that affects the Central Nervous System (CNS). It is the most common disabling neurological disease in young patients not caused by traumatic shock. Depending on how symptoms appear and how often they occur, there are different subtypes of MS. One of them is the relapsing-remitting phenotype (R-R), which the symptoms appear in the form of isolated outbreaks which, little by little, are causing the increase of the disease and its sequelae. MS encompasses a wide variety of symptoms, including possible cognitive impairment. In the literature there is no clear methodology and a defined and structured consensus to carry out neuropsychological rehabilitation processes in this group.Aim: This study aims to review and synthesize the available scientific evidence about the neuropsychological intervention on cognitive impairment of people with multiple sclerosis, relapsing-remitting subtype.Methods: Keywords for database search (Pubmed and Wos) were established, as well as inclusion and exclusion criteria. Then, the articles were selected according to inclusion and exclusion criteria; methodological quality criteria were applied. Articles published in the last 10 years were included.Results: Fifteen articles that met the established criteria were selected. Most of these studies identify as effective their cognitive rehabilitation programs, some of them showed changes in neural structures after rehabilitation.Discussion: It seems that cognitive rehabilitation is effective in influencing cognitive deterioration in R-R MS. This highlights the importance of neuropsychological evaluation and intervention from the early stages of the disease.

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.

Trail Making Test Could Predict Impairment in Cognitive Domains in Patients with Multiple Sclerosis: A Study of Diagnostic Accuracy

OBJECTIVE

Cognitive impairment (CI) and executive dysfunction (ED) are prevalent in patients with multiple sclerosis (PwMS). The Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) is the gold standard neuropsychological battery (NPB) for detecting CI. Delis-Kaplan Executive Function System (DKEFS) NPB evaluates ED. We aimed to find practical test(s) from DKEFS with acceptable diagnostic utility for early detection of impairment in cognitive and executive domains.

METHODS

Cognitive and executive tasks, physical disability, and depression scores of 30 PwMS were assessed (17 women, age: 38.1). Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT), and Controlled Oral Word Association Test (COWAT) from MACFIMS and Trail Making Test (TMT), Design Fluency Test (DFT), and Verbal Fluency Test (VFT) from DKEFS were selected. The association between patients' characteristics and performance in tests, and diagnostic accuracy of DKEFS tests in detecting impairment in cognitive tasks were evaluated, using Pearson correlation and receiver operator characteristic curve analyses, respectively.

RESULTS

A significant correlation was found between disease duration and SDMT and TMT subtests. Expanded Disability Status Scale was significantly related to SDMT, VFT-switching, and TMT subtests. Beck Depression Inventory was significantly related to DFT. TMT-switching detected abnormalities in SDMT and PASAT with 100% sensitivity, 93.3% (for SDMT), and 85.7% specificity (for PASAT). TMT-letter showed 100% sensitivity and 90% specificity in identifying abnormalities in COWAT.

CONCLUSIONS

TMT, particularly the switching condition, is a practical paper-based test that could predict impairment in cognitive tasks. Clinicians may use TMT as a screening tool among PwMS.

High levels of kappa free light chain synthesis predict cognitive decline in relapsing-remitting multiple sclerosis

Background

Evolving evidence suggests that measurement of cerebrospinal fluid (CSF) kappa free light chain (KFLC) synthesis has high diagnostic sensitivity and specificity for multiple sclerosis (MS), but its prognostic ability is less investigated. The usefulness of KFLC in predicting cognitive impairment (CI) is still unknown.

Methods

In a monocentric longitudinal retrospecitve cohort study, KFLC-index ([CSF KFLC/serum KFLC]/[CSF albumin/serum albumin]) measured by latex-enhanced immunonephelometry was prospectively determined as part of the diagnostic workup in patients with early relapsing-remitting MS (RRMS, n=77). The ability of KFLC-index to predict information processing speed (IPS) worsening as assessed with the symbol digit modalities test (SDMT) was investigated in univariable and multivariable models.

Results

In patients with KFLC-index>100 (n=31), 11 subjects (35.5%) showed reduced SDMT scores by ≥8 points at follow-up (mean follow-up time 7.3 ± 2.6 years), compared with their baseline scores (p=0.01). Baseline KFLC-index>100 was strongly associated with a higher hazard of SDMT score reduction at follow-up (adjusted hazard ratio 10.5, 95% confidence interval 2.2-50.8, p=0.003; median time to SDMT reduction 7 years).

Conclusion

Intrathecal KFLC synthesis has become an attractive diagnostic tool for MS. We show for the first time that in a real-world setting of early RRMS, KFLC-index predicted cognitive decline. Whether this predictive ability of KFLC-index also concerns other cognitive domains than IPS, warrants further investigations.

Neural stem cell transplantation in patients with progressive multiple sclerosis: an open-label, phase 1 study

Innovative pro-regenerative treatment strategies for progressive multiple sclerosis (PMS), combining neuroprotection and immunomodulation, represent an unmet need. Neural precursor cells (NPCs) transplanted in animal models of multiple sclerosis have shown preclinical efficacy by promoting neuroprotection and remyelination by releasing molecules sustaining trophic support and neural plasticity. Here we present the results of STEMS, a prospective, therapeutic exploratory, non-randomized, open-label, single-dose-finding phase 1 clinical trial ( NCT03269071 , EudraCT 2016-002020-86), performed at San Raffaele Hospital in Milan, Italy, evaluating the feasibility, safety and tolerability of intrathecally transplanted human fetal NPCs (hfNPCs) in 12 patients with PMS (with evidence of disease progression, Expanded Disability Status Scale ≥6.5, age 18-55 years, disease duration 2-20 years, without any alternative approved therapy). The safety primary outcome was reached, with no severe adverse reactions related to hfNPCs at 2-year follow-up, clearly demonstrating that hfNPC therapy in PMS is feasible, safe and tolerable. Exploratory secondary analyses showed a lower rate of brain atrophy in patients receiving the highest dosage of hfNPCs and increased cerebrospinal fluid levels of anti-inflammatory and neuroprotective molecules. Although preliminary, these results support the rationale and value of future clinical studies with the highest dose of hfNPCs in a larger cohort of patients.

Factors associated with material deprivation in persons with multiple sclerosis in Switzerland: Cross-sectional data from the Swiss Multiple Sclerosis Registry

BACKGROUND

Multiple sclerosis (MS) impacts education, future career pathways and working capability and therefore may negatively impact the financial situation of persons with MS (pwMS) in Switzerland. We therefore investigated the financial situation and its influencing sociodemographic and disease-specific factors of pwMS compared to the general Swiss population with focus on material deprivation (MD).

METHODS

Data on the financial situation of pwMS were collected via a specific questionnaire added to the regular, semi-annual follow-up assessments of the Swiss Multiple Sclerosis Registry. Questions were taken in an unmodified format from the standardized "Statistics on Income and Living Conditions" (SILC) questionnaire 2019 of the Federal Statistical Office of Switzerland which evaluates the financial situation of the general Swiss population, enabling a direct comparison of pwMS with the general Swiss population.

RESULTS

PwMS were 1.5 times more frequently affected by MD than the general Swiss population (6.3% of pwMS versus 4.2% of the general Swiss population) which was confirmed in a multivariable logistic regression analysis of pooled SILC and Swiss Multiple Sclerosis Registry (SMSR) data. High symptom burden, having only mandatory schooling, well as having a pending disability insurance application (as opposed to no application or receiving benefits) were associated with a higher odds of MD whereas higher education, older age, having a Swiss citizenship, living with a spouse or a partner or being currently employed were independently associated with a lower odds of MD.

CONCLUSION

MS has a negative impact on the financial situation and is associated with MD. PwMS with a high symptom burden at the transition from work force to receiving disability benefits appeared to be vulnerable for MD. Higher education, older age, having a Swiss citizenship, living with a spouse or a partner or being currently employed were independently associated with a lower odds of MD.

Cognitive rehabilitation in multiple sclerosis: Three digital ingredients to address current and future priorities

Multiple sclerosis (MS) is a neurological chronic disease with autoimmune demyelinating lesions and one of the most common disability causes in young adults. People with MS (PwMS) experience cognitive impairments (CIs) and clinical evidence shows their presence during all MS stages even in the absence of other symptoms. Cognitive rehabilitation (CR) aims at reducing CI and improving PwMS' awareness of cognitive difficulties faced in their daily living. More defined cognitive profiles, easier treatment access and the need to transfer intervention effects into everyday life activities are aims of utmost relevance for CR in MS. Currently, advanced technologies may pave the way to rethink CR in MS to address the priority of more personalized and effective, accessible and ecological interventions. For this purpose, digital twins, tele-cognitive-rehabilitation and metaverse are the main candidate digital ingredients. Based on scientific evidences, we propose digital twin technology to enhance MS cognitive phenotyping; tele-cognitive-rehabilitation to make feasible the cognitive intervention access to a larger number of PwMS; and metaverse to represent the best choice to train real-world dual- and multi-tasking deficits in virtual daily life environments. Moreover, multi-domain high-frequency big-data collected through tele-cognitive-assessment, tele-cognitive-rehabilitation, and metaverse may be merged to refine artificial intelligence algorithms and obtain increasingly detailed patient's cognitive profile in order to enhance intervention personalization. Here, we present how these digital ingredients and their integration could be crucial to address the current and future needs of CR facilitating the early detection of subtle CI and the delivery of increasingly effective treatments.

Association of spinal cord lesions with cognition in multiple sclerosis

Purpose: The effect of spinal cord involvement, which is closely related to physical disability and prognosis, on cognitive functions in multiple sclerosis. Materials and Methods: Twenty nine MS patients (2 clinically isolated syndrome, 23 relapsing and remitting MS, 2 secondary progressive MS, 2 primary progressive MS) were included in the study. Demographic characteristics, expanded disability status scale (EDSS) score, cognition assessed by brief repeatable battery of neuropsychological tests, brain and spinal cord T2 lesion number were evaluated. Results: Older age, later age of disease onset, education duration are the features affecting cognitive test results. Brain and spinal cord lesion numbers did not have any effect on cognitive tests. Patients with spinal cord lesions had higher EDSS compared to patients without, however there was no difference regarding cognitive test results between groups. Conclusion: Spinal cord lesions are associated with physical disability quantified by EDSS. Longitudinal studies with larger samples are needed to investigate the effect of presence and number of cord lesions as well as cervical cord atrophy on cognitive test results.

Cognitive Relapse in Multiple Sclerosis: New Findings and Directions for Future Research

Multiple sclerosis (MS) is a chronic inflammatory, demyelinating disease of the central nervous system, often presenting with brain atrophy and cognitive impairment (CI). In the relapsing–remitting phenotype, cognitive performance is increasingly recognized to decline acutely during MS relapse, with varying degrees of recovery afterwards. Therefore, CI in MS may result from incomplete recovery from episodes of so-called “cognitive relapse”, gradual neurodegeneration, or both. Among a variety of validated measures of cognitive performance, the Symbol Digit Modalities Test (SDMT) represents the most sensitive measure of cognitive decline and is easily translated to clinical practice. In fact, cognitive relapse identified using the SDMT has been reported in clinically relapsing cohorts as well as in individuals with no other neurological signs, suggesting that routine cognitive assessment may be necessary to fully appreciate the extent of a patient’s disease activity. The aim of this narrative review is as follows: (1) to provide the historical context for neuropsychological assessment in MS, (2) to provide a summation of key studies describing the cognitive relapse phenomenon, and (3) to discuss current gaps in our knowledge and highlight avenues for future research.

Validation of cognitive screening questionnaire for neurological disorders (CSQND) for screening of cognitive complaints among patients with multiple sclerosis

Background

The prevalence of cognitive impairment (CI) can reach up to 65% among multiple sclerosis (MS) patients. Self-administered screening questionnaires can offer a valuable solution for screening MS patients for cognitive complaints. The cognitive screening questionnaire for neurological disorders (CSQND) is an Arabic self-administered questionnaire that has been developed to screen patients with various neurological disorders attending neurology clinics. The aim of this study was to assess cognitive complaints and to validate the CSQND as a screening tool among Egyptian MS patients.

Results

Four-hundred MS patients and 400 controls were included in this study. All 400 patients and 400 controls were subjected to the CSQND, only 50 out of the 400 patients and 50 out of the 400 controls retook the CSQND 1 week later to establish test–retest reliability. Fifty patients and 50 controls were assessed by the symbol digit modalities test (SDMT) to establish concurrent validity. Thirty-four percent of patients complained of memory problems, 51% complained of concentration difficulties, 34% complained of language difficulties and 22.5% complained of space and time disorientation. Multiple sclerosis patients had significantly more cognitive complaints (12.4 ± 12.6) compared to controls (6.2 ± 6.8) when screened using the CSQND (P < 0.000001). Total scores of CSQND were positively significantly correlated to age at onset, total disease duration, EDSS scores and total number of relapses, (r = 0.14; 0.275; 0.3; 0.167, respectively), P < 0.05 for all. Agreement was found between CSQND results and the SDMT results, where the line of equality lied within the 95% confidence interval of the mean. A significant positive correlation was found between the CSQND results at the first application and upon retesting both in patients (R = 0.9, P = 0.0001) and controls (R = 0.85, P = 0.0001).

Conclusions

The CSQND was found to be a simple, valid, and reliable self-administered questionnaire to screen for cognitive complaints in MS patients.

Improved prediction of early cognitive impairment in multiple sclerosis combining blood and imaging biomarkers

Disability in multiple sclerosis is generally classified by sensory and motor symptoms, yet cognitive impairment has been identified as a frequent manifestation already in the early disease stages. Imaging- and more recently blood-based biomarkers have become increasingly important for understanding cognitive decline associated with multiple sclerosis. Thus, we sought to determine the prognostic utility of serum neurofilament light chain levels alone and in combination with MRI markers by examining their ability to predict cognitive impairment in early multiple sclerosis. A comprehensive and detailed assessment of 152 early multiple sclerosis patients (Expanded Disability Status Scale: 1.3 ± 1.2, mean age: 33.0 ± 10.0 years) was performed, which included serum neurofilament light chain measurement, MRI markers (i.e. T₂-hyperintense lesion volume and grey matter volume) acquisition and completion of a set of cognitive tests (Symbol Digits Modalities Test, Paced Auditory Serial Addition Test, Verbal Learning and Memory Test) and mood questionnaires (Hospital Anxiety and Depression scale, Fatigue Scale for Motor and Cognitive Functions). Support vector regression, a branch of unsupervised machine learning, was applied to test serum neurofilament light chain and combination models of biomarkers for the prediction of neuropsychological test performance. The support vector regression results were validated in a replication cohort of 101 early multiple sclerosis patients (Expanded Disability Status Scale: 1.1 ± 1.2, mean age: 34.4 ± 10.6 years). Higher serum neurofilament light chain levels were associated with worse Symbol Digits Modalities Test scores after adjusting for age, sex Expanded Disability Status Scale, disease duration and disease-modifying therapy (B = −0.561; SE = 0.192; P = 0.004; 95% CI = −0.940 to −0.182). Besides this association, serum neurofilament light chain levels were not linked to any other cognitive or mood measures (all P-values > 0.05). The tripartite combination of serum neurofilament light chain levels, lesion volume and grey matter volume showed a cross-validated accuracy of 88.7% (90.8% in the replication cohort) in predicting Symbol Digits Modalities Test performance in the support vector regression approach, and outperformed each single biomarker (accuracy range: 68.6–75.6% and 68.9–77.8% in the replication cohort), as well as the dual biomarker combinations (accuracy range: 71.8–82.3% and 72.6–85.6% in the replication cohort). Taken together, early neuro-axonal loss reflects worse information processing speed, the key deficit underlying cognitive dysfunction in multiple sclerosis. Our findings demonstrate that combining blood and imaging measures improves the accuracy of predicting cognitive impairment, highlighting the clinical utility of cross-modal biomarkers in multiple sclerosis.

Neural Processes of Psychological Stress and Relaxation Predict the Future Evolution of Quality of Life in Multiple Sclerosis

Health-related quality of life (HRQoL) is an essential complementary parameter in the assessment of disease burden and treatment outcome in multiple sclerosis (MS) and can be affected by neuropsychiatric symptoms, which in turn are sensitive to psychological stress. However, until now, the impact of neurobiological stress and relaxation on HRQoL in MS has not been investigated. We thus evaluated whether the activity of neural networks triggered by mild psychological stress (elicited in an fMRI task comprising mental arithmetic with feedback) or by stress termination (i.e., relaxation) at baseline (T0) predicts HRQoL variations occurring between T0 and a follow-up visit (T1) in 28 patients using a robust regression and permutation testing. The median delay between T0 and T1 was 902 (range: 363–1,169) days. We assessed HRQoL based on the Hamburg Quality of Life Questionnaire in MS (HAQUAMS) and accounted for the impact of established HRQoL predictors and the cognitive performance of the participants. Relaxation-triggered activity of a widespread neural network predicted future variations in overall HRQoL (t = 3.68, p_{family−wise error [FWE]}-corrected = 0.008). Complementary analyses showed that relaxation-triggered activity of the same network at baseline was associated with variations in the HAQUAMS mood subscale on an α_FWE = 0.1 level (t = 3.37, p_FWE = 0.087). Finally, stress-induced activity of a prefronto-limbic network predicted future variations in the HAQUAMS lower limb mobility subscale (t = −3.62, p_FWE = 0.020). Functional neural network measures of psychological stress and relaxation contain prognostic information for future HRQoL evolution in MS independent of clinical predictors.

Factors Influencing the Degree of Disability in Patients With Multiple Sclerosis

Objective: To explore the factors influencing the degree of disability in patients with multiple sclerosis (MS), and to provide evidence for its early diagnosis, prognostic evaluation and clinical intervention.

Methods: This retrospective observational study included 72 patients with relapsing-remitting multiple sclerosis (RRMS) at the First Hospital of Shanxi Medical University. All patients completed craniocerebral and spinal cord MRI (with or without Gd enhancement) and were evaluated for Expanded Disability Status Score (EDSS) scores before receiving treatment.

Results: Among 72 patients with RRMS, 45 (62.5%) had an EDSS score ≤3; A total of 27 patients (37.5%) had an EDSS score >3 points. Univariate analysis showed that age, annual recurrence rate (ARR), drug use, albumin (ALB), triglycerides (TG), and total number of lesions in groups with EDSS score ≤3 were significantly different from those with an EDSS score > 3 points (P < 0.05). Multivariate logistic regression analysis showed that ALB, total number of lesions, and drug use were independent influencing factors of the degree of disability in patients with MS, and the difference was statistically significant (P < 0.05). An ROC curve was constructed using ALB and the total number of lesions. The AUC of ALB was 0.681, P < 0.05, and the best cut-off value was 44.2 g/L. Its sensitivity to predict the degree of disability in patients with multiple sclerosis was 85.2%, while its specificity was 51.1%. The AUC of the total number of lesions was 0.665 (P < 0.05) and the best cut-off value was 5.5. Its sensitivity to predict the degree of disability in patients with multiple sclerosis was 70.4%, while its specificity was 64.4%. The AUC of the combined ALB, total number of lesions, and drug use was 0.795 (P < 0.05), sensitivity was 77.8, and specificity was 73.3%. The optimal diagnostic cut-off value of the regression equation for the EDSS score of patients with multiple sclerosis was 0.420.

Conclusion: Serum ALB, total number of lesions, and drug use in patients with multiple sclerosis were independent factors influencing the degree of disability. These findings provide clinical evidence for the prognostic evaluation and early intervention of patients with multiple sclerosis.

Associations between socioemotional alterations, quality of life, and social functioning in multiple sclerosis: A scoping review

The main aim of the present scoping review is to systematically review the available studies that investigated the associations between socioemotional alterations (i.e., social cognition impairments/alexithymia/difficulties in emotion regulation) and both reduced QoL and social functioning in patients with Multiple Sclerosis (MS). The articles were selected from the PubMed, PsycINFO, and Scopus databases. The main exclusion criteria were qualitative studies, articles that did not use validated instruments, and studies that did not investigate the association between socioemotional skills and QoL/social functioning in MS. Of the eight studies fulfilling the inclusion criteria, six found significant associations between social cognitive and emotion regulation abilities and QoL/social functioning in patients with MS, while two found no significant relationships particularly between the performance on social cognition tasks and QoL measures. Overall, the majority of findings seem to highlight that socioemotional alterations contribute to impaired QoL and social functioning in MS. However, given the still limited evidence, future studies are needed to replicate and confirm the available results, paying attention to two principal aspects: the use of standardized and ecological tasks for the assessment of social cognition skills and the recruitment of samples involving patients with different types of MS.

Examining the Clinical Utility of Selected Memory-Based Embedded Performance Validity Tests in Neuropsychological Assessment of Patients with Multiple Sclerosis

Within the neuropsychological assessment, clinicians are responsible for ensuring the validity of obtained cognitive data. As such, increased attention is being paid to performance validity in patients with multiple sclerosis (pwMS). Experts have proposed batteries of neuropsychological tests for use in this population, though none contain recommendations for standalone performance validity tests (PVTs). The California Verbal Learning Test, Second Edition (CVLT-II) and Brief Visuospatial Memory Test, Revised (BVMT-R)—both of which are included in the aforementioned recommended neuropsychological batteries—include previously validated embedded PVTs (which offer some advantages, including expedience and reduced costs), with no prior work exploring their utility in pwMS. The purpose of the present study was to determine the potential clinical utility of embedded PVTs to detect the signal of non-credibility as operationally defined by below criterion standalone PVT performance. One hundred thirty-three (133) patients (M age = 48.28; 76.7% women; 85.0% White) with MS were referred for neuropsychological assessment at a large, Midwestern academic medical center. Patients were placed into “credible” (n = 100) or “noncredible” (n = 33) groups based on a standalone PVT criterion. Classification statistics for four CVLT-II and BVMT-R PVTs of interest in isolation were poor (AUCs = 0.58–0.62). Several arithmetic and logistic regression-derived multivariate formulas were calculated, all of which similarly demonstrated poor discriminability (AUCs = 0.61–0.64). Although embedded PVTs may arguably maximize efficiency and minimize test burden in pwMS, common ones in the CVLT-II and BVMT-R may not be psychometrically appropriate, sufficiently sensitive, nor substitutable for standalone PVTs in this population. Clinical neuropsychologists who evaluate such patients are encouraged to include standalone PVTs in their assessment batteries to ensure that clinical care conclusions drawn from neuropsychological data are valid.

Understanding visual-spatial perceptual deficits in individuals with multiple sclerosis: an analysis of patient performance on the Hooper Visual Organization Test and Visual Form Discrimination

Purpose: Although the cognitive sequelae of multiple sclerosis have been recognized for more than four decades, the focus of research has been on studying the more common deficits of the disease, including those involving memory and information processing speed. Less understood and investigated are the visual-spatial perceptual disturbances of multiple sclerosis, which can be difficult to assess and interpret given the potential confounds associated with the physical problems and other cognitive disturbances of the disorder.Materials and methods: This study examined the visual-spatial perceptual deficits of multiple sclerosis in 40 participants diagnosed with this condition using two measures generally unaffected by the aforementioned confounds, the Hooper Visual Organization Test and Visual Form Discrimination.Results: Results revealed both measures to be sensitive to the impairments of multiple sclerosis but suggested that they are assessing somewhat different aspects of visual-spatial perception in this population, given their relationship with one another and with disease-related variables.Conclusions: In this light, findings indicate that a complete and accurate understanding of the visual-spatial perceptual sequelae of multiple sclerosis requires the administration of more than a single measure.

Structural and Functional Connectivity Substrates of Cognitive Impairment in Multiple Sclerosis

Cognitive impairment (CI) occurs in 43 to 70% of multiple sclerosis (MS) patients at both early and later disease stages. Cognitive domains typically involved in MS include attention, information processing speed, memory, and executive control. The growing use of advanced magnetic resonance imaging (MRI) techniques is furthering our understanding on the altered structural connectivity (SC) and functional connectivity (FC) substrates of CI in MS. Regarding SC, different diffusion tensor imaging (DTI) measures (e.g., fractional anisotropy, diffusivities) along tractography-derived white matter (WM) tracts showed relevance toward CI. Novel diffusion MRI techniques, including diffusion kurtosis imaging, diffusion spectrum imaging, high angular resolution diffusion imaging, and neurite orientation dispersion and density imaging, showed more pathological specificity compared to the traditional DTI but require longer scan time and mathematical complexities for their interpretation. As for FC, task-based functional MRI (fMRI) has been traditionally used in MS to brain mapping the neural activity during various cognitive tasks. Analysis methods of resting fMRI (seed-based, independent component analysis, graph analysis) have been applied to uncover the functional substrates of CI in MS by revealing adaptive or maladaptive mechanisms of functional reorganization. The relevance for CI in MS of SC–FC relationships, reflecting common pathogenic mechanisms in WM and gray matter, has been recently explored by novel MRI analysis methods. This review summarizes recent advances on MRI techniques of SC and FC and their potential to provide a deeper understanding of the pathological substrates of CI in MS.

Strain and sex differences in somatosensation and sociability during experimental autoimmune encephalomyelitis

Multiple Sclerosis (MS) is an immune-mediated disease that results in major locomotor deficits. However, recent studies have revealed that fatigue, slow processing speed, and memory impairment are the top variables impacting employment status for MS patients. These suggest that cognitive effects may have a greater impact on productivity, lifestyle, and quality of life than do disease-related motor deficits. However, these debilitating non-locomotive effects have been largely overlooked in rodent models of the disease, such as experimental autoimmune encephalomyelitis (EAE). We hypothesized that murine EAE can also be used to assess non-locomotive dysfunctions (mood, sociability, muscle strength, and balance), as well as potential biases in these dysfunctions due to sex and/or strain. We actively immunized male and female C57BL/6 (B6) and SJL mice for EAE and evaluated their performance on the Deacon's weight grip test, Kondziela's inverted screen test, Hall's rope grip test, manual von Frey test for somatic nociception, and a three-chamber social preference paradigm. We hypothesized that EAE progression is associated with changes in muscle strength, balance, pain, and sociability and that these variations are linked to sex and/or strain. Our results indicate that strain but not sex influenced differences in muscle strength and balance during EAE, and both sex and strain have an impact on mechanical nociception, regardless of EAE disease status. Furthermore, both sex and strain had complex effects on differences in sociability. In conclusion, testing these additional modalities during EAE helps to unveil other signs and symptoms that could be used to determine the efficacy of a drug or treatment in the modulation of a MS-like behavior.

Characterization of alexithymia in clinically isolated syndrome

BACKGROUND

In multiple sclerosis (MS), the prevalence of alexithymia, defined as an inability to identify and describe emotions, is close to 50% but the prevalence of this symptom in clinically isolated syndrome (CIS) is unknown. Characterizing alexithymia at an early stage of the disease can help to clarify psychobehavioural disturbances in CIS patients.

METHODS

Forty CIS patients, who fulfilled the MRI criteria for dissemination in space, were matched with 40 healthy subjects. They completed self-assessment scales for alexithymia, depression, anxiety, apathy and empathy. Cognitive functions were assessed using a battery of neuropsychological tests.

RESULTS

The mean delay (± standard deviation) between the occurrence of CIS and inclusion in the study was 3.9 (2.8) months. The frequency of alexithymia was higher in CIS patients than in controls, with a prevalence of 42% (P<0.0001). Alexithymia correlated with anxiety and depression but not with cognition. Alexithymia was dependent only on depression (P=0.003).

CONCLUSION

Alexithymia, characterized by difficulty identifying feelings, is present in patients in the early stage of MS, and seems to be strongly associated with depression. Difficulty in social interaction could be a risk of future affective disorders.

Thalamic nuclei degeneration in multiple sclerosis

OBJECTIVES

To define both the severity and extent of structural alteration in certain thalamic nuclei by means of MR morphometry and to compare these findings with clinical performance in different phenotypes of multiple sclerosis (MS).

METHODS

We comparatively measured the thalamus nuclei volumes of patients with remitting-relapsing (RRMS) and secondary-progressive (SPMS) phenotypes of multiple sclerosis and healthy control subjects (HC). The evaluation of neurological performance was based on the results of Expanded Disability Status Scale and Multiple Sclerosis Severity Scale. Cognitive and mental state was rated according to the results of Mini-Mental State Examination, Frontal Assessment Battery, Montreal Cognitive Assessment and Symbol Digit Modalities Test. Freesurfer 6.0 was used for thalamic nuclei volumes calculation.

RESULTS

The median volume decline in thalamic pulvinar nuclei in RRMS group on the left side (anterior nucleus - 186,6 mm³, posterior nucleus - 149,4 mm³, medial nucleus 852,4 mm³) compared to HC (anterior nucleus - 229,2 mm³, posterior nucleus - 187,5 mm³, medical nucleus - 1081,3 mm³). Same group, right side - anterior nucleus - 219,5 mm³, posterior nucleus 187,1 mm³, medial nucleus - 989,6 mm³; HC group - anterior nucleus 261,1 mm³, posterior nucleus 240,5 mm³, medial nucleus - 1196,7 mm³ (p < 0,05). The highest correlation of the written section of SDMT was observed with the left ventral anterior nucleus (r = 0,71).

CONCLUSION

These findings indicate the credible correlation between clinical progression of neurological and cognitive impairment in MS patients with asymmetry left-sided thalamic nuclei atrophy and may be considered a potential predicting tool of MS progression.

MRI correlates of cognitive improvement after home-based EEG neurofeedback training in patients with multiple sclerosis: a pilot study

OBJECTIVE

Neurofeedback training may improve cognitive function in patients with neurological disorders. However, the underlying cerebral mechanisms of such improvements are poorly understood. Therefore, we aimed to investigate MRI correlates of cognitive improvement after EEG-based neurofeedback training in patients with MS (pwMS).

METHODS

Fourteen pwMS underwent ten neurofeedback training sessions within 3-4 weeks at home using a tele-rehabilitation system. Half of the pwMS (N = 7, responders) learned to self-regulate sensorimotor rhythm (SMR, 12-15 Hz) by visual feedback and improved cognitively after training, whereas the remainder (non-responders, n = 7) did not. Diffusion-tensor imaging and resting-state fMRI of the brain was performed before and after training. We analyzed fractional anisotropy (FA) and functional connectivity (FC) of the default-mode, sensorimotor (SMN) and salience network (SAL).

RESULTS

At baseline, responders and non-responders were comparable regarding sex, age, education, disease duration, physical and cognitive impairment, and MRI parameters. After training, compared to non-responders, responders showed increased FA and FC within the SAL and SMN. Cognitive improvement correlated with increased FC in SAL and a correlation trend with increased FA was observed.

CONCLUSIONS

This exploratory study suggests that successful neurofeedback training may not only lead to cognitive improvement, but also to increases in brain microstructure and functional connectivity.

Neuropsychiatric and Cognitive Sequelae of COVID-19

Coronavirus disease 2019 (COVID-19) is likely to have long-term mental health effects on individuals who have recovered from COVID-19. Rightly, there is a global response for recognition and planning on how to deal with mental health problems for everyone impacted by the global pandemic. This does not just include COVID-19 patients but the general public and health care workers as well. There is also a need to understand the role of the virus itself in the pathophysiology of mental health disorders and longer-term mental health sequelae. Emerging evidence suggests that COVID-19 patients develop neurological symptoms such as headache, altered consciousness, and paraesthesia. Brain tissue oedema and partial neurodegeneration have also been observed in an autopsy. In addition, there are reports that the virus has the potential to cause nervous system damage. Together, these findings point to a possible role of the virus in the development of acute psychiatric symptoms and long-term neuropsychiatric sequelae of COVID-19. The brain pathologies associated with COVID-19 infection is likely to have a long-term impact on cognitive processes. Evidence from other viral respiratory infections, such as severe acute respiratory syndrome (SARS), suggests a potential development of psychiatric disorders, long-term neuropsychiatric disorders, and cognitive problems. In this paper, we will review and evaluate the available evidence of acute and possible long-term neuropsychiatric manifestations of COVID-19. We will discuss possible pathophysiological mechanisms and the implications this will have on preparing a long-term strategy to monitor and manage such patients.

Early neuropsychological markers of cognitive involvement in multiple sclerosis

BACKGROUND

Cognitive impairment due to multiple sclerosis (MS) is common and often limits occupational functioning, contributes to disability, and reduces quality of life. Early detection of cognitive involvement in MS is critical for treatment planning and intervention, and frequent, regular cognitive monitoring may provide insight into subtle changes in disease progression.

OBJECTIVE

To compare the sensitivity and specificity of clinical, computer-based and experimental measures to early cognitive involvement in MS.

METHODS

Cognitive functioning was compared in MS participants early in the disease course to matched healthy controls using conventional, computer-based and functional assessments: the Brief International Cognitive Assessment in MS (BICAMS); the computer-based Cogstate Brief Battery (CBB); the Attention Network Test-Interaction (ANT-I), including intra-individual variability; and the Test of Everyday Cognitive Ability (TECA), a functional measure of instrumental activities of daily living.

RESULTS

MS participants (n = 25, mean disease duration= 5.82 ± 3.65 years) and demographically matched healthy controls (n = 29) completed the cognitive assessments. The Cogstate measure of choice reaction time (AUC = 0.73, p = .004), intra-individual variability on the ANT-I (AUC = 0.79, p = .001), and TECA (AUC = 0.78, p = .001) scores were the most sensitive and specific markers of cognitive involvement in MS.

CONCLUSIONS

Brief, repeatable, computer-based measures of reaction time and variability detect early MS associated cognitive involvement.

Cognitive impairment in multiple sclerosis: lessons from cerebrospinal fluid biomarkers

Cognitive impairment is a common clinical manifestation of multiple sclerosis, but its pathophysiology is not completely understood. White and grey matter injury together with synaptic dysfunction do play a role. The measurement of biomarkers in the cerebrospinal fluid and the study of their association with cognitive impairment may provide interesting in vivo evidence of the biological mechanisms underlying multiple sclerosis-related cognitive impairment. So far, only a few studies on this topic have been published, giving interesting results that deserve further investigation. Cerebrospinal fluid biomarkers of different pathophysiological mechanisms seem to reflect different neuropsychological patterns of cognitive deficits in multiple sclerosis. The aim of this review is to discuss the studies that have correlated cerebrospinal fluid markers of immune, glial and neuronal pathology with cognitive impairment in multiple sclerosis. Although preliminary, these findings suggest that cerebrospinal fluid biomarkers show some correlation with cognitive performance in multiple sclerosis, thus providing interesting insights into the mechanisms underlying the involvement of specific cognitive domains.

Cognitive Processing Speed Impairment Does Not Influence the Construct Validity of Six-Spot Step Test Performance in People With Multiple Sclerosis

OBJECTIVE

There is evidence supporting the construct validity of Six-Spot Step Test (SSST) performance as a functional mobility measure in people with multiple sclerosis (MS); however, it is unknown if cognitive processing speed impairment confounds the construct validity of SSST performance in MS, as this test seemingly requires intact cognitive processing. The objective of this study was to examine the influence of cognitive processing speed impairment on the construct validity and precision of SSST performance as a functional mobility measure in MS.

METHODS

Participants (N = 213) completed the SSST, timed 25-foot walk, 6-Minute Walk Test, Timed "Up and Go" Test, Multiple Sclerosis Walking Scale-12, device-measured steps per day, and Late-Life Function and Disability Inventory, Patient-Determined Disease Steps, and the Symbol-Digit Modalities Test as a cognitive processing speed measure. The overall sample was divided into subsamples with (n = 75) and without (n = 138) cognitive processing speed impairment based on normative Symbol-Digit Modalities Test data. Correlations between SSST performance with other mobility outcomes in the overall sample and cognitive processing speed impairment subsamples were examined and compared. SSST performance was compared relative to other mobility measures for differentiating MS walking function levels in people with and without cognitive processing speed impairment.

RESULTS

SSST performance was significantly and strongly correlated with most mobility outcomes in the overall sample and cognitive processing speed impairment subsamples. The magnitudes of correlations between SSST performance with most mobility outcomes were not statistically different among subsamples. Cognitive processing speed impairment did not diminish the relative precision of SSST performance for differentiating walking function levels.

CONCLUSION

The presence of cognitive processing speed impairment is not a source of invalidity or imprecision when interpreting SSST performance as a functional mobility measure among people with MS.

IMPACT

The SSST is a high-quality endpoint for inclusion in interventions targeting mobility in MS, regardless of cognitive processing speed status. This information is critical for rehabilitation research and clinical practice given that mobility and cognitive impairment are highly prevalent, co-occurring, and disabling in MS.

Siponimod and Cognition in Secondary Progressive Multiple Sclerosis: EXPAND Secondary Analyses

OBJECTIVE

To investigate the effects of siponimod on cognitive processing speed in patients with secondary progressive (SP) multiple sclerosis (MS), by means of a predefined exploratory and post hoc analysis of the Exploring the Efficacy and Safety of Siponimod in Patients With Secondary Progressive Multiple Sclerosis (EXPAND) study, a randomized controlled trial comparing siponimod and placebo.

METHODS

EXPAND was a double-blind, placebo-controlled phase 3 trial involving 1,651 patients with SPMS randomized (2:1) to either siponimod 2 mg/d or placebo. Cognitive function was assessed with the Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test (PASAT), and Brief Visuospatial Memory Test-Revised (BVMT-R) administered at baseline, 6-month intervals, and end of treatment.

RESULTS

Between-group differences in mean change from baseline in SDMT scores were significantly better in siponimod- vs placebo-treated patients at month 12 (difference 1.08 [95% confidence interval 0.23-1.94]; p = 0.0132), month 18 (1.23 [0.25-2.21); p = 0.0135), and month 24 (2.30 [1.11-3.50]; p = 0.0002). Siponimod-treated patients were at significantly lower risk for having a 4-point sustained decrease in SDMT score (hazard ratio [HR] 0.79 [0.65-0.96]; p = 0.0157), while their chance for having a 4-point sustained increase in SDMT score was higher (HR 1.28 [1.05-1.55]; p = 0.0131). PASAT and BVMT-R scores did not differ significantly between the 2 treatment groups (all p > 0.28).

CONCLUSION

Siponimod had a significant benefit on SDMT in patients with SPMS. Siponimod-treated patients were at significantly lower risk for having a ≥4-point decrease in SDMT score and had a significantly higher chance for having a ≥4-point increase in SDMT score, a magnitude of change accepted as clinically meaningful.

CLINICALTRIALSGOV IDENTIFIER

NCT01665144.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that, for patients with SPMS, siponimod had a significant benefit on cognitive processing speed.

Effect of Ozanimod on Symbol Digit Modalities Test Performance in Relapsing MS

BACKGROUND

Cognitive dysfunction, including slowed cognitive processing speed (CPS), is one of the most disabling symptoms of multiple sclerosis (MS). The Symbol Digit Modalities Test (SDMT) is a preferred measure of CPS for MS trials and routine screening. Based on encouraging SDMT results in the phase 3 SUNBEAM trial, these post hoc, exploratory analyses were conducted to further compare effects of the sphingosine 1-phosphate receptor modulator ozanimod versus intramuscular interferon β-1a on CPS in participants with relapsing multiple sclerosis (RMS).

METHODS

In the phase 3, double-blind, double-dummy, SUNBEAM study, adults (aged 18‒55 years) with RMS (N=1,346) were randomized to once-daily oral ozanimod 0.92 or 0.46 mg, or weekly intramuscular interferon β-1a 30 µg. The study continued until the last participant was treated for 12 months. CPS was measured as part of a secondary endpoint using the SDMT. Exploratory, post hoc analyses evaluated SDMT change and percentages of participants with clinically meaningful (≥4-point) SDMT improvement or worsening at months 6 and 12, and relationship between SDMT and brain volume on magnetic resonance imaging.

RESULTS

Ozanimod improved SDMT scores compared with interferon β-1a at months 6 and 12. At month 12, least squares mean difference in SDMT z-scores for ozanimod 0.92 mg versus interferon β-1a was 0.102 (95% CI, 0.031‒0.174, nominal p = 0.0051; standardized mean difference = 0.1376). A greater percentage of ozanimod 0.92 mg‒treated participants had clinically meaningful improvements in SDMT scores versus interferon β-1a at month 6 (30.0% versus 22.2%) and month 12 (35.6% versus 27.9%). Of those with SDMT improvement at month 6, 66.4% of those treated with ozanimod 0.92 mg and 55.9% of those treated with interferon β-1a had sustained improvement at month 12. Brain volume loss was similar for those with SDMT improvement versus worsening at month 12.

CONCLUSIONS

In these exploratory analyses, ozanimod had modestly beneficial effects on CPS in RMS participants. The effects of ozanimod on SDMT are being further evaluated in an ongoing 3-year clinical trial. SUNBEAM is registered on clinicaltrials.gov (NCT02294058) and the European Clinical Trials Database (EudraCT 2014-002320-27).

Cognitive impairment in multiple sclerosis: clinical management, MRI, and therapeutic avenues

Multiple sclerosis is a chronic, demyelinating disease of the CNS. Cognitive impairment is a sometimes neglected, yet common, sign and symptom with a profound effect on instrumental activities of daily living. The prevalence of cognitive impairment in multiple sclerosis varies across the lifespan and might be difficult to distinguish from other causes in older age. MRI studies show that widespread changes to brain networks contribute to cognitive dysfunction, and grey matter atrophy is an early sign of potential future cognitive decline. Neuropsychological research suggests that cognitive processing speed and episodic memory are the most frequently affected cognitive domains. Narrowing evaluation to these core areas permits brief, routine assessment in the clinical setting. Owing to its brevity, reliability, and sensitivity, the Symbol Digit Modalities Test, or its computer-based analogues, can be used to monitor episodes of acute disease activity. The Symbol Digit Modalities Test can also be used in clinical trials, and data increasingly show that cognitive processing speed and memory are amenable to cognitive training interventions.

The weak association between neurofilament levels at multiple sclerosis onset and cognitive performance after 9 years

BACKGROUND

Neurofilament light chain level in serum (sNfL) and cerebrospinal fluid (CSF-NfL) is a promising biomarker of disease activity in multiple sclerosis (MS). However, predictive value of neurofilaments for development of cognitive decline over long-term follow-up has not been extensively studied.

OBJECTIVE

To investigate the relationship between early neurofilament levels and cognitive performance after 9-years.

METHODS

We included 58 MS patients from the SET study. sNfL levels were measured at screening, at 1 and 2 years. CSF-NfL were measured in 36 patients at screening. Cognitive performance was assessed by the Brief International Cognitive Assessment for Multiple Sclerosis and the Paced Auditory Serial Addition Test-3 s at baseline, at 1, 2 and 9 years. Association between neurofilament levels and cognition was analyzed using Spearman´s correlation, logistic regression and mixed models.

RESULTS

We did not observe associations among early sNfL levels and cross-sectional or longitudinal cognitive measures, except of a trend for association between higher sNfL levels at screening and lower California Verbal Learning Test-II (CVLT-II) scores at year 1 (rho=-0.31, unadjusted p = 0.028). Higher sNfL level was not associated with increased risk of cognitive decline, except of a trend for greater risk of CVLT-II decrease in patients with higher sNfL levels at 1 year (OR=15.8; 95% CI=1.7-147.0; unadjusted p = 0.015). Similar trends were observed for CSF-NfL.

CONCLUSION

We found only weak association between sNfL levels at disease onset and evolution of cognitive performance over long-term follow-up.

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.

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.

Study protocol: improving cognition in people with progressive multiple sclerosis: a multi-arm, randomized, blinded, sham-controlled trial of cognitive rehabilitation and aerobic exercise (COGEx)

BACKGROUND

Cognitive dysfunction affects up to 70% of people with progressive MS (PMS). It can exert a deleterious effect on activities of daily living, employment and relationships. Preliminary evidence suggests that performance can improve with cognitive rehabilitation (CR) and aerobic exercise (EX), but existing data are predominantly from people with relapsing-remitting MS without cognitive impairment. There is therefore a need to investigate whether this is also the case in people with progressive forms of the disease who have objectively identified cognitive impairment. It is hypothesized that CR and EX are effective treatments for people with PMS who have cognitive impairment, in particular processing speed (PS) deficits, and that a combination of these two treatments is more effective than each individual treatment given alone. We further hypothesize that improvements in PS will be associated with modifications of functional and/or structural plasticity within specific brain networks/regions involved in PS measured with advanced MRI techniques.

METHODS

This study is a multisite, randomized, double-blinded, sham controlled clinical trial of CR and aerobic exercise. Three hundred and sixty subjects from 11 sites will be randomly assigned into one of four groups: CR plus aerobic exercise; CR plus sham exercise; CR sham plus aerobic exercise and CR sham plus sham exercise. Subjects will participate in the assigned treatments for 12 weeks, twice a week. All subjects will have a cognitive and physical assessment at baseline, 12 weeks and 24 weeks. In an embedded sub-study, approximately 30% of subjects will undergo structural and functional MRI to investigate the neural mechanisms underlying the behavioral response. The primary outcome is the Symbol Digit Modalities Test (SDMT) measuring PS. Secondary outcome measures include: indices of verbal and non-verbal memory, depression, walking speed and a dual cognitive-motor task and MRI.

DISCUSSION

The study is being undertaken in 6 countries (11 centres) in multiple languages (English, Italian, Danish, Dutch); with testing material validated and standardized in these languages. The rationale for this approach is to obtain a robustly powered sample size and to demonstrate that these two interventions can be given effectively in multiple countries and in different languages.

TRIAL REGISTRATION

The trial was registered on September 20th 2018 at www.clinicaltrials.gov having identifier NCT03679468. Registration was performed before recruitment was initiated.

The Cambridge Neuropsychological Test Automated Battery (CANTAB) Versus the Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) for the Assessment of Cognitive Function in Patients with Multiple Sclerosis

BACKGROUND

We determined how the Cambridge Neuropsychological Test Automated Battery (CANTAB) compared to the Minimal Assessment of Cognitive Function in multiple sclerosis (MACFIMS) in terms of sensitivity, specificity, and predictive values in detecting cognitive impairment in multiple sclerosis (MS) patients.

METHODS

Sixty MS patients were recruited, 2 of whom were lost to follow-up. On the first day of the neuropsychological examination, the standard MACFIMS battery and the day after, the CANTAB (paired-associate learning (PAL), reaction time (RTI), rapid visual information processing (RVP), and spatial working memory tasks (SWM)) were completed by the patients. The sensitivity, specificity, and predictive values of the CANTAB in the differentiation of cognitively impaired (CI) patients from not cognitively impaired (NCI) ones were compared with those of the MACFIMS battery using appropriate statistical tests.

RESULTS

Fifty-eight patients were categorized into two groups of CI (n=16 (27.58%)) and NCI (n=42 (72.41%)) based on the MACFIMS battery standard criteria. The best reporter indices and their cut-off scores for differentiation of CI from NCI patients in each task of the CANTAB were "total errors=13" for PAL, "between errors=26" for SWM, "five-choice reaction time=368.57" for RTI, and "mean latency=522.14" for RVP. The optimal cut-off point for distinguishing CI from NCI in the CANTAB was found to be an impaired function in 3 or more tasks [(AUC (95% CI): 0.97 (0.94-1.00); p<0.001)]. Accordingly, 36.20% of the patients were CI based on the CANTAB criteria. The inter-test agreement (CANTAB and MACFIMS batteries) was found to be the highest (Cohen's κ (95% CI): 0.80 (0.64-0.96)).

CONCLUSION

Results confirm that the CANTAB can discriminate CI from NCI MS patients with high accuracy, and its results are comparable to those of the MACFIMS battery; thus, they might be interchangeably used in the clinical practice.

Treatment and management of cognitive dysfunction in patients with multiple sclerosis

Cognitive impairment is a common and devastating manifestation of multiple sclerosis (MS). Although disease-modifying therapies have been efficacious for reducing relapse rates in MS, such treatments are ineffective for treating cognitive dysfunction. Alternative treatment approaches for mitigating cognitive problems are greatly needed in this population. To date, cognitive rehabilitation and exercise training have been identified as possible candidates for treating MS-related cognitive impairment; however, cognitive dysfunction is still often considered to be poorly managed in patients with MS. This Review provides a comprehensive overview of recent developments in the treatment and management of cognitive impairment in people with MS. We describe the theoretical rationales, current states of the science, field-wide challenges and recent advances in cognitive rehabilitation and exercise training for treating MS-related cognitive impairment. We also discuss future directions for research into the treatment of cognitive impairment in MS that should set the stage for the inclusion of cognitive rehabilitation and exercise training into clinical practice within the next decade.

Patient Attitudes to Routine Cognitive Testing in Multiple Sclerosis

BACKGROUND AND AIM

In recent years, cognitive dysfunction (CD) in multiple sclerosis (MS) has received increased attention. Neuropsychological tests have been developed allowing to monitor changes in patients' cognitive functions. Knowledge is lacking, however, about patients' attitudes towards introducing routine cognitive testing. It was the aim of this qualitative study to explore this.

MATERIALS AND METHODS

Based on a literature study, semi-structured interview guides were designed and used in qualitative interviews with 12 Danish patients. Participants were selected to represent different perspectives on CD and included patients with relapsing-remitting MS (RRMS) and secondary-progressive MS (SPMS), women and men with varying time since diagnosis and cognitive test scores using the Symbol Digit Modalities Test (SDMT). The data were analysed using a constructivist approach in order to identify significant relations between the quality of life (QoL) impact of CD, and attitudes towards routine cognitive testing.

RESULTS

Most participants reported several subtypes of CD, yet objective CD did not coincide with subjective CD nor did it translate directly into poorer QoL. Overall, CD appeared to have larger impact on the QoL of patients with RRMS and higher SDMT scores, compared to patients with SPMS and lower SDMT scores. The QoL impact of CD manifested itself in the encounter between individual symptoms, expectations, coping and meaningful activities. All patients supported an introduction of routine cognitive testing, but patients with RRMS and SPMS had different main reasons to do so. These were related to supporting research, optimising treatment decisions, and providing documentation of this invisible MS symptom.

CONCLUSION

All aspects of MS patients' QoL may be affected by CD. Introducing routine cognitive testing was widely supported by patients in all phases of MS calling for comprehensive care taking both physical and cognitive difficulties into account.

Brief international cognitive assessment for multiple sclerosis (BICAMS): A danish validation study of sensitivity in early stages of MS

BACKGROUND

Cognitive impairment is highly prevalent in multiple sclerosis (MS). Due to the lack of specialized neuropsychological resources in many MS clinics, a brief cognitive monitoring tool that can be administered by other MS clinic staff is needed. BICAMS (Brief International Cognitive As-sessment for Multiple Sclerosis) has been developed and recommended by MS experts to monitor MS-related cognitive impairment. International validations of the tool are warranted.

OBJECTIVE

The primary aim of the study was to establish a Danish translation of BICAMS as a feasible cognitive monitoring tool and to provide a Danish contribution to the international validation of BI-CAMS. A secondary aim was to determine if BICAMS correlated with self-reported cognition. The study population comprised people with MS (pwMS) with relatively early MS and newly diagnosed.

METHODS

65 pwMS were compared to healthy controls (HCs) matched on age, sex and education. PwMS and controls completed the BICAMS test battery which includes the Symbol Digit Modalities Test (SDMT, oral version), California Verbal Learning Test-II (CVLT-II) and the Brief Visuospatial Memory Test-Revised (BVMT-R). In addition, self-reported cognition, fatigue, depression and quality of life were assessed. To evaluate the reliability of the BICAMS test, all participants were retested 2-3 weeks later with alternate versions of the tests.

RESULTS

Mean age of the MS group was 37.2 years; 63% were female and all pwMS had a relapsing-remitting disease course. MS disease duration was relatively short; mean disease duration was 3.9 years and 32 of 65 pwMS (49%) were newly diagnosed with MS, i.e. diagnosed within the last 2 years. Mean EDSS was 1.8 with a span from 0-4. Comparison of the groups showed that the MS group performed significantly below the control group on the 3 BICAMS measures: SDMT (p<0.005), CVLT-II (p<0.05) and BVMT-R (p<0.05). When the results were controlled for influence from depression and fatigue by regression analysis, group differences were limited to the SDMT (p<0.05) and the BVMT-R (p<0.05) and these group differences were only found at the retest session. The BICAMS measures were reliable over time (r = 0.90 for SDMT, r = 0.82 for CVLT-II and r = 0.68 for BVMT-R). 32.3% of the MS population was cognitively impaired on at least one of the 3 BICAMS tests (defined as -1.5 SD compared to HCs). In the MS group 20% were impaired on the SDMT; 16.9% were impaired on the BVMT-R and 10.7% were impaired on the CVLT-II. There was no relationship between BICAMS test-scores and subjectively reported cognition, fatigue or depression.

CONCLUSION

The Danish translation of BICAMS was a reliable and feasible cognitive assessment tool. This finding was confirmed even in an MS population characterized by relatively early MS and high cognitive reserve. Frequency of cognitive dysfunction detected by BICAMS in this study was relatively low due to population characteristics.

No evidence of disease activity including cognition (NEDA-3 plus) in naïve pediatric multiple sclerosis patients treated with natalizumab

BACKGROUND

Pediatric-onset multiple sclerosis (POMS) is characterized by high inflammatory activity, aggressive course and early development of physical and cognitive disability. A highly effective early treatment must be considered in POMS.

OBJECTIVE

To evaluate safety and efficacy of natalizumab (NTZ) in naïve POMS.

METHODS

20 naïve POMS (13F, 7 M; mean age: 13.8 ± 2.7 years) were treated with NTZ for at least 24 months (mean number of infusions: 42 ± 20). No evidence of disease activity (NEDA)-3 plus status, i.e., no relapse, no disease progression (EDSS score), no radiological activity and no cognitive decline, was evaluated.

RESULTS

After 2 years of NTZ treatment, a significant reduction in the mean EDSS score (p < 0.0001) was observed in the whole cohort. During the follow-up, evidence of disease activity on MRI was observed in two patients (10%) and a mild decline in cognition was observed in other two. No patient had clinical relapse. At the time of last visit NEDA-3 plus status was maintained in 16 (80%) patients. No major adverse event was observed.

CONCLUSION

Early treatment of aggressive POMS with NTZ proved to be highly effective in achieving and maintaining the NEDA-3 plus status. Our data support the use of NTZ as first treatment choice in POMS.

Resolving the cognitive clinico-radiological paradox - Microstructural degeneration of fronto-striatal-thalamic loops in early active multiple sclerosis

BACKGROUND

Associations between cognitive impairment (CI) and both global and regional brain volumes can be weak in early multiple sclerosis (MS), a dilemma known as cognitive clinico-radiological paradox. We hypothesized that white-matter (WM) integrity within fronto-striatal-thalamic networks may be a sensitive marker for impaired performance in speed-dependent tasks, typical for early MS.

METHODS

Twenty-seven patients with early active relapsing-remitting MS (RRMS) received comprehensive neuropsychological assessment and underwent structural and diffusion-weighted brain magnetic resonance imaging (MRI). Global and regional brain volumes were obtained using FreeSurfer software. Fractional anisotropy (FA) was computed from diffusion tensor images to assess microstructural alterations within three anatomically predefined fronto-striatal-thalamic loops known to be relevant for speed-dependent attention and executive functions.

RESULTS

Overall cognitive performance (Spearman's ρ = .51) and performance in the domains processing speed (ρ = .44) and executive functions (ρ = .41) were correlated with patients' mean FA within the right dorsolateral-prefrontal loop. In addition, overall cognitive performance correlated with mean FA within the right lateral orbitofrontal loop (ρ = .39) - but only before controlling for WM lesion count. In contrast, regional volumes of grey-matter structures within these fronto-striatal-thalamic loops (including the thalamus) were not significantly related to CI. The total brain volume was associated with performance in the domain verbal memory (ρ = .43) only.

CONCLUSIONS

Microstructural degeneration within specific fronto-striatal-thalamic WM networks, previously characterized as crucial for task-monitoring, better accounts for speed-dependent CI in patients with early active RRMS than global or regional brain volumes. Our findings may advance our understanding of the neural substrates underlying CI characteristic for early RRMS.