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

Task- and resting-state fMRI studies in multiple sclerosis: From regions to systems and time-varying analysis. Current status and future perspective

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Functional MRI is able to detect adaptive and maladaptive abnormalities at different MS stages.

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Increased fMRI activity is a feature of early MS, while progressive exhaustion of adaptive mechanisms is detected later on in the disease.

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Collapse of long-range connections and impaired hub integration characterize MS network reorganization.

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Time-varying connectivity analysis provides useful and complementary pieces of information to static functional connectivity.

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New perspectives might be the use of multimodal MRI and artificial intelligence.

Multiple sclerosis (MS) is a neurological disorder affecting the central nervous system and features extensive functional brain changes that are poorly understood but relate strongly to clinical impairments. Functional magnetic resonance imaging (fMRI) is a non-invasive, powerful technique able to map activity of brain regions and to assess how such regions interact for an efficient brain network. FMRI has been widely applied to study functional brain changes in MS, allowing to investigate functional plasticity consequent to disease-related structural injury. The first studies in MS using active fMRI tasks mainly aimed to study such plastic changes by identifying abnormal activity in salient brain regions (or systems) involved by the task. In later studies the focus shifted towards resting state (RS) functional connectivity (FC) studies, which aimed to map large-scale functional networks of the brain and to establish how MS pathology impairs functional integration, eventually leading to the hypothesized network collapse as patients clinically progress. This review provides a summary of the main findings from studies using task-based and RS fMRI and illustrates how functional brain alterations relate to clinical disability and cognitive deficits in this condition. We also give an overview of longitudinal studies that used task-based and RS fMRI to monitor disease evolution and effects of motor and cognitive rehabilitation. In addition, we discuss the results of studies using newer technologies involving time-varying FC to investigate abnormal dynamism and flexibility of network configurations in MS. Finally, we show some preliminary results from two recent topics (i.e., multimodal MRI analysis and artificial intelligence) that are receiving increasing attention. Together, these functional studies could provide new (conceptual) insights into disease stage-specific mechanisms underlying progression in MS, with recommendations for future research.

Cognitive Decline in Older People with Multiple Sclerosis—A Narrative Review of the Literature

Several important questions regarding cognitive aging and dementia in older people with multiple sclerosis (PwMS) are the focus of this narrative review: Do older PwMS have worse cognitive decline compared to older people without MS? Can older PwMS develop dementia or other neurodegenerative diseases such as Alzheimer’s disease (AD) that may be accelerated due to MS? Are there any potential biomarkers that can help to determine the etiology of cognitive decline in older PwMS? What are the neural and cellular bases of cognitive aging and neurodegeneration in MS? Current evidence suggests that cognitive impairment in MS is distinguishable from that due to other neurodegenerative diseases, although older PwMS may present with accelerated cognitive decline. While dementia is prevalent in PwMS, there is currently no consensus on defining it. Cerebrospinal fluid and imaging biomarkers have the potential to identify disease processes linked to MS and other comorbidities—such as AD and vascular disease—in older PwMS, although more research is required. In conclusion, one should be aware that multiple underlying pathologies can coexist in older PwMS and cause cognitive decline. Future basic and clinical research will need to consider these complex factors to better understand the underlying pathophysiology, and to improve diagnostic accuracy.

Summary metrics of memory subnetwork functional connectivity alterations in multiple sclerosis

BACKGROUND

Memory dysfunction is common in multiple sclerosis (MS); mechanistic understanding of its causes is lacking. Large-scale network resting-state functional connectivity (RSFC) is sensitive to memory dysfunction.

OBJECTIVE

We derived and tested summary metrics of memory network RSFC.

METHODS

Cognitive data and 3T magnetic resonance imaging (MRI) scans were collected from 235 MS patients and 35 healthy controls (HCs). Index scores were calculated as RSFC within (anteriority index, AntI) and between (integration index, IntI) dorsomedial anterior temporal and medial temporal memory subnetworks. Group differences in index expression were evaluated. Associations between index scores and memory/non-memory cognition were evaluated; relationships between T2 lesion volume (T2LV) and index scores were assessed.

RESULTS

Index scores were related to memory and T2LV in MS patients, who showed marginally elevated AntI relative to HC (p = 0.06); no group differences were found for IntI. Better memory was associated with higher AntI (β = 0.15, p = 0.018) and IntI (β = 0.16, p = 0.014). No associations were found for non-memory cognition. Higher T2LV was associated with higher AntI and IntI; exploratory mediation analysis revealed significant inconsistent mediation, that is, higher index scores partially suppressed the negative association between T2LV and memory.

CONCLUSION

Summary, within-subject metrics permit replication and circumvent challenges of traditional (incommensurate) RSFC variables to advance development of mechanistic models of memory dysfunction in MS.

Progression in multiple sclerosis - a long-term problem

PURPOSE OF REVIEW

Disability progression in multiple sclerosis (MS) is strongly linked to central nervous system (CNS)-specific pathological processes that occur throughout all disease stages, but that become clinically evident in later phases of the disease. We here discuss current views and concepts for targeting progressive MS.

RECENT FINDINGS

Detailed clinical assessment of MS patients has identified an even closer entanglement of relapse-remitting and progressive disease, leading to novel concepts such as 'progression independent of relapse activity'. Evolving clinical concepts together with a focus on molecular (neurofilament light chain) and imaging (paramagnetic rim lesions) biomarkers might specifically identify patients at risk of developing progressive MS considerably earlier than before. A multitude of novel treatment approaches focus either on direct neuroaxonal protection or myelin regeneration or on beneficially modulating CNS-intrinsic or innate immune inflammation. Although some long-awaited trials have recently been unsuccessful, important lessons could still be drawn from novel trial designs providing frameworks for future clinical studies.

SUMMARY

Targeting progressive disease biology and repairing established damage is the current central challenge in the field of MS. Especially, the compartmentalized adaptive and innate CNS inflammation is an attractive target for novel approaches, probably as a combinatory approach together with neuroprotective or myelin regenerating strategies.

Interrogating large multiple sclerosis registries and databases: what information can be gained?

PURPOSE OF REVIEW

Although substantial progress has been made in understanding the natural history of multiple sclerosis (MS) and the development of new therapies, many questions concerning disease behavior and therapeutics remain to be answered. Data generated from real-world observational studies, based on large MS registries and databases and analyzed with advanced statistical methods, are offering the scientific community answers to some of these questions that are otherwise difficult or impossible to address. This review focuses on observational studies published in the last 2 years designed to compare the effectiveness of escalation vs. induction treatment strategies, to assess the effectiveness of treatment in pediatric-onset and late-onset MS, and to identify the clinical phenotype of secondary progressive (SP)MS.

RECENT FINDINGS

The main findings originating from real-world studies suggest that MS patients who will qualify for high-efficacy disease-modifying therapies (DMTs) should be offered these as early as possible to prevent irreversible accumulation of neurological disability. Especially pediatric patients derive substantial benefits from early treatment. In patients with late-onset MS, sustained exposure to DMTs may result in more favorable outcomes. Data-driven definitions are more accurate in defining transition to SPMS than diagnosis based solely on neurologists' judgment.

SUMMARY

Patients, physicians, industry, and policy-makers have all benefited from real-world evidence based on registry data, in answering questions of diagnostics, choice of treatment, and timing of treatment decisions.

Developing the Rationale for Including Virtual Reality in Cognitive Rehabilitation and Exercise Training Approaches for Managing Cognitive Dysfunction in MS

Cognitive impairment is a common and detrimental consequence of multiple sclerosis (MS) and current rehabilitation methods are insufficient. Cognitive rehabilitation (CR) and exercise training (ET) are the most promising behavioral approaches to mitigate cognitive deficits, but effects are small and do not effectively translate to improvements in everyday function. This article presents a conceptual framework supporting the use of virtual reality (VR) as an ideal, common adjuvant traditional CR and ET in MS. VR could strengthen the effects of CR and ET by increasing sensory input and promoting multisensory integration and processing during rehabilitation. For ET specifically, VR can also help incorporate components of CR into exercise sessions. In addition, VR can enhance the transfer of cognitive improvements to everyday functioning by providing a more ecologically valid training environment. There is a clear interest in adding VR to traditional rehabilitation techniques for neurological populations, a stronger body of evidence of this unique approach is needed in MS. Finally, to better understand how to best utilize VR in rehabilitation for cognitive deficits in MS, more systematic research is needed to better understand the mechanism(s) of action of VR with CR and ET.

The relationship between processing speed and verbal and non-verbal new learning and memory in progressive multiple sclerosis

Objective:

Processing speed (PS) deficits are the most common cognitive deficits in multiple sclerosis (MS), followed by learning and memory deficits, and are often an early cognitive problem. It has been argued that impaired PS is a primary consequence of MS, which in turn decreases learning. The current analysis examined the association between PS and learning in a large cohort of individuals with progressive MS.

Methods:

Baseline data from a randomized clinical trial on rehabilitation taking place at 11 centers across North America and Europe were analyzed. Participants included 275 individuals with clinically definite progressive MS (primary, secondary) consented into the trial.

Results:

Symbol Digit Modalities Test (SDMT) significantly correlated with California Verbal Learning Test-II (CVLT-II) ( r = 0.21, p = 0.0003) and Brief Visuospatial Memory Test–Revised (BVMT-R) ( r = 0.516, p < 0.0001). Receiver operating characteristic (ROC) analysis of the SDMT z score to distinguish between impaired and non-impaired CVLT-II performance demonstrated an area under the curve (AUC) of 0.61 (95% confidence interval (CI): 0.55–0.68) and a threshold of −1.62. ROC analysis between SDMT and BVMT-R resulted in an AUC of 0.77 (95% CI: 0.71–0.83) and threshold of −1.75 for the SDMT z score to predict impaired BVMT-R.

Conclusion:

Results indicate little ability beyond chance to predict CVLT-II from SDMT (61%), albeit statistically significant. In contrast, there was a 77% chance that the model could distinguish between impaired and non-impaired BVMT-R. Several potential explanations are discussed.

Predominant domains and associated demographic and clinical characteristics in multiple sclerosis-related cognitive impairment in mildly disabled patients

Background

Cognitive impairment (CI) is a common finding in multiple sclerosis (MS); however, there is a limited information about its prevalence in mildly disabled cases. We aimed to determine the most affected domains, and also the relation between the demographic factors and cognitive outcomes in mildly disabled relapsing–remitting MS (RRMS).

Results

Ninety-one mildly disabled RRMS patients with expanded disability status scale (EDSS) < 4 and literacy level above 9 years, were recruited. Based on Minimal Assessment of Cognitive Function in MS (MACFIMS) battery, CI was observed in 19.8% of the patients while 40.60% of the patients had at least one failure in cognitive tests. The most common impaired cognitive domain was information processing speed and working memory (27.5%). There was no significant difference between men and women in terms of CI in our sample (p-values > 0.05). Disease duration (p = 0.01), EDSS (p = 0.01), and education (p < 0.01) were significantly different between CI and non-CI patients, while age (p = 0.72), sex (p = 0.50), diagnostic gap (p = 0.89), and frequency of relapses (p = 0.22), did not differ considerably.

Conclusions

RRMS patients experience some degrees of CI that may present even before the onset of remarkable physical disability; nevertheless, a higher EDSS score and longer disease duration increases the risk of CI. These findings suggest routine cognitive assessment of MS patients.

miR-150-5p and let-7b-5p in Blood Myeloid Extracellular Vesicles Track Cognitive Symptoms in Patients with Multiple Sclerosis

Cognitive deficits strongly affect the quality of life of patients with multiple sclerosis (MS). However, no cognitive MS biomarkers are currently available. Extracellular vesicles (EVs) contain markers of parental cells and are able to pass from the brain into blood, representing a source of disease biomarkers. The aim of this study was to investigate whether small non-coding microRNAs (miRNAs) targeting synaptic genes and packaged in plasma EVs may reflect cognitive deficits in MS patients. Total EVs were precipitated by Exoquick from the plasma of twenty-six cognitively preserved (CP) and twenty-three cognitively impaired (CI) MS patients belonging to two independent cohorts. Myeloid EVs were extracted by affinity capture from total EVs using Isolectin B4 (IB4). Fourteen miRNAs targeting synaptic genes were selected and measured by RT-PCR in both total and myeloid EVs. Myeloid EVs from CI patients expressed higher levels of miR-150-5p and lower levels of let-7b-5p compared to CP patients. Stratification for progressive MS (PMS) and relapsing-remitting MS (RRMS) and correlation with clinical parameters suggested that these alterations might be attributable to cognitive deficits rather than disease progression. This study identifies miR-150-5p and let-7b-5p packaged in blood myeloid EVs as possible biomarkers for cognitive deficits in MS.

Effects and safety of exergaming in persons with multiple sclerosis during corticosteroid treatment: a pilot study

BACKGROUND

There is no information about the effects and usability of rehabilitation during corticosteroid treatment. This randomized clinical trial was conducted to evaluate and compare the effects and safety of exergaming and conventional rehabilitation (CR) on persons with multiple sclerosis (MS, pwMS) during corticosteroid treatment.

METHODS

The participants were randomly divided into two groups: Exergaming (n=15) and CR (n=15). Rehabilitation was applied by a physiotherapist who has expertise in MS. Measurements were done at baseline (T1), immediately after discharge (T2), and 1 month after discharge (T3). The outcome measures included upper extremity functions, walking, balance, cognitive functions, quality of life, depression, and fatigue.

RESULTS

The Nine Hole Peg Test, California Verbal Learning Test, Symbol Digit Modalities Test, MS Walking Scale-12, Six Spot Step Test showed a significant difference between T1 to T2 and T1 to T3 in the exergaming and CR groups (p < 0.05). The Timed 25 Foot Walk and Multiple Sclerosis International Quality of Life Questionnaire were significantly different between T1 to T3 in the exergaming and CR groups (p < 0.05). Brief Visuospatial Memory Test-Revised was significantly different between T1 to T3 and T2 to T3 in the exergaming and CR groups (p < 0.05). The MFIS showed a significant difference between T1 to T2 and T1 to T3 in the exergaming group (p < 0.05).

CONCLUSIONS

This study suggests that exergaming and CR are effective and safe methods for improving upper extremity, cognitive functions, fatigue, quality of life, balance, and walking ability in pwMS during the hospitalization period.

Long-term Cognitive Outcomes and Socioprofessional Attainment in People With Multiple Sclerosis With Childhood Onset

Background and Objectives

Patients with pediatric-onset multiple sclerosis (MS) can be especially vulnerable to cognitive impairment (CI) due to the onset of MS during a critical period for CNS development and maturation. The objective of this longitudinal study was to assess long-term cognitive functioning and socioprofessional attainment in the Italian pediatric MS cohort, previously assessed at baseline and 2 and 5 years.

Methods

The 48 patients evaluated at the 5-year assessment were screened for inclusion. All participants were assessed with a cognitive test battery exploring 4 different cognitive abilities. Depression, fatigue, and socioprofessional attainment were also assessed. Mean cognitive z scores were calculated for the whole cohort, and their evolution over time was analyzed with an analysis of variance for repeated measurements test. Predictors of cognitive worsening or improvement were assessed with a linear mixed-model analysis.

Results

Thirty-three participants were included (mean follow-up 12.8 ± 0.8 years). The global cognitive performance worsened at year 2 and improved at year 5, although the z score remained significantly lower than at baseline (−0.9 ± 1.2 vs −0.3 ± 0.9, p = 0.002). There was no significant variation between years 5 and 12 (−0.7 ± 1.1, p = 0.452). Higher IQ (>90) at baseline (effect 0.3, 95% CI 0.1–0.5, p = 0.017) and lower number of relapses in the 2 years before baseline (effect −0.1, 95% CI −0.1 to 0.1, p = 0.025) predicted better cognitive performances. Eighteen (54.5%) patients failed at least 2 tests compared with healthy controls and were defined as cognitively impaired. The presence of CI predicted worse socioprofessional attainment (β = 4.8, 95% CI 1.4–8.2, p = 0.008).

Discussion

The longitudinal cognitive trajectory in pediatric-onset MS has a heterogeneous course over time, with a decline in the first years followed by a partial recovery over the long term. However, at the last follow-up evaluation, the proportion of impaired patients was more than double compared with baseline, with a negative impact on the individual’s socioprofessional attainment in adulthood. This study underscores how cognitive reserve may partially mitigate the negative effects of brain damage, highlighting the critical importance of intellectual enrichment early during the disease course.

Neuropsychological Disability in the Case of Natalizumab-Related Progressive Multifocal Leukoencephalopathy

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) is a viral disease characterized by progressive damage or inflammation of the cerebral white matter that can be encountered in patients with multiple sclerosis (MS). There are cases of PML caused by pharmacological agents including natalizumab. Therefore, in patients treated with this drug, early identification of PML allows changes in the treatment plan, reducing the risks of morbidity and mortality.

CASE PRESENTATION

We reported the case of a 57-year-old female diagnosed with relapsing-remitting MS, who presented with PML related to natalizumab. The patient presented with change in behavioral, radiological abnormalities in the left parieto-temporal lobes. We described the longitudinal course of PML, from the diagnosis until the patient's death, documenting the progressive deterioration of her cognitive functioning, supported by changes on sequential brain scans and neurophysiological data.

CONCLUSION

The neuropsychological impairment documented in this case study expands the range of treatment-related complications associated with natalizumab, and provides evidence that occurrence of "atypical" cognitive deficits in MS may support the early diagnosis of PML.

The psychological benefits of neuropsychological assessment feedback as a psycho-educational therapeutic intervention: A randomized-controlled trial with cross-over in multiple sclerosis

ABSTRACTEvidence supporting the direct therapeutic benefits of neuropsychological assessment (NPA) feedback relies mostly upon post-feedback consumer surveys. This randomized-controlled trial with cross-over investigated the benefits of NPA feedback in multiple sclerosis (MS). Seventy-one participants were randomly allocated to NPA with feedback or a "delayed-treatment" control group. The primary hypotheses were that NPA feedback would lead to improved knowledge of cognitive functioning and improved coping. Outcome instruments were administered by a research assistant blinded to group allocation. At 1-week post-NPA feedback there were no significant group-by-time interaction effects, indicating no improvement. But nor was there any significant deterioration in psychological wellbeing, despite most participants receiving "bad news" confirming cognitive impairment. At 1-month follow-up, within-subjects' analyses not only found no evidence of any delayed deterioration, but showed clinically significant improvement (small-medium effects) in perceived everyday cognitive functioning, MS self-efficacy, stress and depression. Despite lack of improvement in the RCT component at 1-week post-NPA feedback, the absence of deterioration at this time, in addition to significant improvements in perceived cognitive functioning, self-efficacy and mood at follow-up, together with high satisfaction ratings, all support NPA feedback as a safe psycho-educational intervention that is followed by improved psychological wellbeing over time.Trial registration: Uniform Trial Number identifier: U1111-1127-1585.Trial registration: Australian New Zealand Clinical Trials Registry identifier: ACTRN12612000161820.

The Role of Tau beyond Alzheimer’s Disease: A Narrative Review

Nowadays, there is a need for reliable fluid biomarkers to improve differential diagnosis, prognosis, and the prediction of treatment response, particularly in the management of neurogenerative diseases that display an extreme variability in clinical phenotypes. In recent years, Tau protein has been progressively recognized as a valuable neuronal biomarker in several neurological conditions, not only Alzheimer’s disease (AD). Cerebrospinal fluid and serum Tau have been extensively investigated in several neurodegenerative disorders, from classically defined proteinopathy, e.g., amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), and Parkinson’s disease (PD), but also in inflammatory conditions such as multiple sclerosis (MS), as a marker of axonal damage. In MS, total Tau (t-Tau) may represent, along with other proteins, a marker with diagnostic and prognostic value. In ALS, t-Tau and, mainly, the phosphorylated-Tau/t-Tau ratio alone or integrated with transactive DNA binding protein of ~43 kDa (TDP-43), may represent a tool for both diagnosis and differential diagnosis of other motoneuron diseases or tauopathies. Evidence indicated the crucial role of the Tau protein in the pathogenesis of PD and other parkinsonian disorders. This narrative review summarizes current knowledge regarding non-AD neurodegenerative diseases and the Tau protein.

The Complex Interplay Between Trait Fatigue and Cognition in Multiple Sclerosis

Cognitive impairments are frequent in patients with Multiple Sclerosis (MS). Yet, the influence of MS-related symptoms on cognitive status is not clear. Studies investigating the impact of trait fatigue along with anxio-depressive symptoms on cognition are seldom, and even less considered fatigue as multidimensional. Moreover, these studies provided conflicting results.

Twenty-nine MS patients and 28 healthy controls, matched on age, gender and education underwent a full comprehensive neuropsychological assessment. Anxio-depressive and fatigue symptoms were assessed using the HAD scale and the MFIS, respectively. Six composite scores were derived from the neuropsychological assessment, reflecting the cognitive domains of working memory, verbal and visual learning, executive functions, attention and processing speed. Stepwise regression analyses were conducted in each group to investigate if trait cognitive and physical fatigue, depression and anxiety are relevant predictors of performance in each cognitive domain. In order to control for disease progression, patient’s EDSS score was also entered as predictor variable.

In the MS group, trait physical fatigue was the only significant predictor of working memory score. Cognitive fatigue was a predictor for executive functioning performance and for processing speed (as well as EDSS score for processing speed). In the healthy controls group, only an association between executive functioning and depression was observed.

Fatigue predicted cognition in MS patients only, beyond anxio-depressive symptoms and disease progression. Considering fatigue as a multidimensional symptom is paramount to better understand its association with cognition, as physical and cognitive fatigue are predictors of different cognitive processes.

Biochanin A Improves Memory Decline and Brain Pathology in Cuprizone-Induced Mouse Model of Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory and neurodegenerative disease of the central nervous system characterized by the demyelination of nerves, neural degeneration, and axonal loss. Cognitive impairment, including memory decline, is a significant feature in MS affecting up to 70% of patients. Thereby, it substantially impacts patients’ quality of life. Biochanin A (BCA) is an o-methylated isoflavone with a wide variety of pharmacological activities, including antioxidant, anti-inflammatory, and neuroprotective activities. Thus, this study aimed to investigate the possible protective effects of BCA on memory decline in the cuprizone (CPZ) model of MS. Thirty Swiss albino male mice (SWR/J) were randomly divided into three groups (n = 10): control (normal chow + i.p. 1:9 mixture of DMSO and PBS), CPZ (0.2% w/w of CPZ mixed into chow + i.p. 1:9 mixture of DMSO and PBS), and CPZ + BCA (0.2% w/w of CPZ mixed into chow + i.p. 40 mg/kg of BCA). At the last week of the study (week 5), a series of behavioral tasks were performed. A grip strength test was performed to assess muscle weakness while Y-maze, novel object recognition task (NORT), and novel arm discrimination task (NADT) were performed to assess memory. Additionally, histological examination of the hippocampus and the prefrontal cortex (PFC) were conducted. BCA administration caused a significant increase in the grip strength compared with the CPZ group. Additionally, BCA significantly improved the mice’s spatial memory in the Y-maze and recognition memory in the NORT and the NADT compared with the CPZ group. Moreover, BCA mitigated neuronal damage in the PFC and the hippocampus after five weeks of administration. In conclusion, our data demonstrates the possible protective effect of BCA against memory deterioration in mice fed with CPZ for five weeks.

Diagnosis of Alzheimer's disease and related dementia among people with multiple sclerosis: Large cohort study, USA

BACKGROUND

Alzheimer's disease and related dementia (ADRD) and multiple sclerosis (MS) are two neurodegenerative diseases with some shared pathophysiological characteristics. While the salient attribute of ADRD is a progressive decline in cognitive function, MS is mainly known for causing physical weakness, vision loss, and muscle stiffness. Progressive cognitive decline, however, is not uncommon among MS patients, and many case reports of MS were indicative of ADRD coexistence. Due to a lack of large epidemiological studies on this topic, we aimed to examine time to diagnosis of and adjusted hazard for ADRD using administrative claims data, comparing adults with and without MS.

METHODS

Using 2007-2017 private claims data from Optum Clinformatics Data Mart in the U.S., we identified adults (45+) with a MS diagnosis (n = 6151) as well as adults without MS for comparison (n = 916,143). We propensity score matched people with MS with those without (n = 6025) using age, sex, race/ethnicity, chronic conditions including cardiometabolic, psychologic, and musculoskeletal, U.S. Census Division, and socioeconomic variables. In addition to incidence estimates of ADRD diagnosis compared at 4-years, survival models were utilized to quantify unadjusted, fully adjusted, and adjusted propensity-matched hazard ratios.

RESULTS

Unmatched data revealed that incidence of early-onset ADRD diagnosis was 7 times higher among adults 45-64 years old with MS (1.4%) compared to those without (0.2%); among older adults (65+) with MS, incident ADRD was 4.0% compared to 3.3% among those without MS. Adjusted survival models indicated that adults with MS had a substantially high risk for early-onset ADRD diagnosis (among 45-64 years old: unmatched hazard ratio (HR): 4.25 (95% CI: 3.40 -5.32), matched HR: 4.49 (95% CI:2.62-7.69); among 65+ years old: unmatched HR: 1.39 (95% CI: 1.22, 1.58), matched HR: 1.26 (1.04, 1.54)).

CONCLUSIONS

Individuals with MS had a greater incidence of and risk for early- and late-onset ADRD diagnosis compared to those without MS. It is not clear whether this greater risk is due to an accelerated dementia risk or at least partially due to clinical misdiagnosis. Advancements in the development of clinical and imaging biomarkers should be more commonly used in clinical settings to facilitate future research on this topic.

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.

Thematic analysis of multiple sclerosis research by enhanced strategic diagram

Recent interest in multiple sclerosis research warrants literature analysis to evaluate the current state of the discipline and new research domains. This bibliometric review summarised the research trends and analysed research areas in multiple sclerosis over the last decade. The documents containing the term 'multiple sclerosis' in the article title were retrieved from the Scopus database. We used Harzing's Publish or Perish and VOSviewer for citation analysis and data visualisation, respectively. We found a total of 18,003 articles published in journals in the English language between 2012 and 2021. The emerging keywords identified utilising the enhanced strategic diagram were 'covid-19', 'teriflunomide', 'clinical trial', 'microglia', 'b cells', 'myelin', 'brain', 'white matter', 'functional connectivity', 'pain', 'employment', 'health-related quality of life', 'meta-analysis' and 'comorbidity'. This study demonstrates the tremendous growth of multiple sclerosis literature worldwide, which is expected to grow more than double during the next decade especially in the identified emerging topics.

The efficacy of speed of processing training for improving processing speed in individuals with multiple sclerosis: a randomized clinical trial

OBJECTIVE

The current study examines the efficacy of speed of processing training (SOPT) to improve processing speed (PS) in individuals with multiple sclerosis (MS). Outcomes included changes in the useful field of view (UFOV) and neuropsychological evaluation (NPE).

METHODS

This double-blind, placebo-controlled randomized clinical trial included 84 participants with clinically definite MS and impaired PS, 43 in the treatment group and 41 in the placebo control group. Participants completed a baseline NPE and a repeat NPE post-treatment. The treatment group was randomized to booster sessions or no contact. Long-term follow-up assessments were completed 6 months after treatment.

RESULTS

A significant effect of SOPT was observed on both the UFOV (large effect) and pattern comparison with a similar pattern of results noted on letter comparison, albeit at a trend level. The treatment effect was maintained 6 months later. The impact of booster sessions was not significant. Correlations between degree of improvement on the UFOV and the number of levels completed within each training task were significant for both speed and divided attention indicating that completion of more levels of training correlated with greater benefit.

CONCLUSION

SOPT is effective for treating PS deficits in MS with benefit documented on both the UFOV and a neuropsychological measure of PS. Less benefit was observed as the outcome measures became more distinct in cognitive demands from the treatment. Long-term maintenance was observed. The number of training levels completed within the 10-sessions exerted a significant impact on treatment benefit, with more levels completed resulting in greater benefit.

Telemedicine as a strategic intervention for cognitive rehabilitation in MS patients during COVID-19

The recent COVID-19 pandemic has taken the lives of nearly 5.2 million up to now. With no definite treatment and considering close contact as the primary mode of transmission, telemedicine has emerged as an essential medical care platform. Virtual medical communications have offered clinicians the opportunity to visit and follow up on patients more efficiently during the lockdown. Not only has telemedicine improved multiple sclerosis (MS) patients’ health and quality of life during the pandemic, but it could also be used as a cost-effective platform for physical and cognitive MS rehabilitation programs. Cognitive impairment is a common problem among MS patients even at the initial phases of the disease. Rehabilitation training programs such as RehaCom, BrainHQ, Speed of Processing Training (PST), and COGNI-TRAcK have made great strides in improving a wide range of cognitive functions that MS patients are challenged with. Regarding the impact of COVID-19 on the cognitive aspects of MS patients, efforts to implement rehabilitation training applications have been increased. Web-based mobile applications, virtual visits, and telephone follow-ups are examples of such efforts. Having said that, limitations such as privacy, socioeconomic disparities, e-health literacy, study settings, and challenges of neurologic examinationss have been raised. Since most MS patients are young, all the beneficiaries are encouraged to embrace the research in the field to pave the road for more feasible and efficient ways of cognitive enhancement in MS patients.

Effect of BDNF Val66Met polymorphism on hippocampal subfields in multiple sclerosis patients

Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism was shown to strongly affect BDNF function, but its role in modulating gray matter damage in multiple sclerosis (MS) patients is still not clear. Given BDNF relevance on the hippocampus, we aimed to explore BDNF Val66Met polymorphism effect on hippocampal subfield volumes and its role in cognitive functioning in MS patients. Using a 3T scanner, we obtained dual-echo and 3DT1-weighted sequences from 50 MS patients and 15 healthy controls (HC) consecutively enrolled. MS patients also underwent genotype analysis of BDNF, neurological and neuropsychological evaluation. Hippocampal subfields were segmented by using Freesurfer. The BDNF Val66Met polymorphism was found in 22 MS patients (44%). Compared to HC, MS patients had lower volume in: bilateral hippocampus-amygdala transition area (HATA); cornus ammonis (CA)1, granule cell layer of dentate gyrus (GCL-DG), CA4 and CA3 of the left hippocampal head; molecular layer (ML) of the left hippocampal body; presubiculum of right hippocampal body and right fimbria. Compared to BDNF Val66Val, Val66Met MS patients had higher volume in bilateral hippocampal tail; CA1, ML, CA3, CA4, and GCL-DG of left hippocampal head; CA1, ML, and CA3 of the left hippocampal body; left HATA and presubiculum of the right hippocampal head. In MS patients, higher lesion burden was associated with lower volume of presubiculum of right hippocampal body; lower volume of left hippocampal tail was associated with worse visuospatial memory performance; lower volume of left hippocampal head with worse performance in semantic fluency. Our findings suggest the BNDF Val66Met polymorphism may have a protective role in MS patients against both hippocampal atrophy and cognitive impairment. BDNF genotype might be a potential biomarker for predicting cognitive prognosis, and an interesting target to study for neuroprotective strategies.

Abnormal multisensory integration in relapsing–remitting multiple sclerosis

Temporal Binding Window (TBW) represents a reliable index of efficient multisensory integration process, which allows individuals to infer which sensory inputs from different modalities pertain to the same event. TBW alterations have been reported in some neurological and neuropsychiatric disorders and seem to negatively affects cognition and behavior. So far, it is still unknown whether deficits of multisensory integration, as indexed by an abnormal TBW, are present even in Multiple Sclerosis. We addressed this issue by testing 25 participants affected by relapsing–remitting Multiple Sclerosis (RRMS) and 30 age-matched healthy controls. Participants completed a simultaneity judgment task (SJ2) to assess the audio-visual TBW; two unimodal SJ2 versions were used as control tasks. Individuals with RRMS showed an enlarged audio-visual TBW (width range = from − 166 ms to + 198 ms), as compared to healthy controls (width range = − 177/ + 66 ms), thus showing an increased tendency to integrate temporally asynchronous visual and auditory stimuli. Instead, simultaneity perception of unimodal (visual or auditory) events overall did not differ from that of controls. These results provide first evidence of a selective deficit of multisensory integration in individuals affected by RRMS, besides the well-known motor and cognitive impairments. The reduced multisensory temporal acuity is likely caused by a disruption of the neural interplay between different sensory systems caused by multiple sclerosis.

Cerebrospinal fluid biomarkers and cognitive functions at multiple sclerosis diagnosis

Cognitive impairment (CI) is a frequent and disabling symptom in Multiple Sclerosis (MS). Axonal damage may contribute to CI development from early stages. Nevertheless, no biomarkers are at the moment available to track CI in MS patients. We aimed to explore the correlation of cerebrospinal fluid (CSF) axonal biomarkers, in particular: light-chain neurofilaments (NFL), Tau, and Beta-amyloid protein (Abeta) in MS patients with CI at the diagnosis. 62 newly diagnosed MS patients were enrolled, and cognition was evaluated using the Brief International Cognitive Assessment for MS (BICAMS) battery. CSF NFL, Abeta, and Tau levels were determined with commercial ELISA. Patients with CI (45.1%) did not differ for demographic, clinical, and MRI characteristics (except for lower educational level), but they displayed greater neurodegeneration, exhibiting higher mean CSF Tau protein (162.1 ± 52.96 pg/ml versus 132.2 ± 63.86 pg/ml p:0.03). No differences were observed for Abeta and NFL. The number of impaired tests and Tau were significantly correlated (r:0.32 p:0.01). Tau was higher in particular in patients with slowed information processing speed (IPS) (p:0.006) and a linear regression analysis accounting for EDSS, MRI, and MS subtype confirmed Tau as a weak predictor of IPS and cognitive impairment. In conclusion, CI has an important burden on the quality of life of MS patients and should be looked for even at diagnosis. Axonal damage biomarkers, and in particular Tau, seem to reflect cognition impairment in the early stages.

In-Depth Characterization of Somatic and Orofacial Sensitive Dysfunctions and Interfering-Symptoms in a Relapsing-Remitting Experimental Autoimmune Encephalomyelitis Mouse Model

Among the many symptoms (motor, sensory, and cognitive) associated with multiple sclerosis (MS), chronic pain is a common disabling condition. In particular, neuropathic pain symptoms are very prevalent and debilitating, even in early stages of the disease. Unfortunately, chronic pain still lacks efficient therapeutic agents. Progress is needed (i) clinically by better characterizing pain symptoms in MS and understanding the underlying mechanisms, and (ii) preclinically by developing a more closely dedicated model to identify new therapeutic targets and evaluate new drugs. In this setting, new variants of experimental autoimmune encephalomyelitis (EAE) are currently developed in mice to exhibit less severe motor impairments, thereby avoiding confounding factors in assessing pain behaviors over the disease course. Among these, the optimized relapsing-remitting EAE (QuilA-EAE) mouse model, induced using myelin oligodendrocyte glycoprotein peptide fragment (35–55), pertussis toxin, and quillaja bark saponin, seems very promising. Our study sought (i) to better define sensitive dysfunctions and (ii) to extend behavioral characterization to interfering symptoms often associated with pain during MS, such as mood disturbances, fatigue, and cognitive impairment, in this optimized QuilA-EAE model. We made an in-depth characterization of this optimized QuilA-EAE model, describing for the first time somatic thermal hyperalgesia associated with mechanical and cold allodynia. Evaluation of orofacial pain sensitivity showed no mechanical or thermal allodynia. Detailed evaluation of motor behaviors highlighted slight defects in fine motor coordination in the QuilA-EAE mice but without impact on pain evaluation. Finally, no anxiety-related or cognitive impairment was observed during the peak of sensitive symptoms. Pharmacologically, as previously described, we found that pregabalin, a treatment commonly used in neuropathic pain patients, induced an analgesic effect on mechanical allodynia. In addition, we showed an anti-hyperalgesic thermal effect on this model. Our results demonstrate that this QuilA-EAE model is clearly of interest for studying pain symptom development and so could be used to identify and evaluate new therapeutic targets. The presence of interfering symptoms still needs to be further characterized.

Myelination synchronizes cortical oscillations by consolidating parvalbumin-mediated phasic inhibition

Parvalbumin-positive (PV⁺) γ-aminobutyric acid (GABA) interneurons are critically involved in producing rapid network oscillations and cortical microcircuit computations, but the significance of PV⁺ axon myelination to the temporal features of inhibition remains elusive. Here, using toxic and genetic mouse models of demyelination and dysmyelination, respectively, we find that loss of compact myelin reduces PV⁺ interneuron presynaptic terminals and increases failures, and the weak phasic inhibition of pyramidal neurons abolishes optogenetically driven gamma oscillations in vivo. Strikingly, during behaviors of quiet wakefulness selectively theta rhythms are amplified and accompanied by highly synchronized interictal epileptic discharges. In support of a causal role of impaired PV-mediated inhibition, optogenetic activation of myelin-deficient PV⁺ interneurons attenuated the power of slow theta rhythms and limited interictal spike occurrence. Thus, myelination of PV axons is required to consolidate fast inhibition of pyramidal neurons and enable behavioral state-dependent modulation of local circuit synchronization.

Comparing diagnostic criteria for the diagnosis of neurocognitive disorders in multiple sclerosis

BACKGROUND

People with multiple sclerosis (MS) commonly experience cognitive impairment associated with the disease, but there is currently no agreed-upon operational definition for identifying the presence of that impairment, in either research or clinic contexts. The International MS Cognition Society (IMSCOGS) established a task force to begin to examine this issue and this paper represents the results of an initial pilot investigation. The aim of this paper was to compare two criterion sets to determine how to identify cognitive impairment among people with MS: the general Diagnostic and Statistical Manual (DSM-5) Criteria for neurocognitive disorders and criteria derived from existing MS research (scores in two domains fall 1.5 standard deviations below normative controls).

METHODS

Two hundred and ten people with MS presented for a brief cognitive evaluation in an MS Multidisciplinary Clinic at a midwestern academic medical center in the United States. Participants were generally middle aged (average 51.5 years), female (73.8%), and white (93.3%). McNemar's test was computed to compare the number of individuals whose cognitive test score performance was deemed cognitively normal, mildly impaired, or more significantly impaired.

RESULTS

DSM-5 criteria classified 87.2% of the sample as cognitively impaired, where 66.7% were more mildly impaired and 20.5% more significantly impaired. By contrast, research-based criteria classified 63.3% of the sample as cognitively impaired, with 49.5% as mildly impaired and 13.8% as more significantly impaired.

CONCLUSIONS

These findings indicate that compared to research criteria, the DSM-5 criteria classified far more people with MS as having cognitive impairment secondary to the disease. The paper discusses the potential benefits and drawbacks of the two diagnostic methods, highlighting that more work will be needed in order to establish a standardized and validated method for characterizing these impairments.

Reduction in cognitive processing speed surrounding multiple sclerosis relapse

Objective

The purpose of this study was to explore the longitudinal relationship between multiple sclerosis (MS) relapses and information processing efficiency among persons with relapsing–remitting MS.

Methods

We conducted a Swedish nationwide cohort study of persons with incident relapsing–remitting MS (2001–2019). Relapse information and symbol digit modalities test (SDMT) scores were obtained from the Swedish MS Registry. Follow‐up was categorized into 2 periods based on relapse status: “relapse” (90 days pre‐relapse to 730 days post‐relapse, subdivided into 10 periods) and “remission.” Linear mixed models compared SDMT scores during the relapse periods to SDMT scores recorded during remission (reference) with results reported as β‐coefficients and 95% confidence intervals (CIs), adjusted for age, sex, SDMT type (written vs oral), time‐varying, disease‐modifying therapy exposure and sequence of SDMT.

Results

Over a mean (SD) follow‐up of 10.7 (4.3) years, 31,529 distinct SDMTs were recorded among 3,877 persons with MS. There was a significant decline in information processing efficiency that lasted from 30 days pre‐relapse up to 550 days post‐relapse, with the largest decline occurring 0 to 30 days post‐relapse (β‐coefficient: −4.00 (95% CI = −4.61 to −3.39), relative to the period of remission.

Interpretation

We found evidence of cognitive change up to 1 month prior to relapse onset. The reduction in SDMT lasted 1.5 years and was clinically significant up to 3 months post‐relapse. These results suggest that the effects of a relapse on cognition are longer than previously thought and highlight the importance of reducing relapse rates as a potential means of preserving cognitive function. ANN NEUROL 2022;91:417–423

Remote self-administration of digital cognitive tests using the Brief Assessment of Cognition: Feasibility, reliability, and sensitivity to subjective cognitive decline

Cognitive impairment is a common and pervasive feature of etiologically diverse disorders of the central nervous system, and a target indication for a growing number of symptomatic and disease modifying drugs. Remotely acquired digital endpoints have been recognized for their potential in providing frequent, real-time monitoring of cognition, but their ultimate value will be determined by the reliability and sensitivity of measurement in the populations of interest. To this end, we describe initial validation of remote self-administration of cognitive tests within a regulatorily compliant tablet-based platform. Participants were 61 older adults (age 55+), including 20 individuals with subjective cognitive decline (SCD). To allow comparison between remote (in-home) and site-based testing, participants completed 2 testing sessions 1 week apart. Results for three of four cognitive domains assessed demonstrated equivalence between remote and site-based tests, with high cross-modality ICCs (absolute agreement) for Symbol Coding (ICC = 0.75), Visuospatial Working Memory (ICC = 0.70) and Verbal Fluency (ICC > 0.73). Group differences in these domains were significant and reflected sensitivity to objective cognitive impairment in the SCD group for both remote and site-based testing (p < 0.05). In contrast, performance on tests of verbal episodic memory suggested inflated performance during unmonitored testing and indicate reliable use of remote cognitive assessments may depend on the construct, as well as the population being tested.

Current status of neuroprotective and neuroregenerative strategies in multiple sclerosis: A systematic review

BACKGROUND

Immune-mediated demyelination and consequent degeneration of oligodendrocytes and axons are hallmark features of multiple sclerosis (MS). Remyelination declines in progressive MS, causing permanent axonal loss and irreversible disabilities. Strategies aimed at enhancing remyelination are critical to attenuate disease progression.

OBJECTIVE

We systematically reviewed recent advances in neuroprotective and regenerative therapies for MS, covering preclinical and clinical studies.

METHODS

We searched three biomedical databases using defined keywords. Two authors independently reviewed articles for inclusion based on pre-specified criteria. The data were extracted from each study and assessed for risk of bias.

RESULTS

Our search identified 7351 studies from 2014 to 2020, of which 221 met the defined criteria. These studies reported 262 interventions, wherein 92% were evaluated in animal models. These interventions comprised protein, RNA, lipid and cellular biologics, small molecules, inorganic compounds, and dietary and physiological interventions. Small molecules were the most highly represented strategy, followed by antibody therapies and stem cell transplantation.

CONCLUSION

While significant strides have been made to develop regenerative treatments for MS, the current evidence illustrates a skewed representation of the types of strategies that advance to clinical trials. Further examination is thus required to address current barriers to implementing experimental treatments in clinical settings.

Neuroimaging predictors of longitudinal disability and cognition outcomes in multiple sclerosis patients: A systematic review and meta-analysis

BACKGROUND

Cross-sectional magnetic resonance imaging (MRI) studies have generated substantial evidence relating neuroimaging abnormalities to clinical and cognitive decline in multiple sclerosis (MS). Longitudinal neuroimaging studies may have additional value for predicting future cognitive deficits or clinical impairment, potentially leading to earlier interventions and better disease management. We conducted a meta-analysis of longitudinal studies using neuroimaging to predict cognitive decline (i.e. the Symbol Digits Modalities Test, SDMT) and disability outcomes (i.e. the Expanded Disability Status Scale, EDSS) in MS.

METHODS

Our systematic literature search yielded 64 relevant publications encompassing 105 distinct sub-analyses. We performed a multilevel random-effects meta-analysis to estimate overall effect size for neuroimaging's ability to predict longitudinal cognitive and clinical decline, and a meta-regression to investigate the impact of distinct study factors on pooled effect size.

RESULTS

In the EDSS analyses, the meta-analysis yielded a medium overall pooled effect size (Pearson's correlation coefficient r = 0.42, 95% CI [0.37; 0.46]). The meta-regression further indicated that analyses exclusively evaluating gray matter tissue had significantly stronger effect sizes than analyses of white matter tissue or whole brain analyses (p < 0.05). No other study factors significantly influenced the pooled effect size (all p > 0.05). In the SDMT analyses, the meta-analysis yielded a medium overall pooled effect size (r = 0.47, 95% CI [0.32; 0.60]). The meta-regression found no significant study factors influencing the pooled effect size.

CONCLUSION

The present findings indicate that brain imaging is a medium predictor of longitudinal change in both disability progression (EDSS) and cognitive decline (SDMT). These findings reinforce the need for further longitudinal studies standardizing methods, using multimodal approaches, creating data consortiums, and publishing more complete datasets investigating MRI modalities to predict longitudinal disability and cognitive decline.

Myelin imaging measures as predictors of cognitive impairment in MS patients: A hybrid PET-MRI study

BACKGROUND

Cognitive impairment is one of the concerns of Multiple Sclerosis (MS) and has been related to myelin loss. Different neuroimaging methods have been used to quantify myelin and relate it to cognitive dysfunctions, among them Magnetization Transfer Ratio (MTR), Diffusion Tensor Imaging (DTI), and, more recently, Positron Emission Tomography (PET) with ¹¹C-PIB.

OBJECTIVE

To investigate different myelin imaging modalities as predictors of cognitive dysfunction.

METHODS

Fifty-one MS patients and 24 healthy controls underwent clinical and neuropsychological assessment and MTR, DTI (Axial Diffusion-AD and Fractional Anisotropy-FA maps), and ¹¹C-PIB PET images in a PET/MR hybrid system.

RESULTS

MTR and DTI(FA) differed in patients with or without cognitive impairment. There was an association of DTI(FA) and DTI(AD) with cognition and psychomotor speed for progressive MS, and of ¹¹C-PIB uptake and MTR for relapsing-remitting MS. MTR in the Thalamus (β= -0.51, p = 0.021) and Corpus Callosum (β= -0.24, p = 0.033) were predictive of cognitive impairment. DTI-FA in the Caudate (β= -26.93, p = 0.006) presented abnormal predictive result.

CONCLUSION

Lower myelin content by ¹¹C-PIB uptake was associated with worse cognitive status. MTR was predictive of cognitive impairment in MS.

Cognitive dysfunction and mortality in multiple sclerosis: Long-term retrospective review

BACKGROUND

Cognitive dysfunction as a predictor of clinical progression and mortality in multiple sclerosis (MS) is still a matter of debate.

OBJECTIVE

The aim of this study was to explore the long-term outcome associated with neuropsychological performance in a cohort of patients with MS.

METHODS

A series of 408 MS patients had previously undergone a comprehensive neuropsychological assessment and a contemporaneous neurological evaluation (T1). A retrospective review of the clinical records was conducted 102-192 months after T1. Demographic and clinical data regarding the last clinical appointment with EDSS measurement (T2) were collected and the date of the last clinical contact or death (TS) was recorded.

RESULTS

This review revealed that cognitive dysfunction (T1) was associated with higher odds of transitioning from relapsing-remitting course to a progressive disease course (adjusted odds ratio (OR) = 2.29, p = 0.043) and higher hazard of death in the total sample (adjusted hazard ratio (HR) = 3.07, p = 0.006) and the progressive disease course subgroup (adjusted HR = 3.68, p = 0.007), even when adjusting for other covariates.

DISCUSSION

The study results demonstrate that cognitive dysfunction in MS is predictive of poorer prognosis and mortality.

“What Is Hidden behind the Mask?” Facial Emotion Recognition at the Time of COVID-19 Pandemic in Cognitively Normal Multiple Sclerosis Patients

Social cognition deficits have been described in people with multiple sclerosis (PwMS), even in absence of a global cognitive impairment, affecting predominantly the ability to adequately process emotions from human faces. The COVID-19 pandemic has forced people to wear face masks that might interfere with facial emotion recognition. Therefore, in the present study, we aimed at investigating the ability of emotion recognition in PwMS from faces wearing masks. We enrolled a total of 42 cognitively normal relapsing–remitting PwMS and a matched group of 20 healthy controls (HCs). Participants underwent a facial emotion recognition task in which they had to recognize from faces wearing or not surgical masks which of the six basic emotions (happiness, anger, fear, sadness, surprise, disgust) was presented. Results showed that face masks negatively affected emotion recognition in all participants (p < 0.001); in particular, PwMS showed a global worse accuracy than HCs (p = 0.005), mainly driven by the “no masked” (p = 0.021) than the “masked” (p = 0.064) condition. Considering individual emotions, PwMS showed a selective impairment in the recognition of fear, compared with HCs, in both the conditions investigated (“masked”: p = 0.023; “no masked”: p = 0.016). Face masks affected negatively also response times (p < 0.001); in particular, PwMS were globally hastier than HCs (p = 0.024), especially in the “masked” condition (p = 0.013). Furthermore, a detailed characterization of the performance of PwMS and HCs in terms of accuracy and response speed was proposed. Results from the present study showed the effect of face masks on the ability to process facial emotions in PwMS, compared with HCs. Healthcare professionals working with PwMS at the time of the COVID-19 outbreak should take into consideration this effect in their clinical practice. Implications in the everyday life of PwMS are also discussed.

Cerebellar Dysfunction in Multiple Sclerosis: Considerations for Research and Rehabilitation Therapy

Introduction. Cerebellar pathology is common among persons with multiple sclerosis (PwMS). The cerebellum is well recognized for its role in motor control and motor learning and cerebellar pathology in multiple sclerosis is associated with enhanced motor impairment and disability progression. The Problem. To mitigate motor disability progression, PwMS are commonly prescribed exercise and task-specific rehabilitation training. Yet, whether cerebellar dysfunction differentially affects rehabilitation outcomes in this population remains unknown. Furthermore, we lack rehabilitation interventions targeting cerebellar dysfunction. The Solution. Here, we summarize the current understanding of the impact of cerebellar dysfunction on motor control, motor training, and rehabilitation in persons with multiple sclerosis. Recommendations. Additionally, we highlight critical knowledge gaps and propose that these guide future research studying cerebellar dysfunction in persons with multiple sclerosis.

A Study Protocol for Occupational Rehabilitation in Multiple Sclerosis

Digital medical solutions can be very helpful in restorative neurology, as they allow the patients to practice their rehabilitation activities remotely. This work discloses ReMoVES, an IoMT system providing telemedicine services, in the context of Multiple Sclerosis rehabilitation, within the frame of the project STORMS. A rehabilitative protocol of exercises can be provided as ReMoVES services and integrated into the Individual Rehabilitation Project as designed by a remote multidimensional medical team. In the present manuscript, the first phase of the study is described, including the definition of the needs to be addressed, the employed technology, the design and the development of the exergames, and the possible practical/professional and academic consequences. The STORMS project has been implemented with the aim to act as a starting point for the development of digital telerehabilitation solutions that support Multiple Sclerosis patients, improving their living conditions. This paper introduces a study protocol and it addresses pre-clinical research needs, where system issues can be studied and better understood how they might be addressed. It also includes tools to favor remote patient monitoring and to support the clinical staff.

Circulatory antioxidant and oxidative stress markers are in correlation with demographics but not cognitive functions in multiple sclerosis patients

BACKGROUND

Multiple sclerosis (MS) is the most common non-traumatic cause of disability in younger adults. MS can be presented with a wide range of symptoms such as cognitive impairment (CI). Oxidative stress (OXS) is a major basis of the pathogenesis of MS. There is a positive correlation between OXS factors and the progression of the disease in MS patients. There are limited studies regarding the role of OXS in MS-related CI. In this study, as an exploratory analysis, we assess the role of endogenous antioxidants and OXS factors in cognitive function, the severity of disability due to MS, and demographic findings in a sample of MS patients.

METHODS

Adult (>18 years old) patients with a definite diagnosis of MS based on 2017 revised MacDonald criteria were included in this study. The neurophysiological assessment was conducted, using the validated Persian version of minimal assessment of cognitive function in multiple sclerosis (MACFIMS) battery, which is composed of seven different tests. Based on the structure of the battery, CI was defined as a failure in at least two different components of the MACFIMS battery. The patients were separated into two groups of CI and non-CI. Examined antioxidant factors included catalase Activity (CAT), Glutathione Peroxidase 1 (GPX1), Glutathione Peroxidase 2 (GPX2), Reduced Glutathione (GSH), Superoxide Dismutase (SOD), and serum total antioxidant capacity (TAC). Malondialdehyde (MDA) was also measured as an OXS marker.

RESULTS

71 patients were involved in this study. The type of MS was relapsing-remitting MS (RRMS) in 80.28% of the participants. Disease duration (P<0.01), type of MS (p<0.01), and EDSS score (p<0.01) were different between CI and non-CI groups, but there were not any significant differences in CAT (p = 0.80), GPX1 (p = 0.71), GPX2 (p = 0.41), GSH (p = 0.96), TAC (p = 0.13), SOD (p = 0.37), and MDA (p = 0.82). A significant difference between RRMS and progressive MS (PMS) patients in the levels of GPX1 (p = 0.01), GPX2 (p = 0.01), and SOD (p = 0.01) was observed. Also, we found higher circulatory levels of CAT (p = 0.02) and TAC (p<0.01) in male MS patients. We found significant correlations between aging and CAT (R = 0.28; p = 0.01), GPX1 (R = 0.36; p<0.01), GPX2 (R = 0.34; p<0.01), and SOD (R = 0.40; p<0.01). EDSS, the duration of the disease, relapse rate, and the number of impaired cognitive tasks were not correlated with any of investigated OXS or antioxidant factors (p>0.05). In terms of a detailed investigation of associations between MACFIMS battery components and levels of OXS and antioxidant factors, there were no significant relations in this regard (p>0.05). Based on the logistic regression multivariate analysis, only disease duration (p = 0.03) and GPX1 (p = 0.01) were independently associated with CI in MS patients in our sample.

CONCLUSION

The circulatory levels of GPX1, GPX2, and SOD are significantly different between RRMS and PMS patients. Neither endogenous antioxidants nor MDA, as an OXS biomarker, are associated with the cognitive function or level of physical disability in MS patients. Limitations of this study suggest a need for future studies in a larger sample of MS patients.

Digging Deeper: Advancements in Visualization of Inhibitory Synapses in Neurodegenerative Disorders

Recent research has provided strong evidence that neurodegeneration may develop from an imbalance between synaptic structural components in the brain. Lately, inhibitory synapses communicating via the neurotransmitters GABA or glycine have come to the center of attention. Increasing evidence suggests that imbalance in the structural composition of inhibitory synapses affect deeply the ability of neurons to communicate effectively over synaptic connections. Progressive failure of synaptic plasticity and memory are thus hallmarks of neurodegenerative diseases. In order to prove that structural changes at synapses contribute to neurodegeneration, we need to visualize single-molecule interactions at synaptic sites in an exact spatial and time frame. This visualization has been restricted in terms of spatial and temporal resolution. New developments in electron microscopy and super-resolution microscopy have improved spatial and time resolution tremendously, opening up numerous possibilities. Here we critically review current and recently developed methods for high-resolution visualization of inhibitory synapses in the context of neurodegenerative diseases. We present advantages, strengths, weaknesses, and current limitations for selected methods in research, as well as present a future perspective. A range of new options has become available that will soon help understand the involvement of inhibitory synapses in neurodegenerative disorders.

Serum Vitamin D as a Marker of Impaired Information Processing Speed and Early Disability in Multiple Sclerosis Patients

Slowed information processing speed (IPS) is the hallmark and first cognitive domain to be altered in multiple sclerosis (MS) patients. Insufficient serum vitamin D was previously associated with disease development, relapses, and progression, but little is reported on cognition. However, vitamin D and cognitive impairment (CI) in other neurodegenerative diseases have already been linked. We explored the possible correlation between vitamin D and IPS at diagnosis and early disability at last follow-up in 81 MS patients. At diagnosis, we collected vitamin D levels and performed a Symbol Digit Modalities Test (SDMT). Raw scores were adjusted for age, gender, and educational level. Early disability was evaluated with MS severity score (MSSS) and age-related MSSS (ARMSS). A total of 71 patients (86.58%) showed hypovitaminosis D (19.71 ± 8.76 ng/mL) and 18 patients (21.95%) had CI. Patients with CI showed severe hypovitaminosis D (p = 0.004). No patients with sufficient vitamin D levels had CI. We found a positive correlation between vitamin D levels at diagnosis and (1) SDMT raw and z-score that persisted after correction for sunlight exposure and MRI baseline characteristics, and (2) EDSS, MSSS, and ARMSS after a mean 2 year follow-up. Low vitamin D levels may affect both cognition and early disability in newly diagnosed MS patients.

Rituximab for people with multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is the most common neurological cause of disability in young adults. Off-label rituximab for MS is used in most countries surveyed by the International Federation of MS, including high-income countries where on-label disease-modifying treatments (DMTs) are available.  OBJECTIVES: To assess beneficial and adverse effects of rituximab as 'first choice' and as 'switching' for adults with MS.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, and trial registers for completed and ongoing studies on 31 January 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and controlled non-randomised studies of interventions (NRSIs) comparing rituximab with placebo or another DMT for adults with MS.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology. We used the Cochrane Collaboration's tool for assessing risk of bias. We rated the certainty of evidence using GRADE for: disability worsening, relapse, serious adverse events (SAEs), health-related quality of life (HRQoL), common infections, cancer, and mortality. We conducted separate analyses for rituximab as 'first choice' or as 'switching', relapsing or progressive MS, comparison versus placebo or another DMT, and RCTs or NRSIs.

MAIN RESULTS

We included 15 studies (5 RCTs, 10 NRSIs) with 16,429 participants of whom 13,143 were relapsing MS and 3286 progressive MS. The studies were one to two years long and compared rituximab as 'first choice' with placebo (1 RCT) or other DMTs (1 NRSI), rituximab as 'switching' against placebo (2 RCTs) or other DMTs (2 RCTs, 9 NRSIs). The studies were conducted worldwide; most originated from high-income countries, six from the Swedish MS register. Pharmaceutical companies funded two studies. We identified 14 ongoing studies. Rituximab as 'first choice' for relapsing MS Rituximab versus placebo: no studies met eligibility criteria for this comparison. Rituximab versus other DMTs: one NRSI compared rituximab with interferon beta or glatiramer acetate, dimethyl fumarate, natalizumab, or fingolimod in active relapsing MS at 24 months' follow-up. Rituximab likely results in a large reduction in relapses compared with interferon beta or glatiramer acetate (hazard ratio (HR) 0.14, 95% confidence interval (CI) 0.05 to 0.39; 335 participants; moderate-certainty evidence). Rituximab may reduce relapses compared with dimethyl fumarate (HR 0.29, 95% CI 0.08 to 1.00; 206 participants; low-certainty evidence) and natalizumab (HR 0.24, 95% CI 0.06 to 1.00; 170 participants; low-certainty evidence). It may make little or no difference on relapse compared with fingolimod (HR 0.26, 95% CI 0.04 to 1.69; 137 participants; very low-certainty evidence). The study reported no deaths over 24 months. The study did not measure disability worsening, SAEs, HRQoL, and common infections. Rituximab as 'first choice' for progressive MS One RCT compared rituximab with placebo in primary progressive MS at 24 months' follow-up. Rituximab likely results in little to no difference in the number of participants who have disability worsening compared with placebo (odds ratio (OR) 0.71, 95% CI 0.45 to 1.11; 439 participants; moderate-certainty evidence). Rituximab may result in little to no difference in recurrence of relapses (OR 0.60, 95% CI 0.18 to 1.99; 439 participants; low-certainty evidence), SAEs (OR 1.25, 95% CI 0.71 to 2.20; 439 participants; low-certainty evidence), common infections (OR 1.14, 95% CI 0.75 to 1.73; 439 participants; low-certainty evidence), cancer (OR 0.50, 95% CI 0.07 to 3.59; 439 participants; low-certainty evidence), and mortality (OR 0.25, 95% CI 0.02 to 2.77; 439 participants; low-certainty evidence). The study did not measure HRQoL. Rituximab versus other DMTs: no studies met eligibility criteria for this comparison. Rituximab as 'switching' for relapsing MS  One RCT compared rituximab with placebo in relapsing MS at 12 months' follow-up. Rituximab may decrease recurrence of relapses compared with placebo (OR 0.38, 95% CI 0.16 to 0.93; 104 participants; low-certainty evidence). The data did not confirm or exclude a beneficial or detrimental effect of rituximab relative to placebo on SAEs (OR 0.90, 95% CI 0.28 to 2.92; 104 participants; very low-certainty evidence), common infections (OR 0.91, 95% CI 0.37 to 2.24; 104 participants; very low-certainty evidence), cancer (OR 1.55, 95% CI 0.06 to 39.15; 104 participants; very low-certainty evidence), and mortality (OR 1.55, 95% CI 0.06 to 39.15; 104 participants; very low-certainty evidence). The study did not measure disability worsening and HRQoL.  Five NRSIs compared rituximab with other DMTs in relapsing MS at 24 months' follow-up. The data did not confirm or exclude a beneficial or detrimental effect of rituximab relative to interferon beta or glatiramer acetate on disability worsening (HR 0.86, 95% CI 0.52 to 1.42; 1 NRSI, 853 participants; very low-certainty evidence). Rituximab likely results in a large reduction in relapses compared with interferon beta or glatiramer acetate (HR 0.18, 95% CI 0.07 to 0.49; 1 NRSI, 1383 participants; moderate-certainty evidence); and fingolimod (HR 0.08, 95% CI 0.02 to 0.32; 1 NRSI, 256 participants; moderate-certainty evidence). The data did not confirm or exclude a beneficial or detrimental effect of rituximab relative to natalizumab on relapses (HR 1.0, 95% CI 0.2 to 5.0; 1 NRSI, 153 participants; very low-certainty evidence). Rituximab likely increases slightly common infections compared with interferon beta or glatiramer acetate (OR 1.71, 95% CI 1.11 to 2.62; 1 NRSI, 5477 participants; moderate-certainty evidence); and compared with natalizumab (OR 1.58, 95% CI 1.08 to 2.32; 2 NRSIs, 5001 participants; moderate-certainty evidence). Rituximab may increase slightly common infections compared with fingolimod (OR 1.26, 95% CI 0.90 to 1.77; 3 NRSIs, 5187 participants; low-certainty evidence). It may make little or no difference compared with ocrelizumab (OR 0.02, 95% CI 0.00 to 0.40; 1 NRSI, 472 participants; very low-certainty evidence). The data did not confirm or exclude a beneficial or detrimental effect of rituximab on mortality compared with fingolimod (OR 5.59, 95% CI 0.22 to 139.89; 1 NRSI, 136 participants; very low-certainty evidence) and natalizumab (OR 6.66, 95% CI 0.27 to 166.58; 1 NRSI, 153 participants; very low-certainty evidence). The included studies did not measure SAEs, HRQoL, and cancer.

AUTHORS' CONCLUSIONS

For preventing relapses in relapsing MS, rituximab as 'first choice' and as 'switching' may compare favourably with a wide range of approved DMTs. A protective effect of rituximab against disability worsening is uncertain. There is limited information to determine the effect of rituximab for progressive MS.  The evidence is uncertain about the effect of rituximab on SAEs. They are relatively rare in people with MS, thus difficult to study, and they were not well reported in studies. There is an increased risk of common infections with rituximab, but absolute risk is small.  Rituximab is widely used as off-label treatment in people with MS; however, randomised evidence is weak. In the absence of randomised evidence, remaining uncertainties on beneficial and adverse effects of rituximab for MS might be clarified by making real-world data available.