Gasdermin D activation in oligodendrocytes and microglia drives inflammatory demyelination in progressive multiple sclerosis.

Neuroinflammation coupled with demyelination and neuro-axonal damage in the central nervous system (CNS) contribute to disease advancement in progressive multiple sclerosis (P-MS). Inflammasome activation accompanied by proteolytic cleavage of gasdermin D (GSDMD) results in cellular hyperactivation and lytic death. Using multiple experimental platforms, we investigated the actions of GSDMD within the CNS and its contributions to P-MS. Brain tissues from persons with P-MS showed significantly increased expression of GSDMD, NINJ1, IL-1ß, and -18 within chronic active demyelinating lesions compared to MS normal appearing white matter and nonMS (control) white matter. Conditioned media (CM) from stimulated GSDMD+/+ human macrophages caused significantly greater cytotoxicity of oligodendroglial and neuronal cells, compared to CM from GSDMD-/- macrophages. Oligodendrocytes and CNS macrophages displayed increased Gsdmd immunoreactivity in the central corpus callosum (CCC) of cuprizone (CPZ)-exposed Gsdmd+/+ mice, associated with greater demyelination and reduced oligodendrocyte precursor cell proliferation, compared to CPZ-exposed Gsdmd-/- animals. CPZ-exposed Gsdmd+/+ mice exhibited significantly increased G-ratios and reduced axonal densities in the CCC compared to CPZ-exposed Gsdmd-/- mice. Proteomic analyses revealed increased brain complement C1q proteins and hexokinases in CPZ-exposed Gsdmd-/- animals. [18F]FDG PET imaging showed increased glucose metabolism in the hippocampus and whole brain with intact neurobehavioral performance in Gsdmd-/- animals after CPZ exposure. GSDMD activation in CNS macrophages and oligodendrocytes contributes to inflammatory demyelination and neuroaxonal injury, offering mechanistic and potential therapeutic insights into P-MS pathogenesis.

Targeting CNS myeloid infiltrates provides neuroprotection in a progressive multiple Sclerosis model.

Demyelination and axonal injury in chronic-progressive Multiple Sclerosis (MS) are presumed to be driven by a neurotoxic bystander effect of meningeal-based myeloid infiltrates. There is an unmet clinical need to attenuate disease progression in such forms of CNS-compartmentalized MS. The failure of systemic immune suppressive treatments has highlighted the need for neuroprotective and repair-inducing strategies. Here, we examined whether direct targeting of CNS myeloid cells and modulating their toxicity may prevent irreversible tissue injury in chronic immune-mediated demyelinating disease. To that end, we utilized the experimental autoimmune encephalomyelitis (EAE) model in Biozzi mice, a clinically relevant MS model. We continuously delivered intracerebroventricularly (ICV) a retinoic acid receptor alpha agonist (RARα), as a potent regulator of myeloid cells, in the chronic phase of EAE. We assessed disease severity and performed pathological evaluations, functional analyses of immune cells, and single-cell RNA sequencing on isolated spinal CD11b + cells. Although initiating treatment in the chronic phase of the disease, the RARα agonist successfully improved clinical outcomes and prevented axonal loss. ICV RARα agonist treatment inhibited pro-inflammatory pathways and shifted CNS myeloid cells toward neuroprotective phenotypes without affecting peripheral infiltrating myeloid cell phenotypes, or peripheral immunity. The treatment regulated cell-death pathways across multiple myeloid cell populations and suppressed apoptosis, resulting in paradoxically marked increased neuroinflammatory infiltrates, consisting mainly of microglia and CNS / border-associated macrophages. This work establishes the notion of bystander neurotoxicity by CNS immune infiltrates in chronic demyelinating disease. Furthermore, it shows that targeting compartmentalized neuroinflammation by selective regulation of CNS myeloid cell toxicity and survival reduces irreversible tissue injury, and may serve as a novel disease-modifying approach.

Serum macrophage migration inhibitory factor levels predict brain atrophy in people with primary progressive multiple sclerosis.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a cytokine linked to multiple sclerosis (MS) progression that is thought to be inhibited by ibudilast. SPRINT-MS was a phase 2 placebo-controlled trial of ibudilast in progressive multiple sclerosis (PMS). OBJECTIVE: To determine whether baseline MIF levels predict imaging outcomes and assess the effects of ibudilast on serum and cerebrospinal fluid (CSF) MIF levels in people with PMS treated with ibudilast. METHODS: Participants in the SPRINT-MS trial were treated with either ibudilast or placebo and underwent brain magnetic resonance imaging (MRI) every 24 weeks over a duration of 96 weeks. MIF was measured in serum and CSF. RESULTS: MIF levels were compared with imaging outcomes in 223 participants from the SPRINT-MS study. In the primary progressive multiple sclerosis (PPMS) cohort, males had higher serum (p < 0.001) and CSF (p = 0.01) MIF levels, as compared with females. Higher baseline serum MIF levels in PPMS were associated with faster brain atrophy (beta = -0.113%, 95% confidence interval (CI): -0.204% to -0.021%; p = 0.016). These findings were not observed in secondary progressive multiple sclerosis (SPMS). Ibudilast did not affect either serum or CSF MIF levels. CONCLUSIONS: Serum MIF levels were associated with male sex and predicted brain atrophy in PPMS, but not SPMS. Ibudilast did not demonstrate an effect on MIF levels, as compared with placebo, although we cannot exclude a functional effect.

Real-world data on siponimod-related lymphopenia among people with secondary progressive multiple sclerosis.

BACKGROUND: Siponimod-related lymphopenia in real-world clinical practice has implications for dose adjustment and infection risk. OBJECTIVE: To characterise siponimod-related lymphopenia in people with secondary progressive multiple sclerosis (pwSPMS). METHODS: This is a retrospective cohort of 188 pwSPMS. The development of grade 4 lymphopenia was interrogated with Kaplan-Meier survival analysis and binary logistic regression. RESULTS: Lymphopenia develops soon after commencing siponimod. In total, 15 (8.5%) of 176 experienced grade 4 lymphopenia at 1 month after initiation. There were no clinically significant associations between patient characteristics and development of grade 4 lymphopenia. CONCLUSION: Grade 4 lymphopenia can occur soon after siponimod initiation and cannot be predicted.

Ibudilast reduces slowly enlarging lesions in progressive multiple sclerosis.

BACKGROUND: Ibudilast has shown beneficial effects on several imaging outcomes in progressive multiple sclerosis (MS). Slowly enlarging lesions are a proposed imaging biomarker of compartmentalized inflammation within chronic active lesions. OBJECTIVE: To assess the treatment effect of ibudilast on slowly enlarging lesion volumes over 96 weeks from a phase II clinical trial of ibudilast (Secondary and Primary Progressive Ibudilast NeuroNEXT Trial in Multiple Sclerosis [SPRINT-MS]). METHODS: In total, 255 participants with progressive MS from 28 sites were randomized to oral ibudilast or placebo. Participants with at least four analyzable magnetic resonance imaging (MRI) were included. Slowly enlarging lesions were quantified using Jacobian determinant maps. A linear model was used to assess the effect of ibudilast. Magnetization transfer ratio within slowly enlarging lesions was assessed to determine the effect of ibudilast on tissue integrity. RESULTS: In total, 195 participants were included in this analysis. Ibudilast significantly decreased slowly enlarging lesion volume (23%, p = 0.003). Ibudilast also reduced magnetization transfer ratio change in slowly enlarging lesions: 0.22%/year, p = 0.04. CONCLUSION: Ibudilast showed a significant effect on baseline volume of lesions that were slowly enlarging and magnetization transfer ratio in slowly enlarging lesions. The results support the use of slowly enlarging lesions for assessment of compartmentalized inflammation represented by chronic active lesions and provide further support for the neuroprotective effects of ibudilast in progressive MS.

Treatment reduces the incidence of newly appearing multiple sclerosis lesions evolving into chronic active, slowly expanding lesions: A retrospective analysis.

BACKGROUND AND PURPOSE: Newly appearing lesions in multiple sclerosis (MS) may evolve into chronically active, slowly expanding lesions (SELs), leading to sustained disability progression. The aim of this study was to evaluate the incidence of newly appearing lesions developing into SELs, and their correlation to clinical evolution and treatment. METHODS: A retrospective analysis of a fingolimod trial in primary progressive MS (PPMS; INFORMS, NCT00731692) was undertaken. Data were available from 324 patients with magnetic resonance imaging scans up to 3 years after screening. New lesions at year 1 were identified with convolutional neural networks, and SELs obtained through a deformation-based method. Clinical disability was assessed annually by Expanded Disability Status Scale (EDSS), Nine-Hole Peg Test, Timed 25-Foot Walk, and Paced Auditory Serial Addition Test. Linear, logistic, and mixed-effect models were used to assess the relationship between the Jacobian expansion in new lesions and SELs, disability scores, and treatment status. RESULTS: One hundred seventy patients had ≥1 new lesions at year 1 and had a higher lesion count at screening compared to patients with no new lesions (median = 27 vs. 22, p = 0.007). Among the new lesions (median = 2 per patient), 37% evolved into definite or possible SELs. Higher SEL volume and count were associated with EDSS worsening and confirmed disability progression. Treated patients had lower volume and count of definite SELs (ß = -0.04, 95% confidence interval [CI] = -0.07 to -0.01, p = 0.015; ß = -0.36, 95% CI = -0.67 to -0.06, p = 0.019, respectively). CONCLUSIONS: Incident chronic active lesions are common in PPMS, and fingolimod treatment can reduce their number.

Exploring the therapeutic potential of autologous hematopoietic stem cell transplantation in progressive multiple sclerosis-a systematic review.

BACKGROUND AND PURPOSE: The aim was to determine the value of autologous haematopoietic stem cell transplantation (aHSCT) as a therapeutic intervention for progressive multiple sclerosis (PMS) based on a systematic review of the current literature. METHODS: All studies from the databases PubMed and Google Scholar published in English before February 2024 which provided individual data for PMS patients were systematically reviewed. PICO was defined as population (P), primary progressive MS and secondary progressive MS patients; intervention (I), treatment with aHSCT; comparison (C), none, disease-modifying therapy treated/relapsing-remitting MS cohorts if available; outcome (O), transplant-related mortality, progression-free survival (PFS) and no evidence of disease activity. RESULTS: A total of 15 studies met the criteria including 665 patients with PMS (74 primary progressive MS, 591 secondary progressive MS) and 801 patients with relapsing-remitting MS as controls. PFS data were available for 647 patients. PMS patients showed more severe disability at baseline than relapsing-remitting MS patients. The average transplant-related mortality for PMS in 10 studies was 1.9%, with 10 deaths in 528 patients. PFS ranged from 0% to 78% in PMS groups 5 years after treatment initiation, demonstrating a high variability. No evidence of disease activity scores at 5 years ranged from 0% to 75%. CONCLUSION: Based on the available data, aHSCT does not halt progression in people with PMS. However, there appears to be evidence of improved outcome in selected patients. Due to the heterogeneity of the available data, more comprehensive clinical trials assessing the efficacy of aHSCT across different patient groups are urgently needed to reduce variability and improve patient stratification.

Cerebrospinal fluid immunoglobulins in primary progressive multiple sclerosis are pathogenic.

Multiple sclerosis is clinically characterized by relapses and remissions (relapsing-remitting multiple sclerosis) that over time may evolve to a progressive course (secondary progressive multiple sclerosis) or as having a progressive course from disease onset (primary progressive multiple sclerosis). At present, it is not definitively known whether these clinical entities constitute a single pathological disease or whether these manifestations represent two distinct disease entities sharing inflammatory demyelination as a pathological feature. Here we show using a novel mouse model that CSF of primary progressive multiple sclerosis patients is unique in its capacity to induce motor disability and spinal cord pathology including demyelination, impaired remyelination, reactive astrogliosis and axonal damage. Notably, removal of immunoglobulin G from primary progressive multiple sclerosis CSF via filtration or immunodepletion attenuates its pathogenic capacity. Furthermore, injection of recombinant antibodies derived from primary progressive multiple sclerosis CSF recapitulates the pathology. Our findings suggest that the clinical and pathological features of primary progressive multiple sclerosis are antibody-mediated and pathogenically distinct from relapsing-remitting and secondary progressive multiple sclerosis. Our study has potentially important implications for the development of specific therapies for patients with primary progressive multiple sclerosis.

The risk of secondary progressive multiple sclerosis is geographically determined but modifiable.

Geographical variations in the incidence and prevalence of multiple sclerosis have been reported globally. Latitude as a surrogate for exposure to ultraviolet radiation but also other lifestyle and environmental factors are regarded as drivers of this variation. No previous studies evaluated geographical variation in the risk of secondary progressive multiple sclerosis, an advanced form of multiple sclerosis that is characterized by steady accrual of irreversible disability. We evaluated differences in the risk of secondary progressive multiple sclerosis in relation to latitude and country of residence, modified by high-to-moderate efficacy immunotherapy in a geographically diverse cohort of patients with relapsing-remitting multiple sclerosis. The study included relapsing-remitting multiple sclerosis patients from the global MSBase registry with at least one recorded assessment of disability. Secondary progressive multiple sclerosis was identified as per clinician diagnosis. Sensitivity analyses used the operationalized definition of secondary progressive multiple sclerosis and the Swedish decision tree algorithm. A proportional hazards model was used to estimate the cumulative risk of secondary progressive multiple sclerosis by country of residence (latitude), adjusted for sex, age at disease onset, time from onset to relapsing-remitting phase, disability (Multiple Sclerosis Severity Score) and relapse activity at study inclusion, national multiple sclerosis prevalence, government health expenditure, and proportion of time treated with high-to-moderate efficacy disease-modifying therapy. Geographical variation in time from relapsing-remitting phase to secondary progressive phase of multiple sclerosis was modelled through a proportional hazards model with spatially correlated frailties. We included 51 126 patients (72% female) from 27 countries. The median survival time from relapsing-remitting phase to secondary progressive multiple sclerosis among all patients was 39 (95% confidence interval: 37 to 43) years. Higher latitude [median hazard ratio = 1.21, 95% credible interval (1.16, 1.26)], higher national multiple sclerosis prevalence [1.07 (1.03, 1.11)], male sex [1.30 (1.22, 1.39)], older age at onset [1.35 (1.30, 1.39)], higher disability [2.40 (2.34, 2.47)] and frequent relapses [1.18 (1.15, 1.21)] at inclusion were associated with increased hazard of secondary progressive multiple sclerosis. Higher proportion of time on high-to-moderate efficacy therapy substantially reduced the hazard of secondary progressive multiple sclerosis [0.76 (0.73, 0.79)] and reduced the effect of latitude [interaction: 0.95 (0.92, 0.99)]. At the country-level, patients in Oman, Tunisia, Iran and Canada had higher risks of secondary progressive multiple sclerosis relative to the other studied regions. Higher latitude of residence is associated with a higher probability of developing secondary progressive multiple sclerosis. High-to-moderate efficacy immunotherapy can mitigate some of this geographically co-determined risk.

The association between weight during early life and multiple sclerosis onset in a nationwide Dutch birth year cohort.

BACKGROUND: The relationship between being overweight during early life and disease course in multiple sclerosis (MS) is unresolved. We investigated the association between being overweight or obese during early life (childhood and adolescence) and MS case status, age of first symptom onset and onset type in people with MS (pwMS) of the same birth year. METHODS: We enrolled 363 PwMS and 125 healthy controls (HC) from Project Y, a Dutch population-based cross-sectional cohort study including all PwMS born in 1966 and age and sex-matched HC. The associations between weight during childhood and adolescence (non-overweight vs. overweight or obese) and MS, age at symptom onset and onset type (relapsing vs. progressive) were assessed using logistic and linear regressions. In addition, sex-separated associations were explored. RESULTS: Being overweight or obese during childhood (OR = 2.82, 95% CI 1.17-6.80) and adolescence (OR = 2.45, 95% CI 1.13-5.34) was associated with developing MS. Furthermore, being overweight or obese during adolescence was associated with a younger age of onset (ß = -0.11, p = 0.041). Of all 47 patients with a primary progressive (PP) onset type, only one patient (2.1%) was overweight or obese during childhood, whereas 45 patients with a relapsing remitting (RR) onset (14.3%) were overweight or obese during childhood (PP vs. RR p = 0.017; PP vs. HC p = 0.676; RR vs. HC, p = 0.015). However, using logistic regression analysis we did not find evidence of a significant association. CONCLUSION: In a nationwide population-based birth year cohort, being overweight or obese during childhood or adolescence is associated with MS prevalence and an earlier age of onset, but does not seem to associate with the type of onset.

Involvement of cytotoxic Eomes-expressing CD4+ T cells in secondary progressive multiple sclerosis.

Multiple sclerosis (MS), a putative autoimmune disease of the central nervous system (CNS), commonly presents as relapsing-remitting MS (RRMS), characterized by recurrent episodes of peripheral disabling symptoms resulting from inflammatory CNS damage. Many RRMS patients transition to a chronic disease course with progressive neurological dysfunctions (secondary progressive MS, SPMS), with the progression rate varying between patients and over time. SPMS pathogenesis is now linked to immune-cell-mediated processes, although the mechanisms driving SPMS transition and progression remain elusive, and SPMS lacks biomarkers and effective treatments. We report the crucial involvement of cytotoxic CD4+ T cells expressing Eomes (Eomes+ Th cells) in SPMS pathogenesis-a Th cell subset previously identified in a mouse model of late/chronic autoimmune CNS inflammation. Few Eomes+ Th cells circulate in RRMS patient peripheral blood (n = 44), primary progressive MS (PPMS) patients (n = 25), or healthy controls (n = 42), but Eomes+ Th cells were significantly increased in SPMS (n = 105, P < 0.0001). Strikingly, lymphocytes isolated from SPMS autopsy brain samples revealed CD4+ T cells infiltrating CNS that coexpressed Eomes and the cytotoxic molecule granzyme B. In particular, the Eomes+ Th cell levels were increased in SPMS patients in progressive disease phases versus SPMS patients without current disability increases (P < 0.0001). Moreover, Eomes level acted as a biomarker to predict SPMS patients at risk of disease worsening with over 80% accuracy (ROC-AUC = 0.8276). Overall, our results indicate that granzyme B-expressing Eomes+ T helper cells are involved in the pathogenesis of SPMS, with significant implications for SPMS biomarkers and therapeutic targets.

In Silico Analysis Highlights Potential Predictive Indicators Associated with Secondary Progressive Multiple Sclerosis.

Multiple sclerosis (MS) is a complex inflammatory disease affecting the central nervous system. Most commonly, it begins with recurrent symptoms followed by partial or complete recovery, known as relapsing-remitting MS (RRMS). Over time, many RRMS patients progress to secondary progressive MS (SPMS), marked by gradual symptom deterioration. The factors triggering this transition remain unknown, lacking predictive biomarkers. This study aims to identify blood biomarkers specific to SPMS. We analyzed six datasets of SPMS and RRMS patients' blood and brain tissues, and compared the differential expressed genes (DEGs) obtained to highlight DEGs reflecting alterations occurring in both brain and blood tissues and the potential biological processes involved. We observed a total of 38 DEGs up-regulated in both blood and brain tissues, and their interaction network was evaluated through network analysis. Among the aforementioned DEGs, 21 may be directly involved with SPMS transition. Further, we highlighted three biological processes, including the calcineurin-NFAT pathway, related to this transition. The investigated DEGs may serve as a promising means to monitor the transition from RRMS to SPMS, which is still elusive. Given that they can also be sourced from blood samples, this approach could offer a relatively rapid and convenient method for monitoring MS and facilitating expedited assessments.

The Use of Nitrosative Stress Molecules as Potential Diagnostic Biomarkers in Multiple Sclerosis.

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) of still unclear etiology. In recent years, the search for biomarkers facilitating its diagnosis, prognosis, therapy response, and other parameters has gained increasing attention. In this regard, in a previous meta-analysis comprising 22 studies, we found that MS is associated with higher nitrite/nitrate (NOx) levels in the cerebrospinal fluid (CSF) compared to patients with non-inflammatory other neurological diseases (NIOND). However, many of the included studies did not distinguish between the different clinical subtypes of MS, included pre-treated patients, and inclusion criteria varied. As a follow-up to our meta-analysis, we therefore aimed to analyze the serum and CSF NOx levels in clinically well-defined cohorts of treatment-naïve MS patients compared to patients with somatic symptom disorder. To this end, we analyzed the serum and CSF levels of NOx in 117 patients (71 relapsing-remitting (RR) MS, 16 primary progressive (PP) MS, and 30 somatic symptom disorder). We found that RRMS and PPMS patients had higher serum NOx levels compared to somatic symptom disorder patients. This difference remained significant in the subgroup of MRZ-negative RRMS patients. In conclusion, the measurement of NOx in the serum might indeed be a valuable tool in supporting MS diagnosis.

Metabolic syndrome and the phenotype of multiple sclerosis.

BACKGROUND: Comorbidities, particularly vascular comorbidities, have been shown to exacerbate the progression of disability in multiple sclerosis (MS). Metabolic syndrome (MetS) is a cluster of conditions including abdominal obesity, insulin resistance, atherogenic dyslipidemia, and vascular dysfunction, which contribute to vascular morbidity and chronic inflammation. OBJECTIVE: To describe the characteristics of MetS in a cohort of MS patients and evaluate its relationship with the MS phenotype. METHODS: A monocentric cohort study was conducted on MS patients, collecting demographic, clinical, radiological, and therapeutic data, as well as metabolic data including waist circumference, blood pressure, serum triglycerides, high-density lipoprotein cholesterol, and fasting blood glucose. RESULTS: Among the 84 patients included in the study, 27% were diagnosed with MetS. MetS was found to be associated with secondary progressive MS (SPMS). Patients with SPMS had a higher prevalence of MetS compared to those with relapsing-remitting MS (RRMS), even after adjusting for disease duration. While MetS was associated with Expanded Disability Status Scale (EDSS) progression in the 3-year period according to univariate analysis, it did not show a significant association with disease activity. CONCLUSION: This study provides evidence supporting the connection between MetS and the progression of disability in MS, independent of disease relapse activity.

Symbol Digit Modalities Test in progressive multiple sclerosis.

INTRODUCTION: The Symbol Digit Modalities Test (SDMT) is a highly sensitive neuropsychological tool used for the assessment of information processing speed (IPS) in various neurological disorders. STATE OF THE ART: In this review, we have focused on the current knowledge regarding the use of SDMT selectively in the evaluation of progressive multiple sclerosis (PMS) patients. A literature review was performed regarding the application of SDMT in PMS, with a focus on the primary progressive and secondary progressive subtypes. Relationships of diverse disease-associated factors with SDMT have been described, including disease course, imaging findings, molecular biomarkers, treatment and others. CLINICAL IMPLICATIONS: SDMT is a very useful and easily applicable instrument in the diagnostic armamentarium of neurologists and neuropsychologists. It is especially valuable in the evaluation of PMS patients, in whom the prevalence of IPS deficits is higher than in relapsing-remitting multiple sclerosis subjects or in healthy individuals. FUTURE DIRECTIONS: An emphasis should be laid on larger study groups and differentiating between individual PMS subtypes and their separate analysis in the context of cognitive assessment.

Longitudinal Metabolite Changes in Progressive Multiple Sclerosis: A Study of 3 Potential Neuroprotective Treatments.

BACKGROUND: 1 H-magnetic resonance spectroscopy (1 H-MRS) may provide a direct index for the testing of medicines for neuroprotection and drug mechanisms in multiple sclerosis (MS) through measures of total N-acetyl-aspartate (tNAA), total creatine (tCr), myo-inositol (mIns), total-choline (tCho), and glutamate + glutamine (Glx). Neurometabolites may be associated with clinical disability with evidence that baseline neuroaxonal integrity is associated with upper limb function and processing speed in secondary progressive MS (SPMS). PURPOSE: To assess the effect on neurometabolites from three candidate drugs after 96-weeks as seen by 1 H-MRS and their association with clinical disability in SPMS. STUDY-TYPE: Longitudinal. POPULATION: 108 participants with SPMS randomized to receive neuroprotective drugs amiloride [mean age 55.4 (SD 7.4), 61% female], fluoxetine [55.6 (6.6), 71%], riluzole [54.6 (6.3), 68%], or placebo [54.8 (7.9), 67%]. FIELD STRENGTH/SEQUENCE: 3-Tesla. Chemical-shift-imaging 2D-point-resolved-spectroscopy (PRESS), 3DT1. ASSESSMENT: Brain metabolites in normal appearing white matter (NAWM) and gray matter (GM), brain volume, lesion load, nine-hole peg test (9HPT), and paced auditory serial addition test were measured at baseline and at 96-weeks. STATISTICAL TESTS: Paired t-test was used to analyze metabolite changes in the placebo arm over 96-weeks. Metabolite differences between treatment arms and placebo; and associations between baseline metabolites and upper limb function/information processing speed at 96-weeks assessed using multiple linear regression models. P-value<0.05 was considered statistically significant. RESULTS: In the placebo arm, tCho increased in GM (mean difference = -0.32 IU) but decreased in NAWM (mean difference = 0.13 IU). Compared to placebo, in the fluoxetine arm, mIns/tCr was lower (ß = -0.21); in the riluzole arm, GM Glx (ß = -0.25) and Glx/tCr (ß = -0.29) were reduced. Baseline tNAA(ß = 0.22) and tNAA/tCr (ß = 0.23) in NAWM were associated with 9HPT scores at 96-weeks. DATA CONCLUSION: 1 H-MRS demonstrated altered membrane turnover over 96-weeks in the placebo group. It also distinguished changes in neuro-metabolites related to gliosis and glutaminergic transmission, due to fluoxetine and riluzole, respectively. Data show tNAA is a potential marker for upper limb function. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 4.

Progressive motor impairment from "critical" demyelinating lesions of the cervicomedullary junction.

BACKGROUND: Progressive motor impairment anatomically associated with a "critical" lesion has been described in primary demyelinating disease. Most "critical" lesions occur within the spinal cord. OBJECTIVE: To describe the clinical and radiological features of "critical" lesions of the cervicomedullary junction (CMJ). METHODS: Observational study on people presenting with a CMJ lesion associated with primary demyelinating disease-related progressive motor impairment. Clinical data were extracted by chart review. Brain and spinal cord magnetic resonance images were reviewed to characterize the CMJ lesion and determine additional demyelination burden. RESULTS: Forty-one people were included: 29 (71%) had progression from onset and 12 (29%) had a relapse onset (secondary progressive) course. Most had progressive hemiparesis (21 (51%)) or progressive quadriparesis (15 (37%)) with a median Expanded Disability Status Scale (EDSS) of 5.5 (2.0-8.5) at last follow-up. No "critical" CMJ lesion enhanced; most were bilateral (25 (61%)). Brain magnetic resonance images were otherwise normal in 16 (39%) or with a restricted demyelination burden in 15 (37%). Cervical and thoracic cord MRIs were without additional lesions in 25 (61%) and 22/37 (59%), respectively. CONCLUSION: CMJ "critical" lesions can correlate with progressive motor impairment even with few or no additional magnetic resonance imaging (MRI) lesions. Lesion location is an important determinant of progressive motor impairment in demyelinating disease.

Association of MRI leptomeningeal enhancement with disability worsening in progressive multiple sclerosis: A clinical and post-mortem study.

BACKGROUND: Leptomeningeal enhancement (LME) has been described as a biomarker of meningeal inflammation in multiple sclerosis (MS). OBJECTIVE: The aim of this study was to (1) assess if LME is predictive of disability worsening in progressive MS (pMS) patients and (2) investigate the pathological substrates of LME in an independent post-mortem MS series. METHODS: In total, 115 pMS patients were imaged yearly with 1.5T MRI, using post-contrast CUBE 3D FLAIR for LME detection. Endpoint: to identify the baseline variables predictive of confirmed disability worsening (CDW) at 24 months follow-up. Post-mortem, inflammation, and structural changes of the leptomeninges were assessed in 12 MS/8 control brains. RESULTS: LME (27% of patients at baseline) was associated with higher EDSS and lower brain volume (nBV). LME was unchanged in most patients over follow-up. LME at baseline MRI was independently associated with higher risk of 24 months CDW (HR 3.05, 95% CI 1.36-6.84, p = 0.007) in a Cox regression, including age, nBV, T2 lesion volume, high-efficacy treatments, and MRI disease activity. Post-mortem, focal structural changes (fibrosis) of the leptomeninges were observed in MS, usually associated with inflammation (Kendall's Tau 0.315, p < 0.0001). CONCLUSIONS: LME is frequently detected in pMS patients using 1.5T MRI and is independently predictive of disability progression. LME could result from both focal leptomeningeal post-inflammatory fibrosis and inflammation.

Do the current MS clinical course descriptors need to change and if so how? A survey of the MS community.

BACKGROUND AND OBJECTIVES: The current clinical course descriptors of multiple sclerosis (MS) include a combination of clinical and magnetic resonance imaging (MRI) features. Recently there has been a growing call to base these descriptors more firmly on biological mechanisms. We investigated the implications of proposing a new mechanism-driven framework for describing MS. METHODS: In a web-based survey, multiple stakeholders rated the need to change current MS clinical course descriptors, the definitions of disease course and their value in clinical practice and related topics. RESULTS: We received 502 responses across 49 countries. In all, 77% of the survey respondents supported changing the current MS clinical course descriptors. They preferred a framework that informs treatment decisions, aids the design and conduct of clinical trials, allows patients to understand their disease, and links disease mechanisms and clinical expression of disease. Clinical validation before dissemination and ease of communication to patients were rated as the most important aspects to consider when developing any new framework for describing MS. CONCLUSION: A majority of MS stakeholders agreed that the current MS clinical course descriptors need to change. Any change process will need to engage a wide range of affected stakeholders and be guided by foundational principles.

Effect of ibudilast on thalamic magnetization transfer ratio and volume in progressive multiple sclerosis.

BACKGROUND: Thalamic volume (TV) is a sensitive biomarker of disease burden of injury in multiple sclerosis (MS) and appears to reflect overall lesion loads. Ibudilast showed significant treatment effect on brain atrophy and magnetization transfer ratio (MTR) of normal-appearing brain tissue but not in new/enlarging T2 lesion in the SPRINT-MS randomized clinical trial. OBJECTIVE: To evaluate the effect of ibudilast on thalamic tissue integrity and volume in the SPRINT-MS. METHODS: A total of 255 participants with progressive MS were randomized to oral ibudilast or placebo, and thalamic MTR and normalized TV over 96 weeks were quantified. Mixed-effect modeling assessed treatment effects on the thalamic MTR and TV, separately. Similarly, the measures were compared between the participants with confirmed disability progression (CDP). RESULTS: Ibudilast's treatment effect was observed compared to placebo for thalamic MTR (p = 0.03) but not for TV (p = 0.68) while TV correlated with T2 lesion volume (p < 0.001). CDP associated with thalamic MTR (p = 0.04) but not with TV (p = 0.7). CONCLUSION: Ibudilast showed an effect on thalamic MTR, which was associated with CDP, suggesting a clinically relevant effect on thalamic tissue integrity. However, the treatment effect was not observed in TV, suggesting that thalamic atrophy is more closely associated with global inflammatory activity than local tissue integrity. CLINICALTRIALS.GOV: NCT01982942.