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Background: While glucagon-like peptide-1 agonist medications (GLP-1s) are on the rise, their safety and efficacy have not been studied in people with MS (PwMS)., Objective: To investigate any adverse effects of GLP-1 medications in the MS population as well as their effectiveness for weight loss and vitamin D augmentation., Methods: We retrospectively identified PwMS who utilized a GLP-1 medication from 2006 to 2024. Wilcoxon signed rank tests for paired samples were used to compare pre- and post-GLP-1 body mass index (BMI), expanded disability status scale (EDSS), timed 25-foot walk (25FTW), and mean vitamin D values. Additional safety outcomes assessed during GLP-1 treatment were deaths, hospitalizations, clinician-confirmed relapses, and new MRI activity., Results: Following GLP-1 initiation, PwMS had a decrease in BMI (mean % BMI loss 3.7, p = 0.001) and an increase in vitamin D values (mean increase of 8.1 ng/mL, p = 0.0002), while no change in EDSS or T25FW was seen. There were no hospitalizations or deaths after GLP-1 initiation., Conclusion: GLP-1 medications are safe and effective in PwMS and can help augment vitamin D levels., Competing Interests: Declaration of competing interest The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: J.A.S. has grant funding from the National MS Society and has consulted for Biogen, Genentech, Teva, Banner, Sanofi, and Cellgene. The remaining authors have no conflicts to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: 11 C-PBR28 positron emission tomography (PET), targeting the translocator protein, and paramagnetic rim lesions (PRL) have emerged as promising imaging markers of MS chronic inflammation. No consensus on which is the optimal marker exists., Objectives: To investigate the ability of 11 C-PBR28 PET and PRL assessment to identify chronic inflammation in white matter (WM) MS lesions and their relation to neurological impairment., Methods: Based on 11 C-PBR28 uptake, brain WM lesions from 30 MS patients were classified as PET active or inactive. The PRL presence was assessed on 7T phase reconstructions, T1/T2 ratio was calculated to measure WM microstructural integrity., Results: Less than half (44%) of non-PRL WM lesions were active on 11 C-PBR28 imaging either throughout the lesion (whole active) or at its periphery. PET peripherally active lesions and PRL did not differ in T1/T2 ratio and 11 C-PBR28 uptake. A positive correlation was observed between PRL and active PET lesion count. Whole active PET lesion volume was the strongest predictor (β = 0.97, p < 0.001) of increased Expanded Disability Status Scale scores., Conclusion: 11 C-PBR28 imaging reveals more active WM lesions than 7T PRL assessment. Although PRL and PET active lesion counts are related, neurological disability is better explained by PET whole active lesion volume., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: C.A.T. has received research support from Genentech; E.H. has received research support from the NMSS (FG-1507-05459, TA-1905-34039); J.A.S. has consulted for Novartis, Biogen, Celgene, and Genentech; T.G. is a recipient of the Grant for Multiple Sclerosis Innovation, funded by Merck; C.M. has received research support from Genentech. The remaining authors have nothing to disclose.

Background: Obstructive sleep apnea (OSA) is more common in patients with multiple sclerosis (MS) than in the general population, which suggests MS may predispose patients to OSA. However, the relationships between MS treatment, disease activity, disease severity, fatigue, and OSA are unknown., Objectives: To evaluate the connections between OSA risk, MS fatigue, and MS severity, controlling for well-established risk factors for OSA in the general population., Methods: We administered OSA and fatigue-related questionnaires to patients with MS and collected relevant demographic and clinical data. Then, we utilized multivariate logistic regression to examine relationships between OSA risk and MS disease severity., Results: We identified an inverse correlation between medication possession ratio (MPR) and high OSA risk. Statistical models also demonstrated a positive correlation between fatigue and nonwhite race with high OSA risk, controlling for male sex, younger age, and body mass index (BMI)., Conclusion: We identified disease-modifying therapy (DMT) underutilization, fatigue, and nonwhite race as predictors of high OSA risk in patients with MS. These findings support aggressive treatment of MS to avoid risk of comorbid OSA and MS-induced fatigue., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript., (Copyright © 2024 Elsevier B.V. All rights reserved.)

We report two patients who developed atypical, disseminated herpes zoster infections while on dimethyl fumarate (DMF) treatment, one with varicella zoster virus (VZV) encephalitis and another with herpes zoster oticus resulting in lasting motor and sensory deficits. We recommend vaccination against VZV prior to DMF initiation be incorporated as standard of care, as ensuring patients are protected against VZV before starting DMF can prevent such severe outcomes., (© 2024. The Author(s) under exclusive licence to The Journal of NeuroVirology, Inc.)

Background: Diroximel fumarate (DRF) and dimethyl fumarate (DMF) are similar disease-modifying therapies (DMTs) that reduce disease activity in patients with relapsing-remitting multiple sclerosis (MS). We expect that patients on DRF would experience a similar incidence and severity of lymphopenia, given that it is a well-documented side effect of DMF treatment., Methods: We utilized linear mixed-effects models to test for differences in white blood cell count (WBC), absolute lymphocyte count (ALC), absolute CD3+ count, absolute CD4+ count, and absolute CD8+ count over time in clinically stable patients with MS on DMF who switched to DRF., Results: Twenty-two patients with MS who were clinically stable on DMF switched to DRF. Linear mixed-effects models showed a decrease in ALC when switching medications (β = -225.70, p < 0.040). In addition, the models showed a decrease in absolute CD8+ counts after switches from DMF to DRF (β = -85.59, p = 0.034)., Conclusion: Patients with MS who are stable on DMF and switch to DRF may experience worsening of lymphopenia and lower absolute CD8+ counts, which may increase their risk of opportunistic infections. These findings indicate that close lymphocyte subset monitoring is clinically important when switching patients with MS from DMF to DRF., Competing Interests: Declaration of competing interest We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled, “Worsening of lymphopenia in patients with multiple sclerosis when switched from dimethyl fumarate to diroximel fumarate.”, (Copyright © 2024 Elsevier B.V. All rights reserved.)

Cases of herpes zoster (HZ) in patients with MS on natalizumab (NTZ) have been documented. In this study, we assessed lymphocyte subsets in NTZ-treated patients with HZ compared to matched controls without HZ. Twenty unvaccinated patients developed HZ while on NTZ for an incidence rate of 12.3 per 1000 patient-years. These patients had lower CD8+% and higher CD4+:CD8+ ratios ( p ⩽ 0.01) than non-HZ matched controls. Two patients with relapsing-remitting MS developed HZ twice while on NTZ. These findings underscore the importance of pre-NTZ HZ vaccination due to potential HZ risk., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: J.A.S. has grant funding from the National MS Society and has consulted for Biogen, Genentech, Teva, Banner, Sanofi, and Cellgene. The remaining authors have no conflicts to declare.

Compartmentalized meningeal inflammation is thought to represent one of the key players in the pathogenesis of cortical demyelination in multiple sclerosis. PET targeting the 18 kDa mitochondrial translocator protein (TSPO) is a molecular-specific approach to quantifying immune cell-mediated density in the cortico-meningeal tissue compartment in vivo. This study aimed to characterize cortical and meningeal TSPO expression in a heterogeneous cohort of multiple sclerosis cases using in vivo simultaneous MR-PET with 11C-PBR28, a second-generation TSPO radioligand, and ex vivo immunohistochemistry. Forty-nine multiple sclerosis patients (21 with secondary progressive and 28 with relapsing-remitting multiple sclerosis) with mixed or high affinity binding for 11C-PBR28 underwent 90-min 11C-PBR28 simultaneous MR-PET. Tracer binding was measured using 60-90 min normalized standardized uptake value ratios sampled at mid-cortical depth and ∼3 mm above the pial surface. Data in multiple sclerosis patients were compared to 21 age-matched healthy controls. To characterize the nature of 11C-PBR28 PET uptake, the meningeal and cortical lesion cellular expression of TSPO was further described in post-mortem brain tissue from 20 cases with secondary progressive multiple sclerosis and five age-matched healthy donors. Relative to healthy controls, patients with multiple sclerosis exhibited abnormally increased TSPO signal in the cortex and meningeal tissue, diffusively in progressive disease and more localized in relapsing-remitting multiple sclerosis. In multiple sclerosis, increased meningeal TSPO levels were associated with increased Expanded Disability Status Scale scores (P = 0.007, by linear regression). Immunohistochemistry, validated using in situ sequencing analysis, revealed increased TSPO expression in the meninges and adjacent subpial cortical lesions of post-mortem secondary progressive multiple sclerosis cases relative to control tissue. In these cases, increased TSPO expression was related to meningeal inflammation. Translocator protein immunostaining was detected on meningeal MHC-class II+ macrophages and cortical-activated MHC-class II+ TMEM119+ microglia. In vivo arterial blood data and neuropathology showed that endothelial binding did not significantly account for increased TSPO cortico-meningeal expression in multiple sclerosis. Our findings support the use of TSPO-PET in multiple sclerosis for imaging in vivo inflammation in the cortico-meningeal brain tissue compartment and provide in vivo evidence implicating meningeal inflammation in the pathogenesis of the disease., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Endometriosis (EMS) is pain syndrome in which endometrial tissue grows outside the uterus. EMS is associated with an increased risk of multiple sclerosis (MS), a demyelinating disease of the central nervous system., Objective: To characterize clinical phenotypes of a cohort of patients with both EMS and MS compared to a cohort of matched controls with only MS., Methods: We retrospectively identified patients with EMS and MS at Beth Israel Deaconess Medical Center (BIDMC). We collected data on EMS treatments and analyzed differences in histories of gynecological cancer, smoking, fatigue, anxiety, depression, headache, and neuropathic pain compared to matched controls. We used Wilcoxon signed rank tests for paired samples to compare Expanded Disability Status Scores (EDSS) and timed 25-foot walk values (T25FW)., Results: Using a case-control methodology, we found significantly increased EDSS (p < 0.001) and T25FW (p = 0.01) in the EMS-MS group compared to the MS group. More patients in the EMS-MS group had histories of smoking, anxiety, depression, and headaches, while more patients in the MS group had histories of fatigue and neuropathic pain., Conclusion: When controlling for age, race, and MS therapy, those with EMS-MS experience more MS disability than controls, suggesting this population requires more monitoring and efficacious treatment., Competing Interests: Declaration of Competing Interest A. Balshi reports no disclosures relative to the manuscript; N. Manning reports no disclosures relative to the manuscript; J. Dempsey reports no disclosures relative to the manuscript; C. Jun reports no disclosures relative to the manuscript; U. Baber reports no disclosures relative to the manuscript; J.A. Sloane has grant funding from National MS Society and has consulted for Biogen, Genentech, Teva, Banner, Sanofi, and Cellgene., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Paramagnetic rim white matter (WM) lesions (PRL) are thought to be a main driver of non-relapsing multiple sclerosis (MS) progression. It is unknown whether cerebrospinal fluid (CSF)-soluble factors diffusing from the ventricles contribute to PRL formation., Objective: To investigate the distribution of PRL and non-rim brain WM lesions as a function of distance from ventricular CSF, their relationship with cortical lesions, the contribution of lesion phenotype, and localization to neurological disability., Methods: Lesion count and volume of PRL, non-rim WM, leukocortical lesion (LCL), and subpial/intracortical lesions were obtained at 7-T. The brain WM was divided into 1-mm-thick concentric rings radiating from the ventricles to extract PRL and non-rim WM lesion volume from each ring., Results: In total, 61 MS patients with ⩾1 PRL were included in the study. Both PRL and non-rim WM lesion volumes were the highest in the periventricular WM and declined with increasing distance from ventricles. A CSF distance-independent association was found between non-rim WM lesions, PRL, and LCL, but not subpial/intracortical lesions. Periventricular non-rim WM lesion volume was the strongest predictor of neurological disability., Conclusions: Non-rim and PRL share a gradient of distribution from the ventricles toward the cortex, suggesting that CSF proximity equally impacts the prevalence of both lesion phenotypes., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: C.A.T. has received research support from Genentech/Roche; E.H. has received research support by the NMSS fellowship FG-1507-05459; J.A.S. has consulted for Novartis, Biogen, Cellgene, and Genentech and received research support from Genentech/Roche; C.M. has received research support from Genentech/Roche. The remaining authors have nothing to disclose.

Background: Obesity and lower vitamin D levels are associated with adverse outcomes in multiple sclerosis (MS). Bariatric surgery is a safe intervention in patients with MS, although it lowers vitamin D levels in the general population., Objective: To investigate the effects of bariatric surgery on vitamin D levels and interrogate risk factors for unsuccessful post-operative weight loss in patients with MS., Methods: We retrospectively identified patients with MS who underwent bariatric surgery from 2001 to 2023. Wilcoxon signed rank tests for paired samples were used to compare pre- and post-operative body mass index (BMI), expanded disability status scale (EDSS), timed 25-foot walk (T25FW), and median vitamin D values., Results: Following bariatric surgery, patients with MS had a decrease in BMI (mean percent total weight loss of 18.4 %, range 0-38 %, p < 0.001) and an increase in vitamin D values (mean increase of 23 ng/mL, range -4-32 ng/mL, p < 0.001), while no change in EDSS or T25FW was seen. Four out of 20 patients did not lose more than 5 % of their pre-operative BMI, all of whom had chronic pain syndromes and were on gabapentin., Conclusion: Healthy vitamin D levels are attainable following bariatric surgery in patients with MS., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Dimethyl fumarate (DMF) depletes CD8+ and CD4+ T cells, and cases of herpes zoster (HZ) in patients with multiple sclerosis (MS) on DMF have been documented., Objectives: To evaluate lymphocyte subsets in patients with MS who developed HZ on DMF (Tecfidera) compared to matched controls who did not develop HZ., Methods: We used linear mixed-effects models to test for differences in white blood cell count, lymphocyte percentage, absolute lymphocyte count, CD3+ percentage, absolute CD3+ count, CD4+ percentage, absolute CD4+ count, CD8+ percentage, absolute CD8+ count, and CD4+:CD8+ ratio over time in HZ and non-HZ groups., Results: Eighteen patients developed HZ while on DMF. The linear mixed-effects model for CD4+:CD8+ ratio showed a significant difference between the HZ and non-HZ groups ( p = 0.033). CD4+:CD8+ ratio decreased over time in the HZ group and increased over time in the non-HZ group., Conclusion: Patients with MS who develop HZ while on DMF have high CD4+:CD8+ ratios, suggesting an imbalance of CD4+ and CD8+ cells that may put a patient at risk for developing HZ while on DMF. This result emphasizes the need for lymphocyte subset monitoring (including CD4+:CD8+ ratios) on DMF, as well as vaccination prior to DMF initiation., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: J.A.S. has grant funding from the National MS Society and has consulted for Biogen, Genentech, Teva, Banner, Sanofi, and Cellgene. The remaining authors have no conflicts to declare.

Background: The in vivo relation between microglia activation and demyelination in multiple sclerosis is still unclear., Objective: We combined 11 C-PBR28 positron emission tomography and rapid estimation of myelin for diagnostic imaging (REMyDI) to characterize the relation between these pathological processes in a heterogeneous MS cohort., Methods: 11 C-PBR28 standardized uptake values normalized by a pseudo-reference region (SUVR) were used to measure activated microglia. A voxelwise analysis compared 11 C-PBR28 SUVR in the white matter of 38 MS patients and 16 matched healthy controls. The relative difference in SUVR served as a threshold to classify patients' lesioned, perilesional and normal-appearing white matter as active or inactive. REMyDI was acquired in 27 MS patients for assessing myelin content in active and inactive white matter and its relationship with SUVR. Finally, we investigated the contribution of radiological metrics to clinical outcomes., Results: 11 C-PBR28 SUVR were abnormally higher in several white matter areas in MS. Myelin content was lower in active compared to inactive corresponding white matter regions. An inverse correlation between SUVR and myelin content was found. Radiological metrics correlated with both neurological and cognitive impairment., Conclusion: our data suggest an inverse relation of microglia activation and myelination, particularly in perilesional white matter tissue., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

With unclear characteristics of post-infection and post-vaccination immunity, the multiple sclerosis community lacks evidence to guide patients on their continued coronavirus disease 2019 (COVID-19) infection risk. As disease modifying treatments all modulate the immune system, we expect their use to alter acquired immunity to COVID-19, but the specific impact of individual treatments is unclear. To address this, we analyzed the patient and COVID-19 specific characteristics associated with post-infection humoral immunity in 58 patients with central nervous system (CNS) demyelinating disorders in the Boston metropolitan area. Univariate analysis of variance was performed using Mann Whitney U test for continuous variables, and Chi Square or Fisher Exact test for nominal variables. Univariate and stepwise multivariate nominal logistic regression identified clinical characteristics associated with COVID-19 specific nucleocapsid IgG antibody formation post-infection. Our cohort demonstrated a 42% post-infection seropositive rate with a significantly higher rate observed with shorter duration between infection and antibody collection and use of natalizumab over no/other treatment. Use of anti-CD20 treatments compared to no/other treatment was associated with a significantly lower rate of seropositivity. However, only shorter duration between infection and antibody collection as well as use of no/other treatment compared to anti-CD20 treatment were found to be independently associated with increased likelihood of post-infection seropositivity. Additionally, we demonstrate durability of antibody response up to 9 months in a small subset of patients. Thus, our data supports that patients with CNS demyelinating disorders regardless of DMT are able to form a measurable antibody response after COVID-19 infection, and that patients on anti-CD20 treatments form less robust immunity after COVID-19 infection., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Money, Baber, Saart, Samaan and Sloane.)

Cortical demyelination occurs early in multiple sclerosis (MS) and relates to disease outcome. The brain cortex has endogenous propensity for remyelination as proven from histopathology study. In this study, we aimed at characterizing cortical microstructural abnormalities related to myelin content by applying a novel quantitative MRI technique in early MS. A combined myelin estimation (CME) cortical map was obtained from quantitative 7-Tesla (7T) T 2 * and T 1 acquisitions in 25 patients with early MS and 19 healthy volunteers. Cortical lesions in MS patients were classified based on their myelin content by comparison with CME values in healthy controls as demyelinated, partially demyelinated, or non-demyelinated. At follow-up, we registered changes in cortical lesions as increased, decreased, or stable CME. Vertex-wise analysis compared cortical CME in the normal-appearing cortex in 25 MS patients vs. 19 healthy controls at baseline and investigated longitudinal changes at 1 year in 10 MS patients. Measurements from the neurite orientation dispersion and density imaging (NODDI) diffusion model were obtained to account for cortical neurite/dendrite loss at baseline and follow-up. Finally, CME maps were correlated with clinical metrics. CME was overall low in cortical lesions ( p = 0.03) and several normal-appearing cortical areas ( p < 0.05) in the absence of NODDI abnormalities. Individual cortical lesion analysis revealed, however, heterogeneous CME patterns from extensive to partial or absent demyelination. At follow-up, CME overall decreased in cortical lesions and non-lesioned cortex, with few areas showing an increase ( p < 0.05). Cortical CME maps correlated with processing speed in several areas across the cortex. In conclusion, CME allows detection of cortical microstructural changes related to coexisting demyelination and remyelination since the early phases of MS, and shows to be more sensitive than NODDI and relates to cognitive performance., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Barletta, Herranz, Treaba, Mehndiratta, Ouellette, Mangeat, Granberg, Sloane, Klawiter, Cohen-Adad and Mainero.)

Background and Objectives: We sought to define the risk of severe coronavirus disease 2019 (COVID-19) infection requiring hospitalization in patients with CNS demyelinating diseases such as MS and the factors that increase the risk for severe infection to guide decisions regarding patient care during the COVID-19 pandemic., Methods: A pilot cohort of 91 patients with confirmed or suspected COVID-19 infection from the Northeastern United States was analyzed to characterize patient risk factors and factors associated with an increased severity of COVID-19 infection. Univariate analysis of variance was performed using the Mann-Whitney U test or analysis of variance for continuous variables and the χ 2 or Fisher exact test for nominal variables. Univariate and stepwise multivariate logistic regression identified clinical characteristics or symptoms associated with hospitalization., Results: Our cohort demonstrated a 27.5% hospitalization rate and a 4.4% case fatality rate. Performance on Timed 25-Foot Walk before COVID-19 infection, age, number of comorbidities, and presenting symptoms of nausea/vomiting and neurologic symptoms (e.g., paresthesia or weakness) were independent risk factors for hospitalization, whereas headache predicted a milder course without hospitalization. An absolute lymphocyte count was lower in hospitalized patients during COVID-19 infection. Use of disease-modifying therapy did not increase the risk of hospitalization but was associated with an increased need for respiratory support., Discussion: The case fatality and hospitalization rates in our cohort were similar to those found in MS and general population COVID-19 cohorts within the region. Hospitalization was associated with increased disability, age, and comorbidities but not disease-modifying therapy use., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Objective: This study aimed to investigate at 7.0-T MRI a) the role of multiple sclerosis (MS) cortical lesions in cortical tissue loss b) their relation to neurological disability., Methods: In 76 relapsing remitting and 26 secondary progressive MS patients (N = 102) and 56 healthy subjects 7.0-T T 2 * -weighted images were acquired for lesion segmentation; 3.0-T T 1 -weighted structural scans for cortical surface reconstruction/cortical thickness estimation. Patients were dichotomized based on the median cortical lesion volume in low and high cortical lesion load groups that differed by age, MS phenotype and degree of neurological disability. Group differences in cortical thickness were tested on reconstructed cortical surface. Patients were evaluated clinically by means of the Expanded Disability Status Scale (EDSS)., Results: Cortical lesions were detected in 96% of patients. White matter lesion load was greater in the high than in the low cortical lesion load MS group (p = 0.01). Both MS groups disclosed clusters (prevalently parietal) of cortical thinning relative to healthy subjects, though these regions did not show the highest cortical lesion density, which predominantly involved frontal regions. Cortical thickness decreased on average by 0.37 mm, (p = 0.002) in MS patients for each unit standard deviation change in white matter lesion volume. The odds of having a higher EDSS were associated with cortical lesion volume (1.78, p = 0.01) and disease duration (1.15, p < 0.001)., Conclusion: Cortical thinning in MS is not directly related to cortical lesion load but rather with white matter lesion volume. Neurological disability in MS is better explained by cortical lesion volume assessment.

In multiple sclerosis, individual lesion-type patterns on magnetic resonance imaging might be valuable for predicting clinical outcome and monitoring treatment effects. Neuropathological and imaging studies consistently show that cortical lesions contribute to disease progression. The presence of chronic active white matter lesions harbouring a paramagnetic rim on susceptibility-weighted magnetic resonance imaging has also been associated with an aggressive form of multiple sclerosis. It is, however, still uncertain how these two types of lesions relate to each other, or which one plays a greater role in disability progression. In this prospective, longitudinal study in 100 multiple sclerosis patients (74 relapsing-remitting, 26 secondary progressive), we used ultra-high field 7-T susceptibility imaging to characterize cortical and rim lesion presence and evolution. Clinical evaluations were obtained over a mean period of 3.2 years in 71 patients, 46 of which had a follow-up magnetic resonance imaging. At baseline, cortical and rim lesions were identified in 96% and 63% of patients, respectively. Rim lesion prevalence was similar across disease stages. Patients with rim lesions had higher cortical and overall white matter lesion load than subjects without rim lesions ( P  =   0.018-0.05). Altogether, cortical lesions increased by both count and volume (P = 0.004) over time, while rim lesions expanded their volume ( P  =   0.023) whilst lacking new rim lesions; rimless white matter lesions increased their count but decreased their volume ( P  =   0.016). We used a modern machine learning algorithm based on extreme gradient boosting techniques to assess the cumulative power as well as the individual importance of cortical and rim lesion types in predicting disease stage and disability progression, alongside with more traditional imaging markers. The most influential imaging features that discriminated between multiple sclerosis stages (area under the curve±standard deviation = 0.82 ± 0.08) included, as expected, the normalized white matter and thalamic volume, white matter lesion volume, but also leukocortical lesion volume. Subarachnoid cerebrospinal fluid and leukocortical lesion volumes, along with rim lesion volume were the most important predictors of Expanded Disability Status Scale progression (area under the curve±standard deviation = 0.69 ± 0.12). Taken together, these results indicate that while cortical lesions are extremely frequent in multiple sclerosis, rim lesion development occurs only in a subset of patients. Both, however, persist over time and relate to disease progression. Their combined assessment is needed to improve the ability of identifying multiple sclerosis patients at risk of progressing disease., (© The Author(s) (2021). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Thalamic pathology is a marker for neurodegeneration and multiple sclerosis (MS) disease progression., Objective: To characterize (1) the morphology of thalamic lesions, (2) their relation to cortical and white matter (WM) lesions, and (3) clinical measures, and to assess (4) the imaging correlates of thalamic atrophy., Methods: A total of 90 MS patients and 44 healthy controls underwent acquisition of 7 Tesla images for lesion segmentation and 3 Tesla scans for atrophy evaluation. Thalamic lesions were classified according to the shape and the presence of a central venule. Regression analysis identified the predictors of (1) thalamic atrophy, (2) neurological disability, and (3) information processing speed., Results: Thalamic lesions were mostly ovoid than periventricular, and for the great majority (78%) displayed a central venule. Lesion volume in the thalamus, cortex, and WM did not correlate with each other. Thalamic atrophy was only associated with WM lesion volume ( p  = 0.002); subpial and WM lesion volumes were associated with neurological disability ( p  = 0.016; p  < 0.001); and WM and thalamic lesion volumes were related with cognitive impairment ( p  < 0.001; p  = 0.03)., Conclusion: Thalamic lesions are unrelated to those in the cortex and WM, suggesting that they may not share common pathogenic mechanisms and do not contribute to thalamic atrophy. Combined WM, subpial, and thalamic lesion volumes at 7 Tesla contribute to the disease severity.

Cladribine tablets 10 mg (3.5 mg/kg cumulative dose over 2 years) are approved for the treatment of relapsing forms of multiple sclerosis (MS), including relapsing-remitting MS and active secondary progressive MS. However, real-world data on cladribine tablets are limited. CLICK-MS and MASTER-2 are single arm, observational, 30-month, Phase IV studies in the US evaluating the effectiveness and safety of cladribine tablets 3.5 mg/kg in patients with relapsing-remitting MS or active secondary progressive MS who had suboptimal response to prior injectable (CLICK-MS), or infusion/oral (MASTER-2) disease-modifying therapy. The primary end point is 24-month annualized relapse rate. Key secondary end points include patient-reported outcomes on quality of life measures, treatment adherence and adverse events. Studies began in 2019 and are expected to be completed in 2023. Trial registration number • CLICK-MS: NCT03933215 (ClinicalTrials.gov) Full title ; CL adribine tablets: observational evaluation of effect I veness and patient-reported outcomes in suboptimally C ontrolled patients previously ta K ing injectable disease-modifying drugs for relapsing forms of M ultiple S clerosis • MASTER-2: NCT03933202 (ClinicalTrials.gov) Full title ; Cladribine tablets: observational evaluation of effectiveness and patient-reported outcomes in subopti MA lly controlled patient S previously T aking oral or infusion dis E ase-modifying d R ugs for relapsing forms of multiple sclerosis.

Background: Patients with a compromised immune system are at risk for converting from latent tuberculosis infection (LTBI) to active tuberculosis (TB) infection. Multiple sclerosis (MS) therapies may put individuals with LTBI at higher risk of TB., Methods: Patients at the Beth Israel Deaconess Medical Center MS Clinic were screened for TB as part of routine testing with the QuantiFERON-TB Gold In-Tube (QFT-GIT) assay (Cellestis Ltd) from 2013 to 2017. Patients were tested either before or during immunomodulatory therapy., Results: Four of 222 patients (1.8%; 95% CI, 0.1%-3.6%) had positive QFT-GIT results; three patients had risk factors for TB, having emigrated from TB-endemic countries or worked in the health care industry. Twenty-eight of 222 patients (12.6%) had an indeterminate assay result, and 75.0% of these occurred in patients taking dimethyl fumarate. Fingolimod, natalizumab, or anti-CD20 treatments showed 0% to 7.7% indeterminate results., Conclusions: The prevalence of LTBI was 1.8% in the Beth Israel Deaconess Medical Center MS Clinic. Not all LTBI cases were associated with known risk factors for TB. Screening for LTBI before starting immunosuppressive agents for MS could help prevent activation of TB. Dimethyl fumarate use is associated with indeterminate QFT-GIT results, possibly due to functional effects on lymphocytes and levels of cytokines, such as interferon gamma. In contrast, fingolimod use was rarely associated with indeterminate QFT-GIT results despite a high rate of lymphopenia in virtually all patients., Competing Interests: Financial Disclosures: Dr Sloane has served as a consultant for Biogen, Serono/Merck, Celgene, Genzyme, Genentech, and Teva. The other authors declare no conflicts of interest., (© 2021 Consortium of Multiple Sclerosis Centers.)

Background: Studies linking MRI findings in MS patients with obstructive sleep apnea severity are limited., Objective: We conducted a retrospective study to assess MRI abnormalities associated with obstructive sleep apnea (OSA) in patients with multiple sclerosis (MS)., Methods: We performed retrospective chart review of 65 patients with multiple sclerosis who had undergone polysomnography (PSG) for fatigue as well as brain MRI. We measured the number of lesions in the brainstem and calculated the standardized third ventricular width (sTVW) as a measure of brain atrophy, and subsequently performed correlation analyses of the apnea-hypopnea index (AHI) with brainstem lesion location, sTVW, and Expanded Disability Status Scale (EDSS)., Results: MS Patients with OSA were significantly older and had a higher body mass index (BMI) and higher AHI measures than patients without OSA. After adjustment for covariates, significant associations were found between AHI and lesion burden in the midbrain (p < 0.01) and pons (p = 0.05), but not medulla., Conclusions: Midbrain and pontine lesions burden correlated with AHI, suggesting MS lesion location could contribute to development of OSA., Competing Interests: Conflict of Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Sloane served of advisory boards for Biogen, Genentech, Celgene, EMD Serono, Genzyme. Other authors have no disclosures., (© The Author(s) 2020.)

Background and Purpose: Meningeal inflammation is implicated in cortical demyelination and disability progression in multiple sclerosis (MS). Gadolinium (Gd)-enhanced 3-dimensional (3D) FLAIR (fluid-attenuated inversion recovery) magnetic resonance imaging (MRI) can identify leptomeningeal enhancement (LME) in MS. Further characterization is needed to determine if LME is an imaging biomarker for meningeal inflammation. We sought to characterize the natural history of LME in the community setting, including persistence/resolution, effect of disease-modifying therapy, scanner variability, timing of acquisition, and imaging pitfalls that may lead to misinterpretation., Methods: A total of 341 MRI exams with Gd-enhanced 3D-FLAIR were reviewed in MS and non-MS patients to determine frequency of enhancement by MS subtype and association with therapy. A phantom was used to assess scanner variability. Two MS patients with seven LME were imaged at four postinjection time points to generate time-intensity curves. Imaging pitfalls were compiled., Results: A total of 16.6% (40/241) of MS patients revealed LME compared to 8% (8/100) in non-MS patients (P = .04). There was no association with MS subtype, therapy, or disease activity. Detection using General Electric's version of 3D-FLAIR (29%) was greater than with Siemen's 3D-FLAIR (12%) at 1.5T (Tesla) (P < .001). Lesions were generally stable but resolved in 2 patients following high-dose steroids. LME kinetics were heterogeneous, even within patients, without uniform optimal time for acquisition. Enhancement curves exhibited three different variations, similar to the two-compartment model. Imaging pitfalls included enhancements of uncertain biologic significance, cortical veins and anatomic structures, and imaging artifacts., Conclusions: Awareness of LME characteristics, variability with imaging parameters, and imaging pitfalls will facilitate determining the potential role as an imaging biomarker for meningeal inflammation., (© 2020 American Society of Neuroimaging.)

The outbreak of a severe acute respiratory syndrome caused by a novel coronavirus (COVID-19), has raised health concerns for patients with multiple sclerosis (MS) who are commonly on long-term immunotherapies. Managing MS during the pandemic remains challenging with little published experience and no evidence-based guidelines. We present five teriflunomide-treated patients with MS who subsequently developed active COVID-19 infection. The patients continued teriflunomide therapy and had self-limiting infection, without relapse of their MS. These observations have implications for the management of MS in the setting of the COVID-19 pandemic.

Background: Neuroinflammation with microglia activation is thought to be closely related to cortical multiple sclerosis (MS) lesion pathogenesis., Objective: Using 11 C-PBR28 and 7 Tesla (7T) imaging, we assessed in 9 relapsing-remitting multiple sclerosis (RRMS) and 10 secondary progressive multiple sclerosis (SPMS) patients the following: (1) microglia activation in lesioned and normal-appearing cortex, (2) cortical lesion inflammatory profiles, and (3) the relationship between neuroinflammation and cortical integrity., Methods: Mean 11 C-PBR28 uptake was measured in focal cortical lesions, cortical areas with 7T quantitative T 2 * (q-T 2 *) abnormalities, and normal-appearing cortex. The relative difference in cortical 11 C-PBR28 uptake between patients and 14 controls was used to classify cortical lesions as either active or inactive. Disease burden was investigated according to cortical lesion inflammatory profiles. The relation between q-T 2 * and 11 C-PBR28 uptake along the cortex was assessed., Results: 11 C-PBR28 uptake was abnormally high in cortical lesions in RRMS and SPMS; in SPMS, tracer uptake was significantly increased also in normal-appearing cortex. 11 C-PBR28 uptake and q-T 2 * correlated positively in many cortical areas, negatively in some regions. Patients with high cortical lesion inflammation had worse clinical outcome and higher intracortical lesion burden than patients with low inflammation., Conclusion: 11 C-PBR28 and 7T imaging reveal distinct profiles of cortical inflammation in MS, which are related to disease burden.

We used 7 T MRI to: (i) characterize the grey and white matter pathology in the cervical spinal cord of patients with early relapsing-remitting and secondary progressive multiple sclerosis; (ii) assess the spinal cord lesion spatial distribution and the hypothesis of an outside-in pathological process possibly driven by CSF-mediated immune cytotoxic factors; and (iii) evaluate the association of spinal cord pathology with brain burden and its contribution to neurological disability. We prospectively recruited 20 relapsing-remitting, 15 secondary progressive multiple sclerosis participants and 11 age-matched healthy control subjects to undergo 7 T imaging of the cervical spinal cord and brain as well as conventional 3 T brain acquisition. Cervical spinal cord imaging at 7 T was used to segment grey and white matter, including lesions therein. Brain imaging at 7 T was used to segment cortical and white matter lesions and 3 T imaging for cortical thickness estimation. Cervical spinal cord lesions were mapped voxel-wise as a function of distance from the inner central canal CSF pool to the outer subpial surface. Similarly, brain white matter lesions were mapped voxel-wise as a function of distance from the ventricular system. Subjects with relapsing-remitting multiple sclerosis showed a greater predominance of spinal cord lesions nearer the outer subpial surface compared to secondary progressive cases. Inversely, secondary progressive participants presented with more centrally located lesions. Within the brain, there was a strong gradient of lesion formation nearest the ventricular system that was most evident in participants with secondary progressive multiple sclerosis. Lesion fractions within the spinal cord grey and white matter were related to the lesion fraction in cerebral white matter. Cortical thinning was the primary determinant of the Expanded Disability Status Scale, white matter lesion fractions in the spinal cord and brain of the 9-Hole Peg Test and cortical thickness and spinal cord grey matter cross-sectional area of the Timed 25-Foot Walk. Spinal cord lesions were localized nearest the subpial surfaces for those with relapsing-remitting and the central canal CSF surface in progressive disease, possibly implying CSF-mediated pathogenic mechanisms in lesion development that may differ between multiple sclerosis subtypes. These findings show that spinal cord lesions involve both grey and white matter from the early multiple sclerosis stages and occur mostly independent from brain pathology. Despite the prevalence of cervical spinal cord lesions and atrophy, brain pathology seems more strongly related to physical disability as measured by the Expanded Disability Status Scale., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Unfortunately, the given name and family name of first author was incorrectly tagged in the xml data, therefore it is abbreviated wrongly as "Morales FS" in Pubmed. The correct given name is Fabian and family name is Sierra Morales. Auhtor name should be abbreviated as Sierra Morales F.

Objectives: To identify risk factors for DMF-induced lymphopenia and characterize its impact on T lymphocyte subsets in MS patients., Methods: We performed a retrospective analysis of 194 RRMS patients treated with DMF at the Beth Israel Deaconess Medical Center (BIDMC) over a median of 17 months. We reviewed demographics, ethnic background, prior medication history, complete blood counts and T lymphocyte subsets. Possible lymphopenia risk factors examined included age, prior natalizumab exposure, vitamin D levels, and concomitant exposure to carbamazepine, opiates, tobacco, or steroids. Lymphopenia was defined as grade 1: absolute lymphocytes count (ALC) 800-999/μl; grade 2: ALC 500-799/μl; grade 3: ALC 200-499/μl; and grade 4: ALC < 200/μl., Results: Of 194 DMF-treated patients, 73 (38%) developed lymphopenia and reached an ALC nadir after a median of 504 days (range 82-932). Risk of developing DMF-induced lymphopenia increased with BMI 25-30, older age, white ethnicity, non-smoking status, and lowest quartile baseline ALC. Prior exposure to natalizumab or concomitant steroid, opiates or carbamazepine/oxcarbamazepine use was not associated with lymphopenia. Compared to baseline levels, CD8 T cells were significantly more reduced than CD4 cells. CD8 counts were more commonly reduced with age or white ethnicity. Subjects with BMI 25-30 was associated with a higher risk of abnormal CD4 cell count reductions. In contrast, non-smokers were more likely to experience reductions in both CD4 and CD8 counts while on DMF., Conclusions: Patients with low baseline lymphocyte counts, with intermediate BMI, with white ethnicity, with advanced age, or with no tobacco use, had a significantly higher incidence of lymphopenia on DMF. Intermediate BMI or lowest quartile baseline ALC predicted low CD4 levels, while advanced age or white ethnicity predicted low CD8 levels from DMF exposure.

Background Cortical lesions develop early in multiple sclerosis (MS) and play a major role in disease progression. MRI at 7.0 T shows high sensitivity for detection of cortical lesions as well as better spatial resolution and signal-to-noise ratio compared with lower field strengths. Purpose To longitudinally characterize (a) the development and evolution of cortical lesions in multiple sclerosis across the cortical width, sulci, and gyri; (b) their relation with white matter lesion accrual; and (c) the contribution of 7.0-T cortical and white matter lesion load and cortical thickness to neurologic disability. Materials and Methods Twenty participants with relapsing-remitting MS and 13 with secondary progressive MS, along with 10 age-matched healthy controls, were prospectively recruited from 2010 to 2016 to acquire, in two imaging sessions (mean interval, 1.5 years), 7.0-T MRI T2*-weighted gradient-echo images (0.33 × 0.33 × 1.0 mm 3 ) for cortical and white matter lesion segmentation and 3.0-T T1-weighted images for cortical surface reconstruction and cortical thickness estimation. Cortical lesions were sampled through the cortex to quantify cortical lesion distribution. The Expanded Disability Status Scale (EDSS) was used to assess neurologic disability. Nonparametric statistics assessed differences between and within groups in MRI metrics of cortical and white matter lesion burden; regression analysis explored associations of disability with MRI metrics. Results Twenty-five of 31 (81%) participants developed new cortical lesions per year (intracortical, 1.3 ± 1.7 vs leukocortical, 0.7 ± 1.9; P = .04), surpassing white matter lesion accrual (cortical, 2.0 ± 2.8 vs white matter, 0.7 ± 0.6; P = .01). In contrast to white matter lesions, cortical lesion accrual was greater in participants with secondary progressive MS than with relapsing-remitting MS (3.6 lesions/year ± 4.2 vs 1.1 lesions/year ± 0.9, respectively; P = .03) and preferentially localized in sulci. Total cortical lesion volume independently predicted baseline EDSS (β = 1.5, P < .001) and EDSS changes at follow-up (β = 0.5, P = .003). Conclusion Cortical lesions predominantly develop intracortically and within sulci, suggesting an inflammatory cerebrospinal fluid-mediated lesion pathogenesis. Cortical lesion accumulation was prominent at 7.0 T and independently predicted neurologic disability progression. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Filippi and Rocca in this issue.

Background: Thalamic degeneration impacts multiple sclerosis (MS) prognosis., Objective: To investigate heterogeneous thalamic pathology, its correlation with white matter (WM), cortical lesions and thickness, and as function of distance from cerebrospinal fluid (CSF)., Methods: In 41 MS subjects and 17 controls, using 3 and 7 T imaging, we tested for (1) differences in thalamic volume and quantitative T 2 * (q-T 2 *) (2) globally and (3) within concentric bands originating from the CSF/thalamus interface; (4) the relation between thalamic, cortical, and WM metrics; and (5) the contribution of magnetic resonance imaging (MRI) metrics to clinical scores. We also assessed MS thalamic lesion distribution as a function of distance from CSF., Results: Thalamic lesions were mainly located next to the ventricles. Thalamic volume was decreased in MS versus controls ( p < 10 -2 ); global q-T 2 * was longer in secondary progressive multiple sclerosis (SPMS) only ( p < 10 -2 ), indicating myelin and/or iron loss. Thalamic atrophy and longer q-T 2 * correlated with WM lesion volume ( p < 0.01). In relapsing-remitting MS, q-T 2 * thalamic abnormalities were located next to the WM ( p < 0.01 (uncorrected), p = 0.09 (corrected)), while they were homogeneously distributed in SPMS. Cortical MRI metrics were the strongest predictors of clinical outcome., Conclusion: Heterogeneous pathological processes affect the thalamus in MS. While focal lesions are likely mainly driven by CSF-mediated factors, overall thalamic degeneration develops in association with WM lesions.

Rituximab, a monoclonal antibody to CD20, is an effective treatment for relapsing remitting multiple sclerosis (MS) reducing relapse rate by at least 50% over time. Although the mechanism for this clinical benefit is unclear, rituximab depletes circulating B cells, which can perform antigen presentation and stimulation of T cells. Another anti-CD20 drug, ocrelizumab, has recently been FDA approved to treat both relapsing remitting and progressive forms of MS. While long-term effects of ocrelizumab use are essentially unknown, long-term use of rituximab has been associated with the development of progressive multifocal leukoencephalopathy (PML) at an incidence of approximately 1/25,000 in non-MS conditions. Serostatus for JC virus (JCV), the causative agent for PML, is an important risk stratification tool for natalizumab, but its utility in other MS treatments is uncertain. We found that rituximab use was associated with a reduction in JCV antibody index values in MS patients. Reductions in immunoglobulins, IgM in particular, are seen in concert with JCV antibody reductions. Physicians should exercise caution when using JCV antibody indices to assess any risk of PML for patients on rituximab.

The aim of this study was to investigate the interplay between structural connectivity and cortical demyelination in early multiple sclerosis. About 27 multiple sclerosis patients and 18 age-matched controls underwent two MRI scanning sessions. The first was done at 7T and involved acquiring quantitative T 1 and T 2 * high-resolution maps to estimate cortical myelination. The second was done on a Connectom scanner and consisted of acquiring high angular resolution diffusion-weighted images to compute white matter structural connectivity metrics: strength, clustering and local efficiency. To further investigate the interplay between structural connectivity and cortical demyelination, patients were divided into four groups according to disease-duration: 0-1 year, 1-2 years, 2-3 years, and >3 years. ANOVA and Spearman's correlations were used to highlight relations between metrics. ANOVA detected a significant effect between disease duration and both cortical myelin (p = 2 × 10 -8 ) and connectivity metrics (p < 10 -4 ). We observed significant cortical myelin loss in the shorter disease-duration cohorts (0-1 year, p = .0015), and an increase in connectivity in the longer disease-duration cohort (2-3 years, strength: p = .01, local efficiency: p = .002, clustering: p = .001). Moreover, significant covariations between myelin estimation and white matter connectivity metrics were observed: Spearman's Rho correlation coefficients of 0.52 (p = .0003), 0.55 (p = .0001), and 0.53 (p = .0001) for strength, local efficiency, and clustering, respectively. An association between cortical myelin loss and changes in white matter connectivity in early multiple sclerosis was detected. These changes in network organization might be the result of compensatory mechanisms in response to the ongoing cortical diffuse damage in the early stages of multiple sclerosis., (© 2018 Wiley Periodicals, Inc.)

Neuroaxonal pathology is a main determinant of disease progression in multiple sclerosis; however, its underlying pathophysiological mechanisms, including its link to inflammatory demyelination and temporal occurrence in the disease course are still unknown. We used ultra-high field (7 T), ultra-high gradient strength diffusion and T1/T2-weighted myelin-sensitive magnetic resonance imaging to characterize microstructural changes in myelin and neuroaxonal integrity in the cortex and white matter in early stage multiple sclerosis, their distribution in lesional and normal-appearing tissue, and their correlations with neurological disability. Twenty-six early stage multiple sclerosis subjects (disease duration ≤5 years) and 24 age-matched healthy controls underwent 7 T T2*-weighted imaging for cortical lesion segmentation and 3 T T1/T2-weighted myelin-sensitive imaging and neurite orientation dispersion and density imaging for assessing microstructural myelin, axonal and dendrite integrity in lesional and normal-appearing tissue of the cortex and the white matter. Conventional mean diffusivity and fractional anisotropy metrics were also assessed for comparison. Cortical lesions were identified in 92% of early multiple sclerosis subjects and they were characterized by lower intracellular volume fraction (P = 0.015 by paired t-test), lower myelin-sensitive contrast (P = 0.030 by related-samples Wilcoxon signed-rank test) and higher mean diffusivity (P = 0.022 by related-samples Wilcoxon signed-rank test) relative to the contralateral normal-appearing cortex. Similar findings were observed in white matter lesions relative to normal-appearing white matter (all P < 0.001), accompanied by an increased orientation dispersion (P < 0.001 by paired t-test) and lower fractional anisotropy (P < 0.001 by related-samples Wilcoxon signed-rank test) suggestive of less coherent underlying fibre orientation. Additionally, the normal-appearing white matter in multiple sclerosis subjects had diffusely lower intracellular volume fractions than the white matter in controls (P = 0.029 by unpaired t-test). Cortical thickness did not differ significantly between multiple sclerosis subjects and controls. Higher orientation dispersion in the left primary motor-somatosensory cortex was associated with increased Expanded Disability Status Scale scores in surface-based general linear modelling (P < 0.05). Microstructural pathology was frequent in early multiple sclerosis, and present mainly focally in cortical lesions, whereas more diffusely in white matter. These results suggest early demyelination with loss of cells and/or cell volumes in cortical and white matter lesions, with additional axonal dispersion in white matter lesions. In the cortex, focal lesion changes might precede diffuse atrophy with cortical thinning. Findings in the normal-appearing white matter reveal early axonal pathology outside inflammatory demyelinating lesions., (© The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

We present the case of an HIV-2-infected patient who developed progressive multifocal leukoencephalopathy (PML) in the setting of immune reconstitution inflammatory syndrome (IRIS) presenting as Bell's palsy. The brain MRI showed a single lesion in the facial colliculus considered initially to be ischemic in nature. This case report should alert clinicians that PML can occur in the setting of HIV-2 infection. It also illustrates the difficulty of establishing the diagnosis of PML.

Using quantitative T 2 * at 7 Tesla (T) magnetic resonance imaging, we investigated whether impairment in selective cognitive functions in multiple sclerosis (MS) can be explained by pathology in specific areas and/or layers of the cortex. Thirty-one MS patients underwent neuropsychological evaluation, acquisition of 7 T multi-echo T 2 * gradient-echo sequences, and 3 T anatomical images for cortical surfaces reconstruction. Seventeen age-matched healthy subjects served as controls. Cortical T 2 * maps were sampled at various depths throughout the cortex and juxtacortex. Relation between T 2 *, neuropsychological scores and a cognitive index (CI), calculated from a principal component analysis on the whole battery, was tested by a general linear model. Cognitive impairment correlated with T 2 * increase, independently from white matter lesions and cortical thickness, in cortical areas highly relevant for cognition belonging to the default-mode network (p < 0.05 corrected). Dysfunction in different cognitive functions correlated with longer T 2 * in selective cortical regions, most of which showed longer T 2 * relative to controls. For most tests, this association was strongest in deeper cortical layers. Executive dysfunction, however, was mainly related with pathology in juxtameningeal cortex. T 2 * explained up to 20% of the variance of the CI, independently of conventional imaging metrics (adjusted-R 2 : 52-67%, p < 5.10 - 4 ). Location of pathology across the cortical width and mantle showed selective correlation with impairment in differing cognitive domains. These findings may guide studies at lower field strength designed to develop surrogate markers of cognitive impairment in MS.

Objective: In multiple sclerosis (MS), using simultaneous magnetic resonance-positron emission tomography (MR-PET) imaging with 11 C-PBR28, we quantified expression of the 18kDa translocator protein (TSPO), a marker of activated microglia/macrophages, in cortex, cortical lesions, deep gray matter (GM), white matter (WM) lesions, and normal-appearing WM (NAWM) to investigate the in vivo pathological and clinical relevance of neuroinflammation., Methods: Fifteen secondary-progressive MS (SPMS) patients, 12 relapsing-remitting MS (RRMS) patients, and 14 matched healthy controls underwent 11 C-PBR28 MR-PET. MS subjects underwent 7T T2*-weighted imaging for cortical lesion segmentation, and neurological and cognitive evaluation. 11 C-PBR28 binding was measured using normalized 60- to 90-minute standardized uptake values and volume of distribution ratios., Results: Relative to controls, MS subjects exhibited abnormally high 11 C-PBR28 binding across the brain, the greatest increases being in cortex and cortical lesions, thalamus, hippocampus, and NAWM. MS WM lesions showed relatively modest TSPO increases. With the exception of cortical lesions, where TSPO expression was similar, 11 C-PBR28 uptake across the brain was greater in SPMS than in RRMS. In MS, increased 11 C-PBR28 binding in cortex, deep GM, and NAWM correlated with neurological disability and impaired cognitive performance; cortical thinning correlated with increased thalamic TSPO levels., Interpretation: In MS, neuroinflammation is present in the cortex, cortical lesions, deep GM, and NAWM, is closely linked to poor clinical outcome, and is at least partly linked to neurodegeneration. Distinct inflammatory-mediated factors may underlie accumulation of cortical and WM lesions. Quantification of TSPO levels in MS could prove to be a sensitive tool for evaluating in vivo the inflammatory component of GM pathology, particularly in cortical lesions. Ann Neurol 2016;80:776-790., (© 2016 American Neurological Association.)

Risk of relapse after natalizumab (NAT) cessation and switch to dimethyl fumarate (DMF) is unknown. The objective of this paper is to identify the risk and associated risk factors for relapse after switching from NAT to DMF in relapsing-remitting multiple sclerosis. Patients (n = 30) were treated with NAT for ≥12 months and then switched to DMF in a mean of 50 days. Patient age, annualized relapse rates (ARR), Expanded Disability Status Scale scores (EDSS), and lymphocyte counts were assessed. Overall, eight patients (27 %) had relapses after switching to DMF. Five patients (17 %) suffered severe relapses with multifocal clinical and radiological findings. New lesions by MRI (T2 hyperintense or enhancing) were observed in 35 % of patients. Relapses occurred at a mean of 3.5 months after NAT cessation. Patient age and elevated ARR prior to NAT use were significantly associated with risk of relapse after switch to DMF. Once on DMF for 4 months prior to relapse, lymphocyte count decreased more significantly in patients without relapses than those with relapses. Switching from NAT to DMF correlated with increased relapses. Young patient age, high ARR and stability of lymphocyte counts were risk factors for relapse after transition from NAT to DMF.

Purpose: To investigate in vivo the spatial specificity of the interdependence between intracortical and white matter (WM) pathologic changes as function of cortical depth and distance from the cortex in multiple sclerosis (MS), and their independent contribution to physical and cognitive disability., Materials and Methods: This study was institutional review board-approved and participants gave written informed consent. In 34 MS patients and 17 age-matched control participants, 7-T quantitative T2* maps, 3-T T1-weighted anatomic images for cortical surface reconstruction, and 3-T diffusion tensor images (DTI) were obtained. Cortical quantitative T2* maps were sampled at 25%, 50%, 75% depth from pial surface. Tracts of interest were reconstructed by using probabilistic tractography. The relationship between DTI metrics voxelwise of the tracts and cortical integrity in the projection cortex was tested by using multilinear regression models., Results: In MS, DTI abnormal findings along tracts correlated with quantitative T2* changes (suggestive of iron and myelin loss) at each depth of the cortical projection area (P < .01, corrected). This association, however, was not spatially specific because abnormal findings in WM tracts also related to cortical pathologic changes outside of the projection cortex of the tract (P < .001). Expanded Disability Status Scale pyramidal score was predicted by axial diffusivity along the corticospinal tract (β = 4.6 × 10(3); P < .001), Symbol Digit Modalities Test score by radial diffusivity along the cingulum (β = -4.3 × 10(4); P < .01), and T2* in the cingulum cortical projection at 25% depth (β = -1.7; P < .05)., Conclusion: Intracortical and WM injury are concomitant pathologic processes in MS, which are not uniquely distributed according to a tract-cortex-specific pattern; their association may reflect a common stage-dependent mechanism., (© RSNA, 2015.)

Objectives: Using quantitative T2* 7-tesla (7T) MRI as a marker of demyelination and iron loss, we investigated, in patients with relapsing-remitting multiple sclerosis (RRMS) and secondary progressive multiple sclerosis (SPMS), spatial and tissue intrinsic characteristics of cortical lesion(s) (CL) types, and structural integrity of perilesional normal-appearing cortical gray matter (NACGM) as a function of distance from lesions., Methods: Patients with MS (18 RRMS, 11 SPMS), showing at least 2 CL, underwent 7T T2* imaging to obtain (1) magnitude images for segmenting focal intracortical lesion(s) (ICL) and leukocortical lesion(s) (LCL), and (2) cortical T2* maps. Anatomical scans were collected at 3T for cortical surface reconstruction using FreeSurfer. Seventeen age-matched healthy participants served as controls., Results: ICL were predominantly located in sulci of frontal, parietal, and cingulate cortex; LCL distribution was more random. In MS, T2* was higher in both ICL and LCL, indicating myelin and iron loss, than in NACGM (p < 0.00003) irrespective of CL subtype and MS phenotype. T2* was increased in perilesional cortex, tapering away from CL toward NACGM, the wider changes being for LCL in SPMS. NACGM T2* was higher in SPMS relative to RRMS (p = 0.006) and healthy cortex (p = 0.02)., Conclusions: CL had the same degree of demyelination and iron loss regardless of lesion subtype and disease stage. Cortical damage expanded beyond visible CL, close to lesions in RRMS, and more diffusely in SPMS. Evaluation of NACGM integrity, beyond focal CL, could represent a surrogate marker of MS progression., (© 2015 American Academy of Neurology.)

Objective: To determine the prevalence of JC virus (JCV) reactivation and JCV-specific cellular immune response during prolonged natalizumab treatment for multiple sclerosis (MS)., Methods: We enrolled 43 JCV-seropositive MS patients, including 32 on natalizumab monotherapy >18 months, 6 on interferon β-1a monotherapy >36 months, and 5 untreated controls. We performed quantitative real-time polymerase chain reaction in cerebrospinal fluid (CSF), blood, and urine for JCV DNA, and we determined JCV-specific T-cell responses using enzyme-linked immunosorbent spot (ELISpot) and intracellular cytokine staining (ICS) assays, ex vivo and after in vitro stimulation with JCV peptides., Results: JCV DNA was detected in the CSF of 2 of 27 (7.4%) natalizumab-treated MS patients who had no symptoms or magnetic resonance imaging-detected lesions consistent with progressive multifocal leukoencephalopathy. JCV DNA was detected in blood of 12 of 43 (27.9%) and in urine of 11 of 43 (25.6%) subjects without a difference between natalizumab-treated patients and controls. JC viral load was higher in CD34(+) cells and in monocytes compared to other subpopulations. ICS was more sensitive than ELISpot. JCV-specific T-cell responses, mediated by both CD4(+) and CD8(+) T lymphocytes, were detected more frequently after in vitro stimulation. JCV-specific CD4(+) T cells were detected ex vivo more frequently in MS patients with JCV DNA in CD34(+) (p = 0.05) and B cells (p = 0.03)., Interpretation: Asymptomatic JCV reactivation may occur in CSF of natalizumab-treated MS patients. JCV DNA load is higher in circulating CD34(+) cells and monocytes compared to other mononuclear cells, and JCV in blood might trigger a JCV-specific CD4(+) T-cell response. JCV-specific cellular immune response is highly prevalent in all JCV-seropositive MS patients, regardless of treatment., (© 2014 American Neurological Association.)

We have previously shown that myelin abnormalities characterize the normal aging process of the brain and that an age-associated reduction in Klotho is conserved across species. Predominantly generated in brain and kidney, Klotho overexpression extends life span, whereas loss of Klotho accelerates the development of aging-like phenotypes. Although the function of Klotho in brain is unknown, loss of Klotho expression leads to cognitive deficits. We found significant effects of Klotho on oligodendrocyte functions, including induced maturation of rat primary oligodendrocytic progenitor cells (OPCs) in vitro and myelination. Phosphoprotein analysis indicated that Klotho's downstream effects involve Akt and ERK signal pathways. Klotho increased OPC maturation, and inhibition of Akt or ERK function blocked this effect on OPCs. In vivo studies of Klotho knock-out mice and control littermates revealed that knock-out mice have a significant reduction in major myelin protein and gene expression. By immunohistochemistry, the number of total and mature oligodendrocytes was significantly lower in Klotho knock-out mice. Strikingly, at the ultrastructural level, Klotho knock-out mice exhibited significantly impaired myelination of the optic nerve and corpus callosum. These mice also displayed severe abnormalities at the nodes of Ranvier. To decipher the mechanisms by which Klotho affects oligodendrocytes, we used luciferase pathway reporters to identify the transcription factors involved. Together, these studies provide novel evidence for Klotho as a key player in myelin biology, which may thus be a useful therapeutic target in efforts to protect brain myelin against age-dependent changes and promote repair in multiple sclerosis.

Multiple sclerosis is a common demyelinating disease that worsens over the course of disease, a significant problem in clinical management. Disability in MS is significantly promoted by poor repair and remyelination of lesions. Both oligodendrocyte recruitment and maturation defects are seen as major causes of poor remyelination in MS. The mechanisms behind impaired remyelination in animal models include involvement of the Notch1, wnt, and hyaluronan/TLR2 pathways. RXR/PPAR signaling has also more recently been identified as an important regulator of remyelination. The local inflammatory milieu also appears to play critical and conflicting roles in promotion and inhibition of remyelination in MS. Understanding the forces regulating remyelination in MS represents an exciting and important initial step towards developing therapeutics targeting chronic disability in MS., (Copyright © 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

Failure of remyelination is largely responsible for sustained neurologic symptoms in multiple sclerosis (MS). MS lesions contain hyaluronan deposits that inhibit oligodendrocyte precursor cell (OPC) maturation. However, the mechanism behind this inhibition is unclear. We report here that Toll-like receptor 2 (TLR2) is expressed by oligodendrocytes and is up-regulated in MS lesions. Pathogen-derived TLR2 agonists, but not agonists for other TLRs, inhibit OPC maturation in vitro. Hyaluronan-mediated inhibition of OPC maturation requires TLR2 and MyD88, a TLR2 adaptor molecule. Ablated expression of TLR2 also enhances remyelination in a lysolecithin animal model. Hyaluronidases expressed by OPCs degrade hyaluronan to hyaluronan oligomers, a requirement for hyaluronan/TLR2 signaling. MS lesions contain both TLR2(+) oligodendrocytes and low-molecular-weight hyaluronan, consistent with their importance to remyelination in MS. We thus have defined a mechanism controlling remyelination failure in MS where hyaluronan is degraded by hyaluronidases into hyaluronan oligomers that block OPC maturation and remyelination through TLR2-MyD88 signaling.

Neurologic disease promoted by microbial pathogens, sterile injury, or neurodegeneration rapidly induces innate immunity in adjacent healthy tissue, which in turn contributes extensively to neurologic injury. With more recent focus on innate immune processes, it appears that necrotic, but not apoptotic, death mechanisms provoke inflammatory responses likely due to the release or production of endogenous ligands that activate resident immune cells of the central nervous system. These ligands comprise a diverse set of proteins, nucleic acids, and glycosaminoglycans, including heat shock proteins, HMGB1, RNA, DNA, hyaluronan, and heparin sulfate, that stimulate innate immune mechanisms largely through Toll-like receptors (TLRs). The blockade of interactions between endogenous ligands and TLRs may enable neuroprotective therapeutic strategies for a variety of neurologic diseases.

Toll is a cell surface receptor with well described roles in the developmental patterning of invertebrates and innate immunity in adult Drosophila. Mammalian toll-like receptors represent a family of Toll orthologs that function in innate immunity by recognizing molecular motifs unique to pathogens or injured tissue. One member in this family of pattern recognition receptors, toll-like receptor 3 (TLR3), recognizes viral double-stranded RNA and host mRNA. We examined the expression and function of TLRs in the nervous system and found that TLR3 is expressed in the mouse central and peripheral nervous systems and is concentrated in the growth cones of neurons. Activation of TLR3 by the synthetic ligand polyinosine:polycytidylic acid (poly I:C) or by mRNA rapidly causes growth cone collapse and irreversibly inhibits neurite extension independent of nuclear factor kappaB. Mice lacking functional TLR3 were resistant to the neurodegenerative effects of poly I:C. Neonatal mice injected with poly I:C were found to have fewer axons exiting dorsal root ganglia and displayed related sensorimotor deficits. No effect of poly I:C was observed in mice lacking functional TLR3. Together, these findings provide evidence that an innate immune pattern recognition receptor functions autonomously in neurons to regulate axonal growth and advances a novel hypothesis that this class of receptors may contribute to injury and limited CNS regeneration.

A product of myosin Va mutations, Griscelli's syndrome type 1 (GS1) is characterized by several neurologic deficits including quadraparesis, mental retardation, and seizures. Although multiple studies have not clearly established a cause for the neurologic deficits linked with GS1, a few reports suggest that GS1 is associated with abnormal myelination, which could cause the neurologic deficits seen with GS1. In this report, we investigate whether myosin Va is critical to oligodendrocyte morphology and to myelination in vivo. We found that myosin Va-null mice exhibit significantly impaired myelination of the brain, optic nerve, and spinal cord. Oligodendrocytes express myosin Va and loss of myosin Va function resulted in significantly smaller lamellas and decreased process number, length, and branching of oligodendrocytes. Loss of myosin Va function also blocked distal localization of vesicle-associated membrane protein 2 (VAMP2), which is known to associate with myosin Va. When VAMP2 function was disrupted, oligodendrocytes exhibited similar morphologic deficits to what is seen with functional ablation of myosin Va. Our findings establish a role for both myosin Va and VAMP2 in oligodendrocyte function as it relates to myelination.