The measurement and clinical relevance of brain atrophy in multiple sclerosis

Quantifying disease pathology and predicting disease progression in multiple sclerosis with only clinical routine T2-FLAIR MRI

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We explored five brain pathology measures from clinical-quality T2-FLAIR MRI in MS.

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These included LVV, thalamus volume, MOV, SCLV and network efficiency.

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T2-FLAIR measures predicted a majority of the variance in research-quality MRI.

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T2-FLAIR measures correlated with neurologic disability and cognitive function.

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T2-FLAIR measures predicted disability progression over five-years.

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T2-FLAIR measures can be used in legacy clinical datasets.

Background

Although quantitative measures from research-quality MRI provide a means to study multiple sclerosis (MS) pathology in vivo, these metrics are often unavailable in legacy clinical datasets.

Objective

To determine how well an automatically-generated quantitative snapshot of brain pathology, measured only on clinical routine T2-FLAIR MRI, can substitute for more conventional measures on research MRI in terms of capturing multi-factorial disease pathology and providing similar clinical relevance.

Methods

MRI with both research-quality sequences and conventional clinical T2-FLAIR was acquired for 172 MS patients at baseline, and neurologic disability was assessed at baseline and five-years later. Five measures (thalamus volume, lateral ventricle volume, medulla oblongata volume, lesion volume, and network efficiency) for quantifying disparate aspects of neuropathology from low-resolution T2-FLAIR were applied to predict standard research-quality MRI measures. They were compared in regard to association with future neurologic disability and disease progression over five years.

Results

The combination of the five T2-FLAIR measures explained most of the variance in standard research-quality MRI. T2-FLAIR measures were associated with neurologic disability and cognitive function five-years later (R² = 0.279, p < 0.001; R² = 0.382, p < 0.001), similar to standard research-quality MRI (R² = 0.279, p < 0.001; R² = 0.366, p < 0.001). They also similarly predicted disability progression over five years (%-correctly-classified = 69.8, p = 0.034), compared to standard research-quality MRI (%-correctly-classified = 72.4%, p = 0.022) in relapsing-remitting MS.

Conclusion

A set of five T2-FLAIR-only measures can substitute for standard research-quality MRI, especially in relapsing-remitting MS. When only clinical T2-FLAIR is available, it can be used to obtain substantially more quantitative information about brain pathology and disability than is currently standard practice.

Retinal layer thinning predicts treatment failure in relapsing multiple sclerosis

Background and purpose

Peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell plus inner plexiform layer (GCIPL) thinning are markers of neuroaxonal degeneration in multiple sclerosis (MS), which is reduced by disease‐modifying treatment (DMT). We aimed to investigate the potential of pRNFL and GCIPL thinning for prediction of DMT failure in relapsing MS (RMS).

Methods

In this 4‐year prospective observational study on 113 RMS patients, pRNFL and GCIPL were measured at DMT initiation and after 12 months (M12) and 24 months (M24). Treatment failure was defined as 6‐month confirmed Expanded Disability Status Scale (EDSS) progression and/or Symbol Digit Modalities Test (SDMT) worsening. Optimal cutoff values for predicting treatment failure were determined by receiver operating characteristic analyses and hazard ratios (HRs) by multivariable Cox regression adjusting for age, sex, disease duration, EDSS/SDMT, and DMT class.

Results

Thinning of GCIPL >0.5 μm/year at M24 showed superior value for treatment failure prediction (HR: 4.5, 95% confidence interval [CI]: 1.8–7.6, p < 0.001; specificity 91%, sensitivity 81%), followed by GCIPL >0.5 μm at M12 (odds ratio [OR]: 3.9, 95% CI: 1.4–6.9, p < 0.001; specificity 85%, sensitivity 78%), and pRNFL ≥2 μm/year at M24 (OR: 3.7, 95% CI: 1.1–6.5, p = 0.023; specificity 84%, sensitivity 69%), whereas pRNFL at M12 was not predictive.

Conclusions

GCIPL, and to a lesser degree pRNFL, thinning predicts disability progression after DMT initiation and may be a useful and accessible biomarker of treatment failure in RMS.

Evaluation of Retinal Layer Thickness Parameters as Biomarkers in a Real-World Multiple Sclerosis Cohort

Purpose

Retinal layer thickness parameters measured by optical coherence tomography (OCT) are emerging biomarkers of neuroaxonal degeneration and inflammation in multiple sclerosis (MS). We aimed to evaluate the value of retinal layer thickness for prediction of disability worsening and relapse in a real-world MS cohort.

Patients and Methods

For this longitudinal observational study, we included MS patients with spectral-domain OCT scans available and ≥1 year of clinical follow-up. The value of peripapillary retinal nerve fiber layer (pRNFL), macular ganglion-cell-and-inner-plexiform-layer (GCIPL) and inner nuclear layer (INL) thickness for prediction of disability worsening and relapse during the observation period was tested by multivariate models.

Results

We analyzed 60 MS patients during a mean observation period of 2.9 years (SD 1.8). Lower baseline thickness of GCIPL (cut-off <77µm; HR 4.1, p=0.001) and pRNFL (cut-off ≤88µm; HR 3.1, p=0.019) were associated with an increased risk of disability worsening. Longitudinally, mean thinning rates were −0.8µm/year (SD 1.6) for GCIPL, −0.6µm/year (SD 3.5) for pRNFL. GCIPL thinning ≥1.0µm/year and pRNFL >1.5µm/year is associated with higher likelihood of disability worsening (HR 5.7, p=0.009 and HR 6.8, p=0.003, respectively). INL thickened in patients with relapse by a mean 0.9µm while thinning by 0.3µm in patients without relapse (p=0.04). In multivariate analyses, INL thickening was associated with an increased probability of relapse (OR 17.8, p=0.023).

Conclusion

Cross-sectional and longitudinal measurement of GCIPL and pRNFL thinning is reliable as a biomarker of disability worsening in a real-world setting. Change of INL thickness is a promising marker of relapse, i.e. inflammatory activity.

Brain TSPO-PET predicts later disease progression independent of relapses in multiple sclerosis

Overactivation of microglia is associated with most neurodegenerative diseases. In this study we examined whether PET-measurable innate immune cell activation predicts multiple sclerosis disease progression. Activation of microglia/macrophages was measured using the 18-kDa translocator protein (TSPO)-binding radioligand ¹¹C-PK11195 and PET imaging in 69 patients with multiple sclerosis and 18 age- and sex-matched healthy controls. Radioligand binding was evaluated as the distribution volume ratio from dynamic PET images. Conventional MRI and disability measurements using the Expanded Disability Status Scale were performed for patients at baseline and 4.1 ± 1.9 (mean ± standard deviation) years later. Fifty-one (74%) of the patients were free of relapses during the follow-up period. Patients had increased activation of innate immune cells in the normal-appearing white matter and in the thalamus compared to the healthy control group (P = 0.033 and P = 0.003, respectively, Wilcoxon). Forward-type stepwise logistic regression was used to assess the best variables predicting disease progression. Baseline innate immune cell activation in the normal-appearing white matter was a significant predictor of later progression when the entire multiple sclerosis cohort was assessed [odds ratio (OR) = 4.26; P = 0.048]. In the patient subgroup free of relapses there was an association between macrophage/microglia activation in the perilesional normal-appearing white matter and disease progression (OR = 4.57; P = 0.013). None of the conventional MRI parameters measured at baseline associated with later progression. Our results strongly suggest that innate immune cell activation contributes to the diffuse neural damage leading to multiple sclerosis disease progression independent of relapses.

Gray Matter Atrophy in the Cortico-Striatal-Thalamic Network and Sensorimotor Network in Relapsing-Remitting and Primary Progressive Multiple Sclerosis

Gray matter atrophy in multiple sclerosis (MS) is thought to be associated with disability and cognitive impairment, but previous studies have sometimes had discordant results, and the atrophy patterns of relapsing-remitting multiple sclerosis (RRMS) and primary progressive multiple sclerosis (PPMS) remain to be clarified. We conducted a meta-analysis using anisotropic effect-size-based algorithms (AES-SDM) to identify consistent findings from whole-brain voxel-based morphometry (VBM) studies of gray matter volume (GMV) in 924 RRMS patients and 204 PPMS patients. This study is registered with PROSPERO (number CRD42019121319). Compared with healthy controls, RRMS and PPMS patients showed gray matter atrophy in the cortico-striatal-thalamic network, sensorimotor network, and bilateral insula. RRMS patients had a larger GMV in the left insula, cerebellum, right precentral gyrus, and bilateral putamen as well as a smaller GMV in the bilateral cingulate, caudate nucleus, right thalamus, superior temporal gyrus and left postcentral gyrus than PPMS patients. The disease duration, Expanded Disability Status Scale score, Paced Auditory Serial Addition Test z-score, and T2-weighted lesion load were associated with specific gray matter regions in RRMS or PPMS. Alterations in the cortico-striatal-thalamic networks, sensorimotor network, and insula may be involved in the common pathogenesis of RRMS and PPMS. The deficits in the cingulate gyrus and caudate nucleus are more apparent in RRMS than in PPMS. The more severe cerebellum atrophy in PPMS may be a brain feature associated with its neurological manifestations. These imaging biomarkers provide morphological evidence for the pathophysiology of MS and should be verified in future research.

Imaging Mechanisms of Disease Progression in Multiple Sclerosis: Beyond Brain Atrophy

Clinicians involved with different aspects of the care of persons with multiple sclerosis (MS) and scientists with expertise on clinical and imaging techniques convened in Dallas, TX, USA on February 27, 2019 at a North American Imaging in Multiple Sclerosis Cooperative workshop meeting. The aim of the workshop was to discuss cardinal pathobiological mechanisms implicated in the progression of MS and novel imaging techniques, beyond brain atrophy, to unravel these pathologies. Indeed, although brain volume assessment demonstrates changes linked to disease progression, identifying the biological mechanisms leading up to that volume loss are key for understanding disease mechanisms. To this end, the workshop focused on the application of advanced magnetic resonance imaging (MRI) and positron emission tomography (PET) imaging techniques to assess and measure disease progression in both the brain and the spinal cord. Clinical translation of quantitative MRI was recognized as of vital importance, although the need to maintain a relatively short acquisition time mandated by most radiology departments remains the major obstacle toward this effort. Regarding PET, the panel agreed upon its utility to identify ongoing pathological processes. However, due to costs, required expertise, and the use of ionizing radiation, PET was not considered to be a viable option for ongoing care of persons with MS. Collaborative efforts fostering robust study designs and imaging technique standardization across scanners and centers are needed to unravel disease mechanisms leading to progression and discovering medications halting neurodegeneration and/or promoting repair.

Should We Use Clinical Tools to Identify Disease Progression?

The presence of disability progression in multiple sclerosis (MS) is an important hallmark for MS patients in the course of their disease. The transition from relapsing remitting (RRMS) to secondary progressive forms of the disease (SPMS) represents a significant change in their quality of life and perception of the disease. It could also be a therapeutic key for opportunities, where approaches different from those in the initial phases of the disease can be adopted. The characterization of structural biomarkers (e.g., magnetic resonance imaging or neurofilament light chain) has been proposed to differentiate between both phenotypes. However, there is no definite threshold between them. Whether the risk of clinical progression can be predicted by structural markers at early disease phases is still a focus of clinical research. However, several theories and pathological evidence suggest that both disease phenotypes are part of a continuum with common pathophysiological mechanisms. In this case, the clinical evaluation of the patients would play a preponderant role above destruction biomarkers for the early identification of disability progression and SPMS. For this purpose, the use of clinical tools beyond the Expanded Disability Status Scale (EDSS) should be considered. Besides established functional tests such as the Multiple Sclerosis Functional Composite (MSFC), patient's neurological history or digital resources may help neurologists in the decision-taking. In this article, we discuss arguments for the use of clinical markers in the detection of secondary progressive MS and the characterization of progressive disease activity.

Perilesional neurodegenerative injury in multiple sclerosis: Relation to focal lesions and impact on disability

BACKGROUND

Axonal injury is the primary source of irreversible neurological decline in persons with multiple sclerosis (pwMS). Identifying and quantifying myelin and axonal loss in lesional and perilesional tissue in vivo is fundamental for a better understanding of multiple sclerosis (MS) outcomes and patient impairment. Using advanced magnetic resonance imaging (MRI) methods, consisting of selective inversion recovery quantitative magnetization transfer imaging (SIR-qMT) and multi-compartment diffusion MRI with the spherical mean technique (SMT), we conducted a cross-sectional pilot study to assess myelin and axonal damage in the normal appearing white matter (NAWM) surrounding chronic black holes (cBHs) and how this pathology correlates with disability in vivo. We hypothesized that lesional axonal transection propagates tissue injury in the surrounding NAWM and that the degree of this injury is related to patient disability.

METHODS

Eighteen pwMS underwent a 3.0 Tesla conventional clinical MRI, inclusive of T1 and T2 weighted protocols, as well as SIR-qMT and SMT. Regions of interests (ROIs) were manually delineated in cBHs, NAWM neighboring cBHs (perilesional NAWM), distant ipsilateral NAWM and contra-lateral distant NAWM. SIR-qMT-derived macromolecular-to-free pool size ratio (PSR) and SMT-derived apparent axonal volume fraction (V_ax) were extracted to infer on myelin and axonal content, respectively. Group differences were assessed using mixed-effects regression models and correlation analyses were obtained by bootstrapping 95% confidence interval.

RESULTS

In comparison to perilesional NAWM, both PSR and V_ax values were reduced in cBHs (p < 0.0001) and increased in distant contra-lateral NAWM ROIs (p < 0.001 for PSR and p < 0.0001 for V_ax) but not ipsilateral NAWM (p = 0.176 for PSR and p = 0.549 for V_ax). V_ax values measured in cBHs correlated with those in perilesional NAWM (Pearson rho = 0.63, p < 0.001). No statistically relevant associations were seen between PSR/V_ax values and clinical and/or MRI metrics of the disease with the exception of cBH PSR values, which correlated with the Expanded Disability Status Scale (Pearson rho = -0.63, p = 0.03).

CONCLUSIONS

Our results show that myelin and axonal content, detected by PSR and V_ax, are reduced in perilesional NAWM, as a function of the degree of focal cBH axonal injury. This finding is indicative of an ongoing anterograde/retrograde degeneration and suggests that treatment prevention of cBH development is a key factor for preserving NAWM integrity in surrounding tissue. It also suggests that measuring changes in perilesional areas over time may be a useful measure of outcome for proof-of-concept clinical trials on neuroprotection and repair. PSR and V_ax largely failed to capture associations with clinical and MRI characteristics, likely as a result of the small sample size and cross-sectional design, however, longitudinal assessment of a larger cohort may unravel the impact of this pathology on disease progression.

Learning joint segmentation of tissues and brain lesions from task-specific hetero-modal domain-shifted datasets

Brain tissue segmentation from multimodal MRI is a key building block of many neuroimaging analysis pipelines. Established tissue segmentation approaches have, however, not been developed to cope with large anatomical changes resulting from pathology, such as white matter lesions or tumours, and often fail in these cases. In the meantime, with the advent of deep neural networks (DNNs), segmentation of brain lesions has matured significantly. However, few existing approaches allow for the joint segmentation of normal tissue and brain lesions. Developing a DNN for such a joint task is currently hampered by the fact that annotated datasets typically address only one specific task and rely on task-specific imaging protocols including a task-specific set of imaging modalities. In this work, we propose a novel approach to build a joint tissue and lesion segmentation model from aggregated task-specific hetero-modal domain-shifted and partially-annotated datasets. Starting from a variational formulation of the joint problem, we show how the expected risk can be decomposed and optimised empirically. We exploit an upper bound of the risk to deal with heterogeneous imaging modalities across datasets. To deal with potential domain shift, we integrated and tested three conventional techniques based on data augmentation, adversarial learning and pseudo-healthy generation. For each individual task, our joint approach reaches comparable performance to task-specific and fully-supervised models. The proposed framework is assessed on two different types of brain lesions: White matter lesions and gliomas. In the latter case, lacking a joint ground-truth for quantitative assessment purposes, we propose and use a novel clinically-relevant qualitative assessment methodology.

Patient and Neurologist Preferences in the United States for Relapsing-Remitting Multiple Sclerosis Treatments: Findings from a Discrete Choice Experiment

BACKGROUND AND OBJECTIVE

Relapsing-remitting multiple sclerosis (RRMS) is a chronic inflammatory disease associated with central nervous system dysfunction and accelerated brain volume loss (BVL). There exists a paucity of research examining the importance of BVL to patients and neurologists and exploring whether such preferences may differ between these two groups. This study sought to evaluate the preferences of patients and neurologists for RRMS treatments by considering benefits and risks associated with novel and common disease-modifying therapies (DMTs).

PATIENTS AND METHODS

US patients diagnosed with non-highly active RRMS and US-based neurologists completed an online cross-sectional survey. A discrete choice experiment was used to assess patient and neurologist treatment preferences, with neurologists considering preferences for patients with non-highly active RRMS. Respondents chose between two treatment profiles with seven attributes identified in qualitative research: 2-year disability progression; 1-year relapse rate; rate of BVL; and risks of gastrointestinal symptoms, flu-like symptoms, infection, and life-threatening events. Attribute-level weighted preferences were estimated using a hierarchical Bayesian model.

RESULTS

Analyses included 150 patients with non-highly active RRMS (mean age: 54 years) and 150 neurologists (65% in private practice). Among patients, the most important treatment attribute was reducing the rate of BVL, followed by reducing the risk of infection and risk of flu-like symptoms. In contrast, the most important treatment attribute among neurologists was reducing the risk of a life-threatening event, followed by slowing the rate of 2-year disability progression and risk of infection.

CONCLUSION

The findings highlight differences in treatment preferences between US patients and neurologists for non-highly active RRMS. The importance placed by patients on slowing the rate of BVL makes this a key topic that should be covered in the shared decision-making process.

Physical activity monitoring to assess disability progression in multiple sclerosis

Background

Clinical outcome measurement in multiple sclerosis (MS) usually requires a physical visit. Remote activity monitoring (RAM) using wearable technology provides a rational alternative, especially desirable when distance is involved or in a pandemic setting.

Objective

To validate RAM in progressive MS using (1) traditional psychometric methods (2) brain atrophy.

Methods

56 people with progressive MS participated in a longitudinal study over 2.5 years. An arm-worn RAM device measured activity over six days, every six months, and incorporated triaxial accelerometry and transcutaneous physiological variable measurement. Five RAM variables were assessed: physical activity duration, step count, active energy expenditure, metabolic equivalents and a composite RAM score incorporating all four variables. Other assessments every six months included EDSS, MSFC, MSIS-29, Chalder Fatigue Scale and Beck’s Depression Inventory. Annualized brain atrophy was measured using SIENA.

Results

RAM was tolerated well by people with MS; the device was worn 99.4% of the time. RAM had good convergent and divergent validity and was responsive, especially with respect to step count. Measurement of physical activity over one day was as responsive as six days. The composite RAM score positively correlated with brain volume loss.

Conclusion

Remote activity monitoring is a valid and acceptable outcome measure in MS.

Temporal profile of serum neurofilament light in multiple sclerosis: Implications for patient monitoring

Objective:

To understand how longitudinal serum neurofilament light chain (sNfL) patterns can inform its use as a prognostic biomarker in multiple sclerosis (MS) and evaluate whether sNfL reflects MS disease activity and disease-modifying therapy usage.

Methods:

This was a post hoc analysis of longitudinal data and samples from the ADVANCE trial (NCT00906399) of patients with relapsing–remitting MS (RRMS). sNfL was measured every 3 months for 2 years, then every 6 months for 4 years. Regression models explored how sNfL data predicted 4-year values of brain volume, expanded disability status scale score, and T2 lesions. sNfL levels were assessed in those receiving placebo, peginterferon beta-1a, and those with disease activity.

Results:

Baseline sNfL was a predictor of 4-year brain atrophy and development of new T2 lesions. Clinical (p = 0.02) and magnetic resonance imaging (MRI) (p < 0.01) outcomes improved in those receiving peginterferon beta-1a whose sNfL decreased to <16 pg/mL after 12 months versus those whose sNfL remained ⩾16 pg/mL. Mean sNfL levels decreased in peginterferon beta-1a-treated patients and increased in placebo-treated patients (–9.5% vs. 6.8%; p < 0.01). sNfL was higher and more variable in patients with evidence of active MS.

Conclusion:

These data support sNfL as a prognostic and disease-monitoring biomarker for RRMS.

Cortical Thinning and Ventricle Enlargement in Neuromyelitis Optica Spectrum Disorders

Background: In neuromyelitis optica spectrum disorders (NMOSDs), inflammation is not the sole driver of accumulation of disability; neurodegeneration is another important pathological process. We aim to explore different patterns of cortical atrophy and ventricular enlargement in NMOSD.

Methods: We retrospectively analyzed a cohort of 230 subjects, comprising 55 healthy controls (HCs), 85 multiple sclerosis (MS), and 90 NMOSD patients from Tianjin Medical University General Hospital and Beijing Tiantan Hospital. Different compartments of the brain (total gray, cortex, subcortex gray, and ventricle volume) were evaluated with the FreeSurfer. Multiple linear regressions were adopted to explore associations between cortex volume and predict factors.

Results: Compared with HCs, NMOSD, and MS displayed an enlarged lateral and third ventricle (p < 0.001), whereas expansion of the fourth ventricle was observed in MS rather than NMOSD (p = 0.321). MS and NMOSD patients exhibited cortical thinning in comparison with HCs. However, pronounced cortical atrophy were only significant in pre-cuneus, parahippocampal, and lateral occipital lobe between MS and NMOSD. Patients with NMOSD had decreased local gyrification index in orbitofrontal and pre-cuneus lobe, and reduced pial surface area. Linear regression analysis revealed cortex volume were predicated by advanced age (standardized β = −0.404, p = 0.001) as well as prolonged disease history (standardized β = −0.311, p = 0.006).

Conclusion: NMOSD exhibited global cortex atrophy with enlarged lateral and third ventricles. Moreover, cortex volume is associated with age and disease duration.

Motor fatigue is associated with asymmetric connectivity properties of the corticospinal tract in multiple sclerosis

Multiple Sclerosis (MS) is characterized by demyelination and neurodegeneration of the central nervous system and causes excessive fatigue in more than 80% of the patients. The pathophysiologic mechanisms causing fatigue are still largely unknown. In 46 right-handed patients with relapsing-remitting MS and 25 right-handed controls, we performed diffusion MRI and applied streamline based probabilistic tractography to derive unilateral anatomical connectivity maps for the white matter of the right and left hemispheres. The maps provide an indication how often a streamline has passed through a given voxel. Since tractography based anatomical connectivity mapping (ACM) is sensitive to disease-induced changes in anatomical connectivity, we used ACM to test whether motor fatigue is associated with altered ipsi-hemispherical anatomical connectivity in the major motor output pathway, the corticospinal tract (CST). Patients had higher mean ACM values in the CST than healthy controls. This indicated that a higher number of streamlines, starting from voxels in the same hemisphere, travelled through the CST and may reflect an accumulated disease-induced disintegration of CST. The motor subscale of the Fatigue Scale for Motor and Cognitive functions (FSMCMOTOR) was used to define sub-groups with (n = 29, FSMCMOTOR score ≥ 27) and without motor fatigue (n = 17, FSMSMOTOR score ≤ 26). Patients without fatigue only showed higher ACM values in right CST, while mean ACM values were unaltered in left CST. The higher the mean ACM values in the left relative to the right CST, the more patients reported motor fatigue. Left-right asymmetry in anatomical connectivity outside the CST did not scale with individual motor fatigue. Our results link lateralized changes of tractography-based microstructural properties in the CST with motor fatigue in relapsing-remitting MS.

Alexithymia in multiple sclerosis: Clinical and radiological correlations

BACKGROUND

Alexithymia, meaning no words for emotions is a common problem that could affect up to 53% of patients in multiple sclerosis (MS).

OBJECTIVES

To determine the frequency of alexithymia in MS and investigate MS-related abnormalities in structural magnetic resonance imaging (MRI) and their associations with fatigue and cognitive functions.

METHODS

Ninety-five patients at all stages of the disease were examined: 21 with clinically isolated syndromes (CIS), 30 with relapsing-remitting MS (RRMS), 21 with primary (PP) and 23 with secondary progressive MS (SPMS). Alexithymia was measured with the Toronto alexithymia scale (TAS-20) and correlated to cognitive functions, depression, and fatigue. Voxel-based morphometry MRI was analyzed to determine lesion load, cerebral and regional atrophy.

RESULTS

Fifty-seven of patients had alexithymia with no significant difference between the clinical phenotypes. Alexithymic patients differed from non-alexithymic patients on fatigue, depression and information processing speed. Compared to non-alexithymic patients, alexithymic patients had decreased volumes of cerebral and cerebellar white matter and there was a significant relationship between alexithymia and decreased brainstem, thalamic and corpus callosum volume.

CONCLUSION

Regardless of the phenotype of MS, alexithymia is associated with atrophy of cerebral and cerebellar white matter, brainstem, corpus callosum, and thalami.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

The TOTEM RRMS (Testosterone Treatment on neuroprotection and Myelin Repair in Relapsing Remitting Multiple Sclerosis) trial: study protocol for a randomized, double-blind, placebo-controlled trial

BACKGROUND

Central nervous system damage in multiple sclerosis (MS) is responsible for serious deficiencies. Current therapies are focused on the treatment of inflammation; however, there is an urgent need for innovative therapies promoting neuroregeneration, particularly myelin repair. It is demonstrated that testosterone can act through neural androgen receptors and several clinical observations stimulated an interest in the potential protective effects of testosterone treatment for MS. Here, we sought to demonstrate the effects of a testosterone supplementation in testosterone-deficient men with relapsing-remitting MS.

METHODS/DESIGN

This report presents the rationale and methodology of TOTEM RRMS, a French, phase 2, multicenter, randomized, placebo-controlled, and double-blind trial, which aims to prevent the progression of MS in men with low testosterone levels by administration of testosterone undecanoate, who were kept under natalizumab (Tysabri®) to overcome the anti-inflammatory effect of testosterone. Forty patients will be randomized into two groups receiving either a testosterone treatment (Nebido®) or a matching placebo. The intervention period for each group will last 66 weeks (treatment will be injected at baseline, week 6, and then every 12 weeks). The main objective is to determine the neuroprotective and remyelinating effects of testosterone using tensor diffusion imaging techniques and thalamic atrophy analyses. As secondary objectives, impacts of the testosterone supplementation will be studied using other conventional and unconventional MRI parameters and with clinical outcomes.

DISCUSSION

The action of testosterone is observed in different experimental autoimmune encephalomyelitis models and epidemiological studies in humans. However, despite several preclinical data and some small clinical trials in MS, clear evidence for a therapeutic effect of hormone therapy is still missing. Therefore, our goal is to demonstrate the effects of testosterone therapies in MS. As there is no effective treatment currently available on fatigue in MS, careful attention should also be paid to secondary endpoints: fatigue, cognitive functions, and other symptoms that may improve life quality. Assuming a positive outcome of the trial, this treatment could be considered as a new neuroprotective and remyelinating therapy in relapsing-remitting MS and could be applicable to other demyelinating diseases.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03910738. Registered on 10 April 2019.

Visualizing the Central Nervous System: Imaging Tools for Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders

Multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) are autoimmune central nervous system conditions with increasing incidence and prevalence. While MS is the most frequent inflammatory CNS disorder in young adults, NMOSD is a rare disease, that is pathogenetically distinct from MS, and accounts for approximately 1% of demyelinating disorders, with the relative proportion within the demyelinating CNS diseases varying widely among different races and regions. Most immunomodulatory drugs used in MS are inefficacious or even harmful in NMOSD, emphasizing the need for a timely and accurate diagnosis and distinction from MS. Despite distinct immunopathology and differences in disease course and severity there might be considerable overlap in clinical and imaging findings, posing a diagnostic challenge for managing neurologists. Differential diagnosis is facilitated by positive serology for AQP4-antibodies (AQP4-ab) in NMOSD, but might be difficult in seronegative cases. Imaging of the brain, optic nerve, retina and spinal cord is of paramount importance when managing patients with autoimmune CNS conditions. Once a diagnosis has been established, imaging techniques are often deployed at regular intervals over the disease course as surrogate measures for disease activity and progression and to surveil treatment effects. While the application of some imaging modalities for monitoring of disease course was established decades ago in MS, the situation is unclear in NMOSD where work on longitudinal imaging findings and their association with clinical disability is scant. Moreover, as long-term disability is mostly attack-related in NMOSD and does not stem from insidious progression as in MS, regular follow-up imaging might not be useful in the absence of clinical events. However, with accumulating evidence for covert tissue alteration in NMOSD and with the advent of approved immunotherapies the role of imaging in the management of NMOSD may be reconsidered. By contrast, MS management still faces the challenge of implementing imaging techniques that are capable of monitoring progressive tissue loss in clinical trials and cohort studies into treatment algorithms for individual patients. This article reviews the current status of imaging research in MS and NMOSD with an emphasis on emerging modalities that have the potential to be implemented in clinical practice.

The impact of multiple sclerosis relapses on worsening over the long term; insights in the treatment era

Relapses of multiple sclerosis (MS) are the clinical manifestations of inflammatory events involving eloquent anatomical structures within the central nervous system. Relapses are associated with worsening disability of MS patients in both early and later disease, even after progressive features are seen. The impact of relapses on the long-term course of the disease is now being realized as a generation of treated patients is now elderly. New MRI brain lesions can be viewed as a radiologic manifestation of acute inflammation and are associated with similar prognostic value. The complex relationship between clinical relapse activity and later slow progressive worsening remains incompletely understood, however, there is increasing biological plausibility for a causative association between relapse activity and lifelong disability.

Impact of autologous haematopoietic stem cell transplantation on disability and brain atrophy in secondary progressive multiple sclerosis

Background:

Autologous haematopoietic stem cell transplantation (aHSCT) is a valuable option in aggressive relapsing–remitting multiple sclerosis (MS), but its efficacy in secondary progressive (SP)-MS is still controversial.

Objective:

Assessing efficacy of aHSCT in SP-MS by clinical-radiological outcomes.

Methods:

Open-label monocentric retrospective study enrolling consecutive SP-MS patients treated with BEAM-aHSCT in the period 1999–2016.

Results:

In total, 26 SP-MS patients with moderate–severe disability were included. Progression-free survival (PFS) at years 5 and 10 after aHSCT were, respectively, 42% and 30%. Out of 16 patients who worsened, only 6 patients (23% overall) maintained continuous disability accrual (CDA), whereas 10 patients stabilized following one single-step Expanded Disability Status Scale (EDSS) worsening. CDA-free survival was 74% at 5–10 years. No relapses or magnetic resonance imaging (MRI) activity were reported, thus no evidence of disease activity (NEDA)-3 corresponded to PFS. Annualized rate of brain atrophy (AR-BVL) normalized after 1 year in 55% of the cases analysed (12/22).

Conclusion:

BEAM-aHSCT halted CDA and normalized AR-BVL in most of the treated patients, inducing long-term remission of inflammatory activity at a median follow-up of 99 months (range 27–222). These data suggest that CDA might still be mainly driven by inflammation in a subgroup of SP-MS and could therefore be reversed by treatments. CDA should be analysed independently from any isolated disability worsening.

Is It Possible to Conduct a Multi-Arm Multi-Stage Platform Trial in Parkinson's Disease: Lessons Learned from Other Neurodegenerative Disorders and Cancer

Many potential disease modifying therapies have been identified as suitable for clinical evaluation in Parkinson's disease (PD). Currently, the evaluation of compounds in phase II and phase III clinical trials in PD are set up in isolation, a process that is lengthy, costly and lacks efficiency. This review will introduce the concept of a multi-arm, multi-stage (MAMS) trial platform which allows for the assessment of several potential therapies at once, transitioning seamlessly from a phase II safety and efficacy study to a phase III trial by means of an interim analysis. At the interim checkpoint, ineffective arms are dropped and replaced by new treatment arms, thereby allowing for the continuous evaluation of interventions. MAMS trial platforms already exist for prostate, renal and oropharyngeal cancer and are currently being developed for progressive multiple sclerosis (PMS) and motor neuron disease (MND) within the UK. As a MAMS trial will evaluate many potential treatments it is of critical importance that a widely endorsed core protocol is developed which will investigate outcomes and objectives meaningful to patients. This review will discuss the challenges of drug selection, trial design, stratification and outcome measures and will share strategies implemented in the planned MAMS trials for MND and PMS that may be of interest to the PD field.

Brain atrophy in multiple sclerosis: mechanisms, clinical relevance and treatment options

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system characterized by focal or diffuse inflammation, demyelination, axonal loss and neurodegeneration. Brain atrophy can be seen in the earliest stages of MS, progresses faster compared to healthy adults, and is a reliable predictor of future physical and cognitive disability. In addition, it is widely accepted to be a valid, sensitive and reproducible measure of neurodegeneration in MS. Reducing the rate of brain atrophy has only recently been incorporated as a critical endpoint into the clinical trials of new or emerging disease modifying drugs (DMDs) in MS. With the advent of easily accessible neuroimaging softwares along with the accumulating evidence, clinicians may be able to use brain atrophy measures in their everyday clinical practice to monitor disease course and response to DMDs. In this review, we will describe the different mechanisms contributing to brain atrophy, their clinical relevance on disease presentation and course and the effect of current or emergent DMDs on brain atrophy and neuroprotection.

An argument for broad use of high efficacy treatments in early multiple sclerosis

Two different treatment paradigms are most often used in multiple sclerosis (MS). An escalation or induction approach is considered when treating a patient early in the disease course. An escalator prioritizes safety, whereas an inducer would favor efficacy. Our understanding of MS pathophysiology has evolved with novel in vivo and in vitro observations. The treatment landscape has also shifted significantly with the approval of over 10 new medications over the past decade alone. Here, we re-examine the treatment approach in light of these recent developments. We believe that recent work suggests that early prediction of the disease course is fraught, the amount of damage to the brain that MS causes is underappreciated, and its impact on patient function oftentimes is underestimated. These concerns, coupled with the recent availability of agents that allow a better therapeutic effect without compromising safety, lead us to believe that initiating higher efficacy treatments early is the best way to achieve the best possible long-term outcomes for people with MS.

The temporal and causal relationship between inflammation and neurodegeneration in multiple sclerosis

It is currently incompletely understood whether inflammation and neurodegeneration are causally related in multiple sclerosis (MS). The sequence of a potential causal relationship is also unknown. Inflammation is present in rather all clinical stages of MS. Its role in the pathogenesis of MS is supported by histopathological analyses, genetic data, and numerous animal models of MS. All approved disease-modifying therapies that reduce clinical relapses and diminish the accumulation of lesions on neuroimaging are anti-inflammatory. Axonal loss and accelerated brain volume loss can also be detected from clinical disease onset throughout all stages. The expression of neurofilament light chain in cerebrospinal fluid and serum, a scaffolding protein in axons and dendrites, is a biomarker of neuronal injury associated with clinical relapses and reflects neuronal loss during episodes of acute inflammation. The recent association of human endogenous retrovirus (HERV) and its envelope proteins with MS illustrates a pathogenic pathway that causally links central nervous system (CNS)-intrinsic proinflammatory effects and inhibition of myelin repair and neuroregeneration. A review of current data on the causal relationship between inflammation and neurodegeneration in MS identified numerous plausible pathomechanisms that link the two events. Observations from most experimental models appear to favor a pathogenesis in which inflammation precedes neurodegeneration.

Atrophied Brain T2 Lesion Volume at MRI Is Associated with Disability Progression and Conversion to Secondary Progressive Multiple Sclerosis

Background Atrophied T2 lesion volume at MRI is an imaging measure that reflects the replacement of T2 lesions by cerebrospinal fluid spaces in patients with multiple sclerosis (MS). Purpose To investigate the association of atrophied T2 lesion volume and development of disability progression (DP) and conversion to secondary progressive MS (SPMS). Materials and Methods This retrospective study included 1612 participants recruited from 2006 to 2016 and followed up for 5 years with clinical and MRI examinations. Accumulation of T2 lesion volume, atrophied T2 lesion volume, percentage brain volume change (PBVC), and percentage ventricular volume change (PVVC) were measured. Disability progression and secondary progressive conversion were defined by using standardized guidelines. Analysis of covariance (ANCOVA) adjusted for age and Cox regression adjusted for age and sex were used to compare study groups and explore associations between MRI and clinical outcomes. Results A total of 1314 patients with MS (1006 women; mean age, 46 years ± 11 [standard deviation]) and 124 patients with clinically isolated syndrome (100 women; mean age, 39 years ± 11) along with 147 healthy control subjects (97 women; mean age, 42 years ± 13) were evaluated. A total of 336 of 1314 (23%) patients developed DP, and in 67 of 1213 (5.5%) the disease converted from clinically isolated syndrome (CIS) or relapsing-remitting MS (RRMS) to SPMS. Patients with conversion to DP had higher atrophied T2 lesion volume (+34.4 mm3; 95% confidence interval [CI]: 17.2 mm3, 51.5 mm3; d = 0.27; P < .001) and PBVC (-0.21%; 95% CI: -0.36%, -0.05%; d = 0.19; P = .042) but not PVVC (0.36%; 95% CI: -0.93%, 1.65%; d = 0.04; P = .89) or T2 lesion volume change (-64.5 mm3; 95% CI: -315.2 mm3, 186.3 mm3; d = 0.03; P = .67) when compared with DP nonconverters. ANCOVA showed that atrophied T2 lesion volume was associated with conversion from CIS or RRMS to SPMS (+26.4 mm3; 95% CI: 4.2 mm3, 56.9 mm3; d = 0.23; P = .002) but not PBVC (-0.14%; 95% CI: -0.46%, 0.18%; d = 0.11; P = .66), PVVC (+0.18%; 95% CI: -2.49%, 2.72%; d = 0.01; P = .75), or T2 lesion volume change (-46.4 mm3; 95% CI: -460.8 mm3, 367.9 mm3; d = 0.03; P = .93). At Cox regression analysis, only atrophied T2 lesion volume was associated with the DP (hazard ratio, 1.23; P < .001) and conversion to SPMS (hazard ratio, 1.16; P = .008). Conclusion Atrophied brain T2 lesion volume is a robust MRI marker of MS disability progression and conversion into a secondary progressive disease course. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Chiang in this issue.

2D in-vivo L-COSY spectroscopy identifies neurometabolite alterations in treated multiple sclerosis

Background

We have applied in vivo two-dimensional (2D) localized correlation spectroscopy (2D L-COSY), in treated relapsing relapsing-remitting multiple sclerosis (RRMS) to identify novel biomarkers in normal-appearing brain parenchyma.

Methods

2D L-COSY magnetic resonance spectroscopy (MRS) spectra were prospectively acquired from the posterior cingulate cortex (PCC) in 45 stable RRMS patients undergoing treatment with Fingolimod, and 40 age and sex-matched healthy control (HC) participants. Average metabolite ratios and clinical symptoms including, disability, cognition, fatigue, and mental health parameters were measured, and compared using parametric and nonparametric tests. Whole brain volume and MRS voxel morphometry were evaluated using SIENAX and the SPM LST toolbox.

Results

Despite the mean whole brain lesion volume being low in this RRMS group (6.8 ml) a significant reduction in PCC metabolite to tCr ratios were identified for multiple N-acetylaspartate (NAA) signatures, gamma-aminobutyric acid (GABA), glutamine and glutamate (Glx), threonine, and isoleucine/lipid. Of the clinical symptoms measured, visuospatial function, attention, and memory were correlated with NAA signatures, Glx, and isoleucine/lipid in the brain.

Conclusions

2D L-COSY has the potential to detect metabolic alterations in the normal-appearing MS brain. Despite examining only a localised region, we could detect metabolic variability associated with symptoms.

Correlation between EDSS scores and cervical spinal cord atrophy at 3T MRI in multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

Cervical spinal cord atrophy (CSCA), which partly reflects the axonal loss in the spinal cord, is increasingly recognized as a valuable predictor of disease outcome. However, inconsistent results have been reported regarding the correlation of CSCA and clinical disability in multiple sclerosis (MS). The aim of this meta-analysis was to synthesize the available data obtained from 3.0-Tesla (3T) MRI scanners and to explore the relationship between CSCA and scores on the Expanded Disability Status Scale (EDSS).

METHODS

We searched PubMed, Embase, and Web of Science for articles published from the database inception to February 1, 2019. The quality of the articles was assessed according to a quality evaluation checklist which was created based on the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. We conducted a meta-analysis of the correlation between EDSS scores and CSCA at 3T MRI in MS.

RESULTS

Twenty-two eligible studies involving 1933 participants were incorporated into our meta-analysis. Our results demonstrated that CSCA was negatively and moderately correlated with EDSS scores (r_s = -0.42, 95% CI: -0.51 to -0.32; p < 0.0001). Subgroup analyses revealed a weaker correlation in the group of relapsing-remitting multiple sclerosis (RRMS) and clinically isolated syndrome (CIS) (r_s = -0.19, 95% CI: -0.31 to -0.07; p = 0.0029).

CONCLUSIONS

The correlation between CSCA and EDSS scores was significant but moderate. We encourage more studies using reliable and consistent methods to explore whether CSCA is suitable as a predictor for MS progression.

Contribution of normal aging to brain atrophy in MS

Objective

To identify the top brain regions affected by MS-specific atrophy (i.e., atrophy in excess of normal aging) and to test whether normal aging and MS-specific atrophy increase or decrease in these regions with age.

Methods

Six hundred fifty subjects (2,790 MRI time points) were analyzed: 520 subjects with relapse-onset MS from a 5-year prospective cohort with annual standardized 1-mm 3D T1-weighted images (3DT1s; 2,483 MRIs) and 130 healthy controls with longitudinal 3DT1s (307 MRIs). Rates of change in all FreeSurfer regions (v5.3) and Structural Image Evaluation Using Normalization of Atrophy (SIENA) were estimated with mixed-effects models. All FreeSurfer regions were ranked by the MS-specific atrophy slope/standard error ratio (β_{MS × time}/SE_{βMS × time}). In the top regions, age was added as an effect modifier to test whether MS-specific atrophy varied by age.

Results

The top-ranked regions were all gray matter structures. For SIENA, normal aging increased from 0.01%/y at age 30 years to −0.31%/y at age 60 years (−0.11% ± 0.032%/decade, p < 0.01), whereas MS-specific atrophy decreased from −0.38%/y at age 30 years to −0.12%/y at age 60 years (0.09% ± 0.035%/decade, p = 0.01). Similarly, in the thalamus, normal aging increased from −0.15%/y at age 30 years to −0.62%/y at age 60 years (−0.16% ± 0.079%/decade, p < 0.05), and MS-specific atrophy decreased from −0.59%/y at age 30 years to −0.05%/y at age 60 years (0.18% ± 0.08%/decade, p < 0.05). In the putamen and caudate, normal aging and MS-specific atrophy did not vary by age.

Conclusions

For SIENA and thalamic atrophy, the contribution of normal aging increases with age, but does not change in the putamen and caudate. This may have substantial implications to understand the biology of brain atrophy in MS.

MicroRNA-223 protects neurons from degeneration in experimental autoimmune encephalomyelitis

Dysregulation of miRNAs has been observed in many neurodegenerative diseases, including multiple sclerosis. Morquette et al. show that overexpression of miR-223-3p prevents accumulation of axonal damage in a rodent model of multiple sclerosis, in part through regulation of glutamate receptor signalling. Manipulation of miRNA levels may have therapeutic potential.

Lesion activity and chronic demyelination are the major determinants of brain atrophy in MS

Objective

To evaluate the combined effect of lesion activity and pathologic processes occurring in both chronically demyelinated lesions and normal-appearing white matter (NAWM) on brain atrophy in MS.

Methods

Pre- and post-gadolinium T1, fluid attenuation inversion recovery, and diffusion tensor imaging images were acquired from 50 consecutive patients with relapsing-remitting MS (all, but one, on disease-modifying therapy) at baseline and 5 years. Brain atrophy was measured using structural image evaluation, using normalization of atrophy percent brain volume change (PBVC) analysis.

Results

During follow-up, brain volume diminished by 2.0% ± 1.1%. PBVC was not associated with patient age, disease duration, sex, or type of treatment. PBVC moderately correlated with baseline lesion load (r = −0.38, p = 0.016), but demonstrated strong association with new lesion activity (r = −0.63, p < 0.001). Brain atrophy was also strongly linked to the increase of water diffusion within chronic MS lesions (r = −0.62, p < 0.001). In normal-appearing white matter (NAWM), PBVC demonstrated a significant correlation with both baseline and longitudinal increase of demyelination as measured by radial diffusivity (RD, r = −0.44, p = 0.005 and r = −0.35, p = 0.026, respectively). Linear regression analysis explained 62% of the variance in PBVC. It confirmed the major role of new lesion activity (p = 0.002, standardized beta-coefficient −0.42), whereas change in diffusivity inside chronic lesions and NAWM RD at baseline also contributed significantly (p = 0.04 and 0.02, standardized beta-coefficient −0.31 and −0.29, respectively), increasing predictive power of the model by 55%.

Conclusion

In addition to new lesion activity, progressive loss of demyelinated axons in chronic lesions and the degree of demyelination in NAWM significantly contribute to accelerated loss of brain tissue in patients with MS receiving immunomodulatory therapy.

Central nervous system targeted autoimmunity causes regional atrophy: a 9.4T MRI study of the EAE mouse model of Multiple Sclerosis

Atrophy has become a clinically relevant marker of progressive neurodegeneration in multiple sclerosis (MS). To better understand atrophy, mouse models that feature atrophy along with other aspects of MS are needed. The experimental autoimmune encephalomyelitis (EAE) mouse model of MS was used to determine the extent of atrophy in a model of inflammation-associated central nervous system pathology. High-resolution magnetic resonance imaging (MRI) and atlas-based volumetric analysis were performed to measure brain regional volumes in EAE mice. EAE brains were larger at peak clinical disease (days 14–16) compared to controls, with affected regions including the cerebellum, hippocampus, and corpus callosum. Following peak clinical disease, EAE mice exhibited significant loss of volume at chronic long-term disease duration (day 66+). Atrophy was identified in both white and grey matter regions including the cerebral cortex, cerebellum, hippocampus, corpus callosum, basal forebrain, midbrain, optic tract, and colliculus. Histological analysis of the atrophied cortex, cerebellum, and hippocampus showed demyelination, and axonal/neuronal loss. We hypothesize this atrophy could be a result of inflammatory associated neurodegenerative processes, which may also be involved in MS. Using MRI and atlas-based volumetrics, EAE has the potential to be a test bed for treatments aimed at reducing progressive neurological deterioration in MS.

Three-dimensional MRI sequences in MS diagnosis and research

The most recent guidelines for magnetic resonance imaging (MRI) in multiple sclerosis (MS) recommend three-dimensional (3D) MRI sequences over their two-dimensional (2D) counterparts. This development has been made possible by advances in MRI scanner hardware and software. In this article, we review the 3D versions of conventional sequences, including T1-weighted, T2-weighted and fluid-attenuated inversion recovery (FLAIR), as well as more advanced scans, including double inversion recovery (DIR), FLAIR2, FLAIR*, phase-sensitive inversion recovery, and susceptibility weighted imaging (SWI).

Body Mass Index in Multiple Sclerosis modulates ceramide-induced DNA methylation and disease course

BACKGROUND

Multiple Sclerosis (MS) results from genetic predisposition and environmental variables, including elevated Body Mass Index (BMI) in early life. This study addresses the effect of BMI on the epigenome of monocytes and disease course in MS.

METHODS

Fifty-four therapy-naive Relapsing Remitting (RR) MS patients with high and normal BMI received clinical and MRI evaluation. Blood samples were immunophenotyped, and processed for unbiased plasma lipidomic profiling and genome-wide DNA methylation analysis of circulating monocytes. The main findings at baseline were validated in an independent cohort of 91 therapy-naïve RRMS patients. Disease course was evaluated by a two-year longitudinal follow up and mechanistic hypotheses tested in human cell cultures and in animal models of MS.

FINDINGS

Higher monocytic counts and plasma ceramides, and hypermethylation of genes involved in negative regulation of cell proliferation were detected in the high BMI group of MS patients compared to normal BMI. Ceramide treatment of monocytic cell cultures increased proliferation in a dose-dependent manner and was prevented by DNA methylation inhibitors. The high BMI group of MS patients showed a negative correlation between monocytic counts and brain volume. Those subjects at a two-year follow-up showed increased T1 lesion load, increased disease activity, and worsened clinical disability. Lastly, the relationship between body weight, monocytic infiltration, DNA methylation and disease course was validated in mouse models of MS.

INTERPRETATION

High BMI negatively impacts disease course in Multiple Sclerosis by modulating monocyte cell number through ceramide-induced DNA methylation of anti-proliferative genes. FUND: This work was supported by funds from the Friedman Brain Institute, NIH, and Multiple Sclerosis Society.

Association of circulating anti-CD64 IgM levels with favourable long-term clinical outcomes in multiple sclerosis patients

Circulating levels of IgM anti-CD64, an immunosuppressive antibody recently identified in long-term stable multiple sclerosis (MS) patients, were found to fluctuate over time in MS patients. Antibody-positive patients showed a significantly lower annualized relapse rate value as well as reached sustained disability worsening and had a relapse in a significantly longer median time than those without antibody. Disease-modifying therapies (DMTs) only were the covariate influencing both the relapse occurrence and the disability accrual. Serum IgM anti-CD64 levels are associated with maintenance of clinical stability in MS and may be tested as a candidate biomarker predictive of benign course and favourable long-term response to DMTs treatment.

Brain regional volume estimations with NeuroQuant and FIRST: a study in patients with a clinically isolated syndrome

PURPOSE

Brain volume estimates from magnetic resonance images (MRIs) are of great interest in multiple sclerosis, and several automated tools have been developed for this purpose. The goal of this study was to assess the agreement between two tools, NeuroQuant® (NQ) and FMRIB's Integrated Registration Segmentation Tool (FIRST), for estimating overall and regional brain volume in a cohort of patients with a clinically isolated syndrome (CIS). In addition, white matter lesion volume was estimated with NQ and the Lesion Segmentation Toolbox (LST).

METHODS

One hundred fifteen CIS patients were analysed. Structural images were acquired on a 3.0-T system. The volume agreement between methods (by estimation of the intraclass correlation coefficient) was calculated for the right and left thalamus, caudate, putamen, pallidum, hippocampus, and amygdala, as well as for the total intracranial volume and white matter lesion volume.

RESULTS

In general, the estimated volumes were larger by NQ than FIRST, except for the pallidum. Agreement was low (ICC < 0.40) for the smaller structures (amygdala and pallidum) and fair to good (ICC > 0.40) for the remaining ones. Agreement was fair for lesion volume (ICC = 0.61), with NQ estimates lower than LST.

CONCLUSIONS

Agreement between NQ and FIRST brain volume estimates depends on the size of the structure of interest, with larger volumes achieving better agreement. In addition, concordance between the two tools does seem to be dependent on the presence of brain lesions.

A Serial 10-Year Follow-Up Study of Atrophied Brain Lesion Volume and Disability Progression in Patients with Relapsing-Remitting MS

BACKGROUND AND PURPOSE

Disappearance of T2 lesions into CSF spaces is frequently observed in patients with MS. Our aim was to investigate temporal changes of cumulative atrophied brain T2 lesion volume and 10-year confirmed disability progression.

MATERIALS AND METHODS

We studied 176 patients with relapsing-remitting MS who underwent MR imaging at baseline, 6 months, and then yearly for 10 years. Occurrence of new/enlarging T2 lesions, changes in T2 lesion volume, and whole-brain, cortical and ventricle volumes were assessed yearly between baseline and 10 years. Atrophied T2 lesion volume was calculated by combining baseline lesion masks with follow-up CSF partial volume maps. Ten-year confirmed disability progression was confirmed after 48 weeks. ANCOVA detected MR imaging outcome differences in stable (n = 76) and confirmed disability progression (n = 100) groups at different time points; hierarchic regression determined the unique additive variance explained by atrophied T2 lesion volume regarding the association with confirmed disability progression, in addition to other MR imaging metrics. Cox regression investigated the association of early MR imaging outcome changes and time to development of confirmed disability progression.

RESULTS

The separation of stable-versus-confirmed disability progression groups became significant even in the first 6 months for atrophied T2 lesion volume (140% difference, Cohen d = 0.54, P = .004) and remained significant across all time points (P ≤ .007). The hierarchic model, including all other MR imaging outcomes during 10 years predicting confirmed disability progression, improved significantly after adding atrophied T2 lesion volume (R ² = 0.27, R ² change 0.11, P = .009). In Cox regression, atrophied T2 lesion volume in 0-6 months (hazard ratio = 4.23, P = .04) and 0-12 months (hazard ratio = 2.41, P = .022) was the only significant MR imaging predictor of time to confirmed disability progression.

CONCLUSIONS

Atrophied T2 lesion volume is a robust and early marker of disability progression in relapsing-remitting MS.

MRI phenotypes in MS: Longitudinal changes and miRNA signatures

Objective

To classify and immunologically characterize persons with MS based on brain lesions and atrophy and their associated microRNA profiles.

Methods

Cerebral T2-hyperintense lesion volume (T2LV) and brain parenchymal fraction (BPF) were quantified and used to define MRI phenotypes as follows: type I: low T2LV, low atrophy; type II: high T2LV, low atrophy; type III: low T2LV, high atrophy; type IV: high T2LV, high atrophy, in a large cross-sectional cohort (n = 1,088) and a subset with 5-year lngitudinal follow-up (n = 153). Serum miRNAs were assessed on a third MS cohort with 2-year MRI phenotype stability (n = 98).

Results

One-third of the patients had lesion-atrophy dissociation (types II or III) in both the cross-sectional and longitudinal cohorts. At 5 years, all phenotypes had progressive atrophy (p < 0.001), disproportionally in type II (BPF -2.28%). Only type IV worsened in physical disability. Types I and II showed a 5-year MRI phenotype conversion rate of 33% and 46%, whereas III and IV had >90% stability. Type II switched primarily to IV (91%); type I switched primarily to II (47%) or III (37%). Baseline higher age (p = 0.006) and lower BPF (p < 0.001) predicted 5-year phenotype conversion. Each MRI phenotype demonstrated an miRNA signature whose underlying biology implicates blood-brain barrier pathology: hsa.miR.22.3p, hsa.miR.361.5p, and hsa.miR.345.5p were the most valid differentiators of MRI phenotypes.

Conclusions

MRI-defined MS phenotypes show high conversion rates characterized by the continuation of either predominant neurodegeneration or inflammation and support the partial independence of these 2 measures. MicroRNA signatures of these phenotypes suggest a role for blood-brain barrier integrity.

Brain Atrophy Is Associated with Disability Progression in Patients with MS followed in a Clinical Routine

BACKGROUND AND PURPOSE

The assessment of brain atrophy in a clinical routine is not performed routinely in multiple sclerosis. Our aim was to determine the feasibility of brain atrophy measurement and its association with disability progression in patients with MS followed in a clinical routine for 5 years.

MATERIALS AND METHODS

A total of 1815 subjects, 1514 with MS and 137 with clinically isolated syndrome and 164 healthy individuals, were collected retrospectively. Of 11,794 MR imaging brain scans included in the analysis, 8423 MRIs were performed on a 3T, and 3371 MRIs, on a 1.5T scanner. All patients underwent 3D T1WI and T2-FLAIR examinations at all time points of the study. Whole-brain volume changes were measured by percentage brain volume change/normalized brain volume change using SIENA/SIENAX on 3D T1WI and percentage lateral ventricle volume change using NeuroSTREAM on T2-FLAIR.

RESULTS

Percentage brain volume change failed in 36.7% of the subjects; percentage normalized brain volume change, in 19.2%; and percentage lateral ventricle volume change, in 3.3% because of protocol changes, poor scan quality, artifacts, and anatomic variations. Annualized brain volume changes were significantly different between those with MS and healthy individuals for percentage brain volume change (P < .001), percentage normalized brain volume change (P = .002), and percentage lateral ventricle volume change (P = .01). In patients with MS, mixed-effects model analysis showed that disability progression was associated with a 21.9% annualized decrease in percentage brain volume change (P < .001) and normalized brain volume (P = .002) and a 33% increase in lateral ventricle volume (P = .004).

CONCLUSIONS

All brain volume measures differentiated MS and healthy individuals and were associated with disability progression, but the lateral ventricle volume assessment was the most feasible.

Whole brain and deep gray matter atrophy detection over 5 years with 3T MRI in multiple sclerosis using a variety of automated segmentation pipelines

Background

Cerebral atrophy is common in multiple sclerosis (MS) and selectively involves gray matter (GM). Several fully automated methods are available to measure whole brain and regional deep GM (DGM) atrophy from MRI.

Objective

To assess the sensitivity of fully automated MRI segmentation pipelines in detecting brain atrophy in patients with relapsing-remitting (RR) MS and normal controls (NC) over five years.

Methods

Consistent 3D T1-weighted sequences were performed on a 3T GE unit in 16 mildly disabled patients with RRMS and 16 age-matched NC at baseline and five years. All patients received disease-modifying immunotherapy on-study. Images were applied to two pipelines to assess whole brain atrophy [brain parenchymal fraction (BPF) from SPM12; percentage brain volume change (PBVC) from SIENA] and two other pipelines (FSL-FIRST; FreeSurfer) to assess DGM atrophy (thalamus, caudate, globus pallidus, putamen). MRI change was compared by two sample t-tests. Expanded Disability Status Scale (EDSS) and timed 25-foot walk (T25FW) change was compared by repeated measures proportional odds models.

Results

Using FreeSurfer, the MS group had a ~10-fold acceleration in on-study volume loss than NC in the caudate (mean decrease 0.51 vs. 0.05 ml, p = 0.022). In contrast, caudate atrophy was not detected by FSL-FIRST (mean decrease 0.21 vs. 0.12 ml, p = 0.53). None of the other pipelines showed any difference in volume loss between groups, for whole brain or regional DGM atrophy (all p>0.38). The MS group showed on-study stability on EDSS (p = 0.47) but slight worsening of T25FW (p = 0.054).

Conclusions

In this real-world cohort of mildly disabled treated patients with RRMS, we identified ongoing atrophy of the caudate nucleus over five years, despite the lack of any significant whole brain atrophy, compared to healthy controls. The detectability of caudate atrophy was dependent on the MRI segmentation pipeline employed. These findings underscore the increased sensitivity gained when assessing DGM atrophy in monitoring MS.

Brain and retinal atrophy in African-Americans versus Caucasian-Americans with multiple sclerosis: a longitudinal study

On average, African Americans with multiple sclerosis demonstrate higher inflammatory disease activity, faster disability accumulation, greater visual dysfunction, more pronounced brain tissue damage and higher lesion volume loads compared to Caucasian Americans with multiple sclerosis. Neurodegeneration is an important component of multiple sclerosis, which in part accounts for the clinical heterogeneity of the disease. Brain atrophy appears to be widespread, although it is becoming increasingly recognized that regional substructure atrophy may be of greater clinical relevance. Patient race (within the limitations of self-identified ancestry) is regarded as an important contributing factor. However, there is a paucity of studies examining differences in neurodegeneration and brain substructure volumes over time in African Americans relative to Caucasian American patients. Optical coherence tomography is a non-invasive and reliable tool for measuring structural retinal changes. Recent studies support its utility for tracking neurodegeneration and disease progression in vivo in multiple sclerosis. Relative to Caucasian Americans, African American patients have been found to have greater retinal structural injury in the inner retinal layers. Increased thickness of the inner nuclear layer and the presence of microcystoid macular pathology at baseline predict clinical and radiological inflammatory activity, although whether race plays a role in these changes has not been investigated. Similarly, assessment of outer retinal changes according to race in multiple sclerosis remains incompletely characterized. Twenty-two African Americans and 60 matched Caucasian Americans with multiple sclerosis were evaluated with brain MRI, and 116 African Americans and 116 matched Caucasian Americans with multiple sclerosis were monitored with optical coherence tomography over a mean duration of 4.5 years. Mixed-effects linear regression models were used in statistical analyses. Grey matter (-0.9%/year versus -0.5%: P =0.02), white matter (-0.7%/year versus -0.3%: P =0.04) and nuclear thalamic (-1.5%/year versus -0.7%/year: P =0.02) atrophy rates were approximately twice as fast in African Americans. African Americans also exhibited higher proportions of microcystoid macular pathology (12.1% versus 0.9%, P =0.001). Retinal nerve fibre layer (-1.1% versus -0.8%: P =0.02) and ganglion cell+ inner plexiform layer (-0.7%/year versus -0.4%/year: P =0.01) atrophy rates were faster in African versus Caucasian Americans. African Americans on average exhibited more rapid neurodegeneration than Caucasian Americans and had significantly faster brain and retinal tissue loss. These results corroborate the more rapid clinical progression reported to occur, in general, in African Americans with multiple sclerosis and support the need for future studies involving African Americans in order to identify individual differences in treatment responses in multiple sclerosis.

Inhibiting repulsive guidance molecule-a suppresses secondary progression in mouse models of multiple sclerosis

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system that is characterized by motor deficits, fatigue, pain, cognitive impairment, and sensory and visual dysfunction. Secondary progressive multiple sclerosis (SPMS) is a progressive form of MS that develops from relapsing-remitting MS. Repulsive guidance molecule-a (RGMa) has diverse functions, including axon growth inhibition and immune regulation. Here, we show inhibiting RGMa had therapeutic effects in mouse models of SPMS. We induced experimental autoimmune encephalomyelitis in nonobese diabetic mice (NOD-EAE mice) and treated them with humanized anti-RGMa monoclonal antibody. This treatment significantly suppressed secondary progression of disease and inflammation, demyelination and axonal degeneration. In addition, treatment with anti-RGMa antibody promoted the growth of corticospinal tracts and motor recovery in targeted EAE mice with inflammatory lesions in the spinal cord. Collectively, these results show that a humanized anti-RGMa antibody has therapeutic effects in mouse models of SPMS.