Association Between Thoracic Spinal Cord Gray Matter Atrophy and Disability in Multiple Sclerosis

Management of multiple sclerosis in older adults: review of current evidence and future perspectives

IMPORTANCE

The prevalence of multiple sclerosis (MS) and aging MS patients is increasing worldwide. There is a need to better understand this MS sub-population, which historically is underrepresented in the literature. This narrative review examines the evolving demographics, disease course, and treatments for older adults with MS (OAMS) to address current knowledge gaps and highlight areas critical for future research.

OBSERVATIONS

OAMS populations require special consideration by clinicians. Older individuals have different care needs than individuals with adult onset MS who are mid-life or younger. Comorbidities, an aging immune system, increasing neurodegeneration, decreasing neurologic reserve, changing benefit/risk relationship for disease modifying therapies (DMTs), and wellness require special attention to provide holistic comprehensive care. Active areas of research include potential cessation of DMTs and novel disease targets.

CONCLUSIONS AND RELEVANCE

This review highlights both the current knowledge and information gaps in the literature that are critical to understanding and properly managing OAMS. The aims are to inform MS clinicians in their current practice, as well as inspire future studies which are critical to providing quality and evidence-based care for OAMS.

Recent Advances in Diagnostic, Prognostic, and Disease-Monitoring Biomarkers in Multiple Sclerosis

Multiple sclerosis (MS) is a highly heterogeneous disease. Currently, a combination of clinical features, MRI, and cerebrospinal fluid markers are used in clinical practice for diagnosis and treatment decisions. In recent years, there has been considerable effort to develop novel biomarkers that better reflect the pathologic substrates of the disease to aid in diagnosis and early prognosis, evaluation of ongoing inflammatory activity, detection and monitoring of disease progression, prediction of treatment response, and monitoring of disease-modifying treatment safety. In this review, the authors provide an overview of promising recent developments in diagnostic, prognostic, and disease-monitoring/treatment-response biomarkers in MS.

Feasibility of diffusion kurtosis imaging in evaluating cervical spinal cord injury in multiple sclerosis

This research aimed to assess gray matter (GM), white matter (WM), lesions of multiple sclerosis (MS) and the therapeutic effect using diffusion kurtosis imaging (DKI). From January 2018 to October 2019, 78 subjects (48 of MS and 30 of health) perform routine MR scan and DKI of cervical spinal cord. The MS patients were divided into 2 groups according to the presence or absence of T2 hyperintensity. DKI-metrics were measured in the lesions, normal-appearing GM and WM. Significant differences were detected in DKI metrics between MS and healthy (P < .05) and between patients with cervical spinal cord T2-hyperintense and without T2-hyperintense (P < .001). Compared to healthy, GM-mean kurtosis (MK), GM-radial kurtosis, and WM-fractional anisotropy, WM-axial diffusion were statistically reduced in patients without T2-hyperintense (P < .05). Significant differences were observed in DKI metrics between patients with T2-hyperintense after therapy (P < .05), as well as GM-MK and WM-fractional anisotropy, WM-axial diffusion in patients without T2-hyperintense (P < .05); Expanded Disability Status Scale was correlated with MK values, as well as Expanded Disability Status Scale scores and MK values after therapy. Our results indicate that DKI-metrics can detect and quantitatively evaluate the changes in cervical spinal cord micropathological structure.

Mapping the relationship of white matter lesions to depression in multiple sclerosis

Importance

Multiple sclerosis (MS) is an immune-mediated neurological disorder that affects nearly one million people in the United States. Up to 50% of patients with MS experience depression.

Objective

To investigate how white matter network disruption is related to depression in MS.

Design

Retrospective case-control study of participants who received research-quality 3-tesla neuroimaging as part of MS clinical care from 2010-2018. Analyses were performed from May 1 to September 30, 2022.

Setting

Single-center academic medical specialty MS clinic.

Participants

Participants with MS were identified via the electronic health record (EHR). All participants were diagnosed by an MS specialist and completed research-quality MRI at 3T. After excluding participants with poor image quality, 783 were included. Inclusion in the depression group (MS+Depression) required either: 1) ICD-10 depression diagnosis (F32-F34.*); 2) prescription of antidepressant medication; or 3) screening positive via Patient Health Questionnaire-2 (PHQ-2) or -9 (PHQ-9). Age- and sex-matched nondepressed comparators (MS-Depression) included persons with no depression diagnosis, no psychiatric medications, and were asymptomatic on PHQ-2/9.

Exposure

Depression diagnosis.

Main Outcomes and Measures

We first evaluated if lesions were preferentially located within the depression network compared to other brain regions. Next, we examined if MS+Depression patients had greater lesion burden, and if this was driven by lesions specifically in the depression network. Outcome measures were the burden of lesions (e.g., impacted fascicles) within a network and across the brain. Secondary measures included between-diagnosis lesion burden, stratified by brain network. Linear mixed-effects models were employed.

Results

Three hundred-eighty participants met inclusion criteria, (232 MS+Depression: age[SD]=49[12], %females=86; 148 MS-Depression: age[SD]=47[13], %females=79). MS lesions preferentially affected fascicles within versus outside the depression network (β=0.09, 95% CI=0.08-0.10, P<0.001). MS+Depression had more white matter lesion burden (β=0.06, 95% CI=0.01-0.10, P=0.015); this was driven by lesions within the depression network (β=0.02, 95% CI 0.003-0.040, P=0.020).

Conclusions and Relevance

We provide new evidence supporting a relationship between white matter lesions and depression in MS. MS lesions disproportionately impacted fascicles in the depression network. MS+Depression had more disease than MS-Depression, which was driven by disease within the depression network. Future studies relating lesion location to personalized depression interventions are warranted.

Association of daily physical activity with brain volumes and cervical spinal cord areas in multiple sclerosis

BACKGROUND

Remote activity monitoring has the potential to evaluate real-world, motor function, and disability at home. The relationships of daily physical activity with spinal cord white matter and gray matter (GM) areas, multiple sclerosis (MS) disability and leg function, are unknown.

OBJECTIVE

Evaluate the association of structural central nervous system pathology with ambulatory disability.

METHODS

Fifty adults with progressive or relapsing MS with motor disability who could walk >2 minutes were assessed using clinician-evaluated, patient-reported outcomes, and quantitative brain and spinal cord magnetic resonance imaging (MRI) measures. Fitbit Flex2, worn on the non-dominant wrist, remotely assessed activity over 30 days. Univariate and multivariate analyses were performed to assess correlations between physical activity and other disability metrics.

RESULTS

Mean age was 53.3 years and median Expanded Disability Status Scale (EDSS) was 4.0. Average daily step counts (STEPS) were highly correlated with EDSS and walking measures. Greater STEPS were significantly correlated with greater C2-C3 spinal cord GM areas (ρ = 0.39, p = 0.04), total cord area (TCA; ρ = 0.35, p = 0.04), and cortical GM volume (ρ = 0.32, p = 0.04).

CONCLUSION

These results provide preliminary evidence that spinal cord GM area is a neuroanatomical substrate associated with STEPS. STEPS could serve as a proxy to alert clinicians and researchers to possible changes in structural nervous system pathology.

Longitudinal assessment of cervical spinal cord compartments in multiple sclerosis

BACKGROUND

Although cervical spinal cord (cSC) area is an established biomarker in MS, there is currently a lack of longitudinal assessments of cSC gray and white matter areas.

OBJECTIVE

We conducted an explorative analysis of longitudinal changes of cSC gray and white matter areas in MS patients.

METHODS

65 MS patients (33 relapsing-remitting; 20 secondary progressive and 12 primary progressive) and 20 healthy controls (HC) received clinical and upper cSC MRI assessments over 1.10±0.28 years. cSC compartments were quantified on MRI using the novel averaged magnetization inversion recovery acquisitions sequence (in-plane resolution=0.67 × 0.67mm²), and in-house developed post-processing methods. Patients were stratified regarding clinical progression.

RESULTS

Patients with clinical progression showed faster reduction of cSC areas over time at the level of cSC enlargement (approximate vertebral level C4-C5) compared to stable patients (p<0.05). In addition, when compared to the rostral-cSC (approximate vertebral level C2-C3), a preferential reduction of cSC and white matter areas over time at the level of cSC enlargement (p<0.05 and p<0.01, respectively) was demonstrated only in patients with clinical progression, but not in stable MS patients and HC. Compared to HC, MS patients showed comparable changes over time in all cSC compartments.

CONCLUSIONS

MS patients with clinical disease progression demonstrate subtle signs of a more pronounced tissue loss at the level of cSC enlargement. Future studies should consider larger sample sizes and more extended observation periods.

Fully Automatic Method for Reliable Spinal Cord Compartment Segmentation in Multiple Sclerosis

BACKGROUND AND PURPOSE

Fully automatic quantification methods of spinal cord compartments are needed to study pathologic changes of the spinal cord GM and WM in MS in vivo. We propose a novel method for automatic spinal cord compartment segmentation (SCORE) in patients with MS.

MATERIALS AND METHODS

The cervical spinal cords of 24 patients with MS and 24 sex- and age-matched healthy controls were scanned on a 3T MR imaging system, including an averaged magnetization inversion recovery acquisition sequence. Three experienced raters manually segmented the spinal cord GM and WM, anterior and posterior horns, gray commissure, and MS lesions. Subsequently, manual segmentations were used to train neural segmentation networks of spinal cord compartments with multidimensional gated recurrent units in a 3-fold cross-validation fashion. Total intracranial volumes were quantified using FreeSurfer.

RESULTS

The intra- and intersession reproducibility of SCORE was high in all spinal cord compartments (eg, mean relative SD of GM and WM: ≤ 3.50% and ≤1.47%, respectively) and was better than manual segmentations (all P < .001). The accuracy of SCORE compared with manual segmentations was excellent, both in healthy controls and in patients with MS (Dice similarity coefficients of GM and WM: ≥ 0.84 and ≥0.92, respectively). Patients with MS had lower total WM areas (P < .05), and total anterior horn areas (P < .01 respectively), as measured with SCORE.

CONCLUSIONS

We demonstrate a novel, reliable quantification method for spinal cord tissue segmentation in healthy controls and patients with MS and other neurologic disorders affecting the spinal cord. Patients with MS have reduced areas in specific spinal cord tissue compartments, which may be used as MS biomarkers.

Cervical spinal cord atrophy in amyotrophic lateral sclerosis across disease stages

OBJECTIVE

Spinal cord degeneration is a hallmark of amyotrophic lateral sclerosis. The assessment of gray matter and white matter cervical spinal cord atrophy across clinical stages defined using the King's staging system could advance the understanding of amyotrophic lateral sclerosis progression.

METHODS

We assessed the in vivo spatial pattern of gray and white matter atrophy along cervical spinal cord (C2 to C6 segments) using 2D phase-sensitive inversion recovery imaging in a cohort of 44 amyotrophic lateral sclerosis patients, evaluating its change across the King's stages and the correlation with disability scored by the amyotrophic lateral sclerosis functional rating scale revised (ALSFRS-R) and disease duration. A mathematical model inferring the potential onset of cervical gray matter atrophy was developed.

RESULTS

In amyotrophic lateral sclerosis patients at King's stage 1, significant cervical spinal cord alterations were mainly identified in gray matter, whereas they involved both gray and white matter in patients at King's stage ≥ 2. Gray and white matter areas correlated with clinical disability at all cervical segments. C3-C4 level was the segment showing early gray matter atrophy starting about 7 to 20 months before symptom onset according to our model.

INTERPRETATION

Our findings suggest that cervical spinal cord atrophy spreads from gray to white matter across King's stages in amyotrophic lateral sclerosis, making spinal cord magnetic resonance imaging an in vivo assessment tool to measure the progression of the disease.

Myelitis features and outcomes in CNS demyelinating disorders: Comparison between multiple sclerosis, MOGAD, and AQP4-IgG-positive NMOSD

Inflammatory myelopathies can manifest with a combination of motor, sensory and autonomic dysfunction of variable severity. Depending on the underlying etiology, the episodes of myelitis can recur, often leading to irreversible spinal cord damage and major long-term disability. Three main demyelinating disorders of the central nervous system, namely multiple sclerosis (MS), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorders (AQP4+NMOSD) and myelin oligodendrocyte glycoprotein-IgG associated disease (MOGAD), can induce spinal cord inflammation through different pathogenic mechanisms, resulting in a more or less profound disruption of spinal cord integrity. This ultimately translates into distinctive clinical-MRI features, as well as distinct patterns of disability accrual, with a step-wise worsening of neurological function in MOGAD and AQP4+NMOSD, and progressive disability accrual in MS. Early recognition of the specific etiologies of demyelinating myelitis and initiation of the appropriate treatment is crucial to improve outcome. In this review article we summarize and compare the clinical and imaging features of spinal cord involvement in these three demyelinating disorders, both during the acute phase and over time, and outline the current knowledge on the expected patterns of disability accrual and outcomes. We also discuss the potential implications of these observations for patient management and counseling.

Advanced spinal cord MRI in multiple sclerosis: Current techniques and future directions

Spinal cord magnetic resonance imaging (MRI) has a central role in multiple sclerosis (MS) clinical practice for diagnosis and disease monitoring. Advanced MRI sequences capable of visualizing and quantifying tissue macro- and microstructure and reflecting different pathological disease processes have been used in MS research; however, the spinal cord remains under-explored, partly due to technical obstacles inherent to imaging this structure. We propose that the study of the spinal cord merits equal ambition in overcoming technical challenges, and that there is much information to be exploited to make valuable contributions to our understanding of MS. We present a narrative review on the latest progress in advanced spinal cord MRI in MS, covering in the first part structural, functional, metabolic and vascular imaging methods. We focus on recent studies of MS and those making significant technical steps, noting the challenges that remain to be addressed and what stands to be gained from such advances. Throughout we also refer to other works that presend more in-depth review on specific themes. In the second part, we present several topics that, in our view, hold particular potential. The need for better imaging of gray matter is discussed. We stress the importance of developing imaging beyond the cervical spinal cord, and explore the use of ultra-high field MRI. Finally, some recommendations are given for future research, from study design to newer developments in analysis, and the need for harmonization of sequences and methods within the field. This review is aimed at researchers and clinicians with an interest in gaining an overview of the current state of advanced MRI research in this field and what is primed to be the future of spinal cord imaging in MS research.

Epidemiology and Pathophysiology of Multiple Sclerosis

PURPOSE OF REVIEW

This article provides an overview of genetic, environmental, and lifestyle risk factors affecting the disease course of multiple sclerosis (MS) and reviews the pathophysiologic characteristics of both relapsing and progressive MS.

RECENT FINDINGS

The prevalence of MS has increased in recent decades, and costs of care for patients with MS have risen dramatically. Black, Asian, and Hispanic individuals may be at risk for more severe MS-related disability. Multiple genetic MS risk factors have been identified. Factors such as low vitamin D levels and a history of Epstein-Barr virus, smoking, and obesity, especially during childhood, also influence MS risk. Traditionally thought to be a T-cell-mediated disease, recent research has highlighted the additional roles of B cells and microglia in both relapsing and progressive MS.

SUMMARY

Complex interactions between genetic, environmental, and lifestyle factors affect the risk for MS as well as the disease course. People of color have historically been underrepresented in both MS clinical trials and literature, but current research is attempting to better clarify unique considerations in these groups. MS pathology consists of the focal inflammatory lesions that have been well characterized in relapsing MS, as well as a more widespread neurodegenerative component that is posited to drive progressive disease. Recent advances in characterization of both the inflammatory and neurodegenerative aspects of MS pathophysiology have yielded potential targets for future therapeutic options.

Deformation-based morphometry identifies deep brain structures protected by ocrelizumab

BACKGROUND

Despite advancements in treatments for multiple sclerosis, insidious disease progression remains an area of unmet medical need, for which atrophy-based biomarkers may help better characterize the progressive biology.

METHODS

We developed and applied a method of longitudinal deformation-based morphometry to provide voxel-level assessments of brain volume changes and identified brain regions that were significantly impacted by disease-modifying therapy.

RESULTS

Using brain MRI data from two identically designed pivotal trials of relapsing multiple sclerosis (total N = 1483), we identified multiple deep brain regions, including the thalamus and brainstem, where volume loss over time was reduced by ocrelizumab (p < 0.05), a humanized anti-CD20 + monoclonal antibody approved for the treatment of multiple sclerosis. Additionally, identified brainstem shrinkage, as well as brain ventricle expansion, was associated with a greater risk for confirmed disability progression (p < 0.05).

CONCLUSIONS

The identification of deep brain structures has a strong implication for developing new biomarkers of brain atrophy reduction to advance drug development for multiple sclerosis, which has an increasing focus on targeting the progressive biology.

Multiple sclerosis lesions and atrophy in the spinal cord: Distribution across vertebral levels and correlation with disability

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In multiple sclerosis, spinal cord lesions and atrophy are measurable by whole spinal cord MRI with axial and sagittal coverage in a large patient cohort and in healthy control subjects.

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Spinal cord lesions and atrophy are accentuated in the cervical enlargement.

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They have already developed at the stage of RRMS and continue developing in a clinically meaningful way at later stages.

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Yet they remain largely independent.

Background

The vast majority of magnetic resonance imaging (MRI) studies on multiple sclerosis (MS) covered the spinal cord (SC), if at all, incompletely.

Objective

To assess SC involvement in MS, as detectable by whole SC MRI, with regard to distribution across vertebral levels and relation to clinical phenotypes and disability.

Methods

We investigated SC MRI with sagittal and axial coverage. Analyzed were brain and SC MRI scans of 17 healthy controls (HC) and of 370 patients with either clinically isolated syndrome (CIS, 27), relapsing remitting MS (RRMS, 303) or progressive MS (PMS, 40). Across vertebral levels, cross-sectional areas were semiautomatically segmented, and lesions manually delineated.

Results

The frequency of SC lesions was highest at the level C3-4. The volume of SC lesions increased from CIS to RRMS, and from RRMS to PMS whereas lesion distribution across SC levels did not differ. SC atrophy was demonstrated in RRMS and, to a higher degree, in PMS; apart from an accentuation at the level C3-4, it was evenly distributed across SC levels. SC lesions and atrophy volume were not correlated with each other and were independently associated with disability.

Conclusion

SC lesions and atrophy already exist at the stage of RRMS in the whole SC with an accentuation in the cervical enlargement; SC lesions and atrophy are more pronounced in the stage of PMS. Both contribute to the clinical picture but are largely independent.

The course of cervical spinal cord atrophy rate and its relationship with NEDA in relapsing remitting multiple sclerosis

This study aimed to compare the annualized segmental cervical spinal cord atrophy rate (ASCAR) in the early and late stages of relapsing remitting multiple sclerosis (RRMS), and to investigate the relationship between ASCAR and no evidence of disease activity (NEDA) in RRMS. Participants in this study included early stage MS (EMSg) patients, late stage MS (LMSg) patients, and healthy controls. All of the included participants (n = 175 subjects) were followed up for 14 months, and an MRI was performed on each participant at the beginning and at the end of the study. Cervical spinal cord average segmental area (CSCA) was measured by a semi-automated method, and ASCAR (mm²/year) was calculated. Data from the EMSg (n = 81 subjects) and LMSg (n = 94 subjects) patient groups were compared with each other and with the control group (n = 43 subjects). Examination of the initial CSCA values revealed that the baseline CSCA of the control group was larger than that of the EMSg (p < 0.001), and the baseline CSCA of the EMSg was larger than that of the LMSg (p < 0.001). The ASCAR of the control group, LMSg, and EMSg were 0.48, 0.93, and 1.81 mm² (p < 0.001), respectively. Regression analysis revealed that disability increase was associated with ASCAR, while MRI activity and relapse presence were unrelated to ASCAR. In both patient groups, ASCAR was slower in those who fulfilled NEDA but this relationship was not significant. Cervical spinal cord atrophy progression over time occurs at a greater rate in the early stages of RRMS disease compared to the late stages. ASCAR was unrelated to MRI activity and relapse, which are clinical markers of acute inflammation.

Prognostic Value of Serum Neurofilament Light Chain for Disease Activity and Worsening in Patients With Relapsing Multiple Sclerosis: Results From the Phase 3 ASCLEPIOS I and II Trials

Objective

This study aims to confirm the prognostic value of baseline serum neurofilament light chain (sNfL) for on-study disease activity and worsening in patients with relapsing MS (RMS).

Background

Previous post-hoc studies suggested that sNfL could be a prognostic biomarker in RMS. In the phase 3 ASCLEPIOS I/II trials in which ofatumumab demonstrated better efficacy outcomes than teriflunomide, treatment with ofatumumab also led to significantly reduced sNfL levels compared to teriflunomide treatment.

Design/Methods

In this study, we report protocol-planned analyses from the pooled ASCLEPIOS I/II trials (N=1882). Per protocol, patients were stratified by median baseline sNfL levels (9.3 pg/ml) into high (>median) and low (≤median) categories to prognosticate: annualized rate of new/enlarging T2 (neT2) lesions in year 1 and 2, annualized relapse rate, annual percentage change in whole brain (WB) and regional brain volume [thalamus, white matter (WM), cortical gray matter (cGM)], and disability outcomes. Similar analyses were performed for the recently diagnosed (within 3 years), treatment-naive patients (no prior disease-modifying therapy) subgroup.

Results

High versus low sNfL at baseline was prognostic of increased on-study T2 lesion formation at year 1 (relative increase: ofatumumab +158%; teriflunomide +69%, both p<0.001), which persisted in year 2 (+65%, p=0.124; +46%, p=0.003); of higher annual percentage change of WB volume (ofatumumab, −0.32% vs. −0.24%, p=0.044, and teriflunomide, −0.43% vs. −0.29%, p=0.002), thalamic volume (−0.56% vs. −0.31%, p=0.047 and −0.94% vs. −0.49%, p<0.001), and WM volume (−0.30% vs. −0.19%, p=0.083 and −0.38% vs. −0.18%, p=0.003) but not of cGM volume (−0.39% vs. −0.32%, p=0.337 and −0.49% vs. −0.46%, p=0.563). A single sNfL assessment at baseline was not prognostic for on-study relapses or disability worsening. Results were similar in the subgroup of recently diagnosed, treatment-naive patients.

Conclusion

This study confirms that baseline sNfL levels are prognostic of future on-study lesion formation and whole brain and regional atrophy in all RMS patients, including recently diagnosed, treatment-naive patients.

Multiple sclerosis impairment scale and brain MRI in secondary progressive multiple sclerosis

OBJECTIVE

To examine the Multiple Sclerosis Impairment Scale (MSIS) in secondary progressive MS (SPMS) in relation to the Expanded Disability Status Scale (EDSS), magnetic resonance imaging (MRI) outcomes, and mobility.

METHODS

In this observational single-center study, 68 secondary progressive multiple sclerosis (SPMS) patients were examined by MSIS, EDSS, functional mobility tests of upper/lower extremities, and multimodal MRI. Participants had EDSS ≥3.5, a decline in daily activities over the last year unrelated to relapses, and/or 6-month confirmed disability progression.

RESULTS

Mean disease duration was 23.1 ± 8.3 years and mean age 54.4 ± 8.1 years. MSIS, EDSS, and their corresponding motor, cerebellar, and sensory subscores correlated (p < .0001). Motor subscores of MSIS correlated stronger with Timed-25-Foot-Walk (T25FW) than pyramidal functional system score (FSS) (p = .03), but EDSS had a stronger correlation to T25FW than the total MSIS score (p = .01). MSIS cerebellar subscore correlated stronger with 9-Hole Peg Test (9-HPT) than cerebellar FSS (p = .04). The sensory MSIS subscore also showed correlation with 9-HPT in contrast to sensory FSS (p = .006). MSIS subscores had stronger correlations with MRI volumetry measures than FSS scores (lesion volume and putamen, thalamus, corpus callosum volumetry, p = .0001-0.0017).

CONCLUSION

In patients with SPMS, MSIS correlated with functional motor tests. MSIS showed stronger correlations with atrophy of central nervous system areas, and may be more sensitive to scale cerebellar and sensory function than EDSS.

Spinal Cord Gray Matter Atrophy is associated with functional decline in Post-Polio Syndrome

Objective

To determine if patients with post‐polio syndrome (PPS) show spinal cord gray matter (SCGM) atrophy and to assess associations between SCGM atrophy, muscle strength and patient‐reported functional decline.

Methods

Twenty patients diagnosed with PPS (March of Dimes criteria) and 20 age‐ and sex‐matched healthy controls (HC) underwent 3T axial 2D‐rAMIRA magnetic resonance imaging at the intervertebral disc levels C2/C3–C6/C7, T9/T10 and the lumbar enlargement level (T_max) (0.5 × 0.5 mm² in‐plane resolution). SCGM areas were segmented manually by two independent raters. Muscle strength, self‐reported fatigue, depression and pain measures were assessed.

Results

Post‐polio syndrome patients showed significantly and preferentially reduced SCGM areas at C2/C3 (p = 0.048), C3/C4 (p = 0.001), C4/C5 (p < 0.001), C5/C6 (p = 0.004) and T_max (p = 0.041) compared to HC. SCGM areas were significantly associated with muscle strength in corresponding myotomes even after adjustment for fatigue, pain and depression. SCGM area_Tmax together with age and sex explained 68% of ankle dorsiflexion strength variance. No associations were found with age at or time since infection. Patients reporting PPS‐related decline in arm function showed significant cervical SCGM atrophy compared to stable patients adjusted for initial disease severity.

Conclusions

Patients with PPS show significant SCGM atrophy that correlates with muscle strength and is associated with PPS‐related functional decline. Our findings suggest a secondary neurodegenerative process underlying SCGM atrophy in PPS that is not explained by aging or residua of the initial infection alone. Confirmation by longitudinal studies is needed. The described imaging methodology is promising for developing novel imaging surrogates for SCGM diseases.

Design and Validation of an Expanded Disability Status Scale Model in Multiple Sclerosis

INTRODUCTION

We aimed to develop and validate an Expanded Disability Status Scale (EDSS) model through clinical, optical coherence tomography (OCT), and magnetic resonance imaging (MRI) measures.

METHODS

Sixty-four multiple sclerosis (MS) patients underwent peripapillary retinal nerve fiber layer and segmented macular layers evaluation through OCT (Spectralis, Heidelberg Engineering). Brain parenchymal fraction was quantified through Freesurfer, while cervical spinal cord (SC) volume was assessed manually guided by Spinal Cord Toolbox software analysis. EDSS, neuroradiological, and OCT assessment were carried out within 3 months. OCT parameters were calculated as the average of both nonoptic neuritis (ON) eyes, and in case the patient had previous ON, the value of the fellow non-ON eye was taken. Brain lesion volume, sex, age, disease duration, and history of disease-modifying treatment (1st or 2nd line disease-modifying treatments) were tested as covariables of the EDSS score.

RESULTS

EDSS values correlated with patient's age (r = 0.543, p = 0.001), SC volume (r = -0.301, p = 0.034), and ganglion cell layer (GCL, r = -0.354, p = 0.012). Using these correlations, an ordinal regression model to express probability of diverse EDSS scores were designed, the highest of which was the most probable (Nagelkerke R2 = 43.3%). Using EDSS cutoff point of 4.0 in a dichotomous model, compared to a cutoff of 2.0, permits the inclusion of GCL as a disability predictor, in addition to age and SC.

CONCLUSIONS

MS disability measured through EDSS is an age-dependent magnitude that is partly conditioned by SC and GCL. Further studies assessing paraclinical disability predictors are needed.

Early predictors of conversion to secondary progressive multiple sclerosis

BACKGROUND

We conducted this study to estimated the time of conversion from relapsing-remitting MS (RRMS) to SPMS and its early predictor factors.

METHODS

In this retrospective study, demographic, clinical, and imaging data from MS patients at diagnosis were extracted. Cox proportional hazards model was used to assess the association between various baseline characteristics and conversion to SPMS. We also assessed the association brtween escalation and early intensive therapy approaches with transition to progressive phase.

RESULTS

Out of 1903 patients with RRMS at baseline, 293 (15.4%) patients progressed to SPMS during follow-up. The estimated number of patients converted to SPMS was 10% at 10-years, 50% at 20-years, and 93% at 30-years. On multivariate Cox regression analysis older age at onset (HR: 1.067, 95%CI: 1.048-1.085, p < 0.001), smoking (HR: 2.120, 95%CI: 1.203-3.736, p = 0.009), higher EDSS at onset (HR: 1.199, 95%CI: 1.109-1.295, p < 0.001), motor dysfunction (HR: 2.470, 95%CI: 1.605-3.800, p < 0.001), cerebellar dysfunction (HR: 3.096, 95%CI: 1.840-5.211, p < 0.001), and presence of lesions in spinal cord (HR: 0.573, 95%CI: 0.297-0.989, p = 0.042) increased the risk of conversion from RRMS to SPMS. No significant difference between escalation and EIT groups in the risk of transition to progressive phase (weighted HR = 1.438; 95% CI: 0.963, 2.147; p = 0.076) was found.

CONCLUSION

Our data support previous observations that smoking is a modifiable risk factor for secondary progressive MS and confirms that spinal cord involvement, age, and more severe disease at onset are prognostic factors for converting to secondary progressive MS.

Multimodal Evoked Potentials as Candidate Prognostic and Response Biomarkers in Clinical Trials of Multiple Sclerosis

SUMMARY

Evoked potentials (EPs) measure quantitatively and objectively the alterations of central signal propagation in multiple sclerosis and have long been used for diagnosis. More recently, their utility for prognosis has been demonstrated in several studies, summarizing multiple EP modalities in a single score. In particular, visual, somatosensory, and motor EPs are useful because of their sensitivity to pathology in the frequently affected optic nerve, somatosensory tract, and pyramidal system. Quantitative EP scores show higher sensitivity to change than clinical assessment and may be used to monitor disease progression. Visual EP and the visual system have served as a model to study remyelinating therapies in the setting of acute and chronic optic neuritis. This review presents rationale and evidence for using multimodal EP as prognostic and response biomarkers in clinical trials, targeting remyelination or halting disease progression in multiple sclerosis.

Secondary Progressive Multiple Sclerosis: New Insights

In most cases, multiple sclerosis (MS) begins with a relapsing-remitting course followed by insidious disability worsening that is independent from clinically apparent relapses and is termed secondary progressive MS (SMPS). Major differences exist between relapsing-remitting MS (RRMS) and SPMS, especially regarding therapeutic response to treatment. This review provides an overview of the pathology, differentiation, and challenges in the diagnosis and treatment of SPMS. We emphasize the criticality of conversion from a relapsing-remitting to a secondary progressive disease course not only because such conversion is evidence of disability progression, but also because, until recently, treatments that effectively reduced disability progression in relapsing MS were not proven to be effective in SPMS. Clear clinical, imaging, immunologic, or pathologic criteria marking the transition from RRMS to SPMS have not yet been established. Early identification of SPMS will require tools that, together with the use of appropriate treatments, may result in better long-term outcomes for the population of patients with SPMS.

Cervical and thoracic cord atrophy in multiple sclerosis phenotypes: Quantification and correlation with clinical disability

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Spinal cord atrophy is prevalent across multiple sclerosis phenotypes.

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It correlates with disability, especially in relapsing-remitting patients.

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This correlation can be demonstrated both cross-sectionally and longitudinally.

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Cervical atrophy is highly associated with disability and disease progression.

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Thoracic atrophy contributes to improved correlation and radiological subgrouping.

Objective

We sought to characterize spinal cord atrophy along the entire spinal cord in the major multiple sclerosis (MS) phenotypes, and evaluate its correlation with clinical disability.

Methods

Axial T₁-weighted images were automatically reformatted at each point along the cord. Spinal cord cross‐sectional area (SCCSA) were calculated from C1-T10 vertebral body levels and profile plots were compared across phenotypes. Average values from C2-3, C4-5, and T4-9 regions were compared across phenotypes and correlated with clinical scores, and then categorized as atrophic/normal based on z-scores derived from controls, to compare clinical scores between subgroups. In a subset of relapsing-remitting cases with longitudinal scans these regions were compared to change in clinical scores.

Results

The cross-sectional study consisted of 149 adults diagnosed with relapsing-remitting MS (RRMS), 49 with secondary-progressive MS (SPMS), 58 with primary-progressive MS (PPMS) and 48 controls. The longitudinal study included 78 RRMS cases. Compared to controls, all MS groups had smaller average regions except RRMS in T4-9 region. In all MS groups, SCCSA from all regions, particularly the cervical cord, correlated with most clinical measures. In the RRMS cohort, 22% of cases had at least one atrophic region, whereas in progressive MS the rate was almost 70%. Longitudinal analysis showed correlation between clinical disability and cervical cord thinning.

Conclusions

Spinal cord atrophy was prevalent across MS phenotypes, with regional measures from the RRMS cohort and the progressive cohort, including SPMS and PPMS, being correlated with disability. Longitudinal changes in the spinal cord were documented in RRMS cases, making it a potential marker for disease progression. While cervical SCCSA correlated with most disability and progression measures, inclusion of thoracic measurements improved this correlation and allowed for better subgrouping of spinal cord phenotypes. Cord atrophy is an important and easily obtainable imaging marker of clinical and sub-clinical progression in all MS phenotypes, and such measures can play a key role in patient selection for clinical trials.

Quantitative Proteomics-Based Blood-Brain Barrier Study

From the viewpoint of drug discovery, it is an important issue to elucidate the drug permeability at the human central nervous system (CNS) barriers and the molecular mechanisms in the cells forming CNS barriers especially during CNS diseases. I introduced quantitative proteomics techniques into the blood-brain barrier (BBB) study, then quantitatively investigated the transport system at the human BBB and clarified the quantitative differences in protein expression levels and functions of transporters and receptors between animals and humans, or in vitro and in vivo. Based on the difference in the absolute expression level of transporters between in vitro and in vivo, I demonstrated that the drug efflux activity of P-glycoprotein (P-gp) at in vivo BBB can be accurately reconstructed from the in vitro system, not only in mouse models but also monkeys similar to humans and pathological conditions. Furthermore, I discovered Claudin-11 as another tight junction molecule expressed at the CNS barriers, and clarified that it contributes to the disruption of the CNS barriers in multiple sclerosis. Furthermore, it was also elucidated that the P-gp dysfunction causes excessive brain entry of glucocorticoid which causes a nerve damage in cerebral infarct, and it can be suppressed by targeting Abl/Src kinases. These suggest that targeting the tight junctions and transporters, which are important molecules at the CNS barriers, would potentially lead to the treatment of CNS diseases. In this review, I would like to introduce a new CNS barrier study opened by quantitative proteomics research.

Diagnosis of Progressive Multiple Sclerosis From the Imaging Perspective: A Review

Importance

Although magnetic resonance imaging (MRI) is useful for monitoring disease dissemination in space and over time and excluding multiple sclerosis (MS) mimics, there has been less application of MRI to progressive MS, including diagnosing primary progressive (PP) MS and identifying patients with relapsing-remitting (RR) MS who are at risk of developing secondary progressive (SP) MS. This review addresses clinical application of MRI for both diagnosis and prognosis of progressive MS.

Observations

Although nonspecific, some spinal cord imaging features (diffuse abnormalities and lesions involving gray matter [GM] and ≥2 white matter columns) are typical of PPMS. In patients with PPMS and those with relapse-onset MS, location of lesions in critical central nervous system regions (spinal cord, infratentorial regions, and GM) and MRI-detected high inflammatory activity in the first years after diagnosis are risk factors for long-term disability and future progressive disease course. These measures are evaluable in clinical practice. In patients with established MS, GM involvement and neurodegeneration are associated with accelerated clinical worsening. Subpial demyelination and slowly expanding lesions are novel indicators of progressive MS.

Conclusions and Relevance

Diagnosis of PPMS is more challenging than diagnosis of RRMS. No qualitative clinical, immunological, histopathological, or neuroimaging features differentiate PPMS and SPMS; both are characterized by imaging findings reflecting neurodegeneration and are also impacted by aging and comorbidities. Unmet diagnostic needs include identification of MRI markers capable of distinguishing PPMS from RRMS and predicting the evolution of RRMS to SPMS. Integration of multiple parameters will likely be essential to achieve these aims.

Siponimod: Disentangling disability and relapses in secondary progressive multiple sclerosis

Background:

In multiple sclerosis, impact of treatment on disability progression can be confounded if treatment also reduces relapses.

Objective:

To distinguish siponimod’s direct effects on disability progression from those on relapses in the EXPAND phase 3 trial.

Methods:

Three estimands, one based on principal stratum and two on hypothetical scenarios (no relapses, or equal relapses in both treatment arms), were defined to determine the extent to which siponimod’s effects on 3- and 6-month confirmed disability progression were independent of on-study relapses.

Results:

Principal stratum analysis estimated that siponimod reduced the risk of 3- and 6-month confirmed disability progression by 14%–20% and 29%–33%, respectively, compared with placebo in non-relapsing patients. In the hypothetical scenarios, risk reductions independent of relapses were 14%–18% and 23% for 3- and 6-month confirmed disability progression, respectively.

Conclusion:

By controlling the confounding impact of on-study relapses on confirmed disability progression, these statistical approaches provide a methodological framework to assess treatment effects on disability progression in relapsing and non-relapsing patients. The analyses support that siponimod may be useful for treating secondary progressive multiple sclerosis in patients with or without relapses.

Identifying Progression in Multiple Sclerosis: New Perspectives

The identification of progression in multiple sclerosis is typically retrospective. Given the profound burden of progressive multiple sclerosis, and the recent development of effective treatments for these patients, there is a need to establish measures capable of identifying progressive multiple sclerosis early in the disease course. Starting from recent pathological findings, this review assesses the state of the art of potential measures able to predict progressive multiple sclerosis. Future promising biomarkers that might shed light on mechanisms of progression are also discussed. Finally, expansion of the concept of progressive multiple sclerosis, by including an assessment of cognition, patient-reported outcomes, and comorbidities, is considered. ANN NEUROL 2020;88:438-452.

Imaging of the thoracic spinal cord using radially sampled averaged magnetization inversion recovery acquisitions

BACKGROUND

Spinal cord (SC) gray and white matter atrophy quantification by advanced morphometric MRI can help to better characterize the course of neurodegenerative diseases in vivo, such as e.g. lower motor neuron disorders. Imaging the lower thoracic cord - containing those motor neurons that control leg function - could be particularly informative, however, is challenging due to tissue composition, physiological motion and large field of views.

NEW METHOD

An "averaged magnetization inversion recovery acquisitions" (AMIRA) approach with a radial k-space acquisition scheme was developed. The method is designed for morphometric SC imaging with a focus on the thoracic SC.

RESULTS

In a typical setting, radial AMIRA acquires transverse slices with a high 0.50 × 0.50mm² in-plane resolution and a pronounced positive contrast between thoracic gray and white matter, within typically 2:39 min. Additional proof-of-concept measurements in patients demonstrate that such contrast and resolving capability is indeed necessary to assess potential atrophy of the anterior horns.

COMPARISON WITH EXISTING METHOD(S)

Radial AMIRA utilizes two benefits of radial MRI techniques: being generally less prone to motion effects and that fold over artifacts can manifest less intrusively. These benefits are united with the original AMIRA approach which allows the contrast to be 'tuned' and improved based on the combination of five simultaneously acquired images of different tissue contrast.

CONCLUSIONS

Radial AMIRA is a promising approach for in vivo SC gray and white matter atrophy visualization and quantification in lower motor neuron diseases and other autoimmune or genetic diseases involving the entire (not only cervical) spinal cord.

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.

Spinal Cord Involvement in MS and Other Demyelinating Diseases

Diagnostic accuracy is poor in demyelinating myelopathies, and therefore a challenge for neurologists in daily practice, mainly because of the multiple underlying pathophysiologic mechanisms involved in each subtype. A systematic diagnostic approach combining data from the clinical setting and presentation with magnetic resonance imaging (MRI) lesion patterns, cerebrospinal fluid (CSF) findings, and autoantibody markers can help to better distinguish between subtypes. In this review, we describe spinal cord involvement, and summarize clinical findings, MRI and diagnostic characteristics, as well as treatment options and prognostic implications in different demyelinating disorders including: multiple sclerosis (MS), neuromyelitis optica spectrum disorder, acute disseminated encephalomyelitis, anti-myelin oligodendrocyte glycoprotein antibody-associated disease, and glial fibrillary acidic protein IgG-associated disease. Thorough understanding of individual case etiology is crucial, not only to provide valuable prognostic information on whether the disorder is likely to relapse, but also to make therapeutic decision-making easier and reduce treatment failures which may lead to new relapses and long-term disability. Identifying patients with monophasic disease who may only require acute management, symptomatic treatment, and subsequent rehabilitation, rather than immunosuppression, is also important.

Force control during submaximal isometric contractions is associated with walking performance in persons with multiple sclerosis

Individuals with multiple sclerosis (MS) experience progressive declines in movement capabilities, especially walking performance. The purpose of our study was to compare the amount of variance in walking performance that could be explained by the functional capabilities of lower leg muscles in persons with MS and a sex- and age-matched control group. Participants performed two walking tests (6-min walk and 25-ft walk), strength tests for the plantar flexor and dorsiflexor muscles, and steady submaximal (10% and 20% maximum) isometric contractions. High-density electromyography (EMG) was recorded during the steady contractions, and the signals were decomposed to identify the discharge times of concurrently active motor units. There were significant differences between the two groups in the force fluctuations during the steady contractions (force steadiness), the strength of the plantar flexor and dorsiflexor muscles, and the discharge characteristics during the steady contractions. Performance on the two walking tests by the MS group was moderately associated with force steadiness of the plantar flexor and dorsiflexor muscles; worse force steadiness was associated with poorer walking performance. In contrast, the performance of the control group was associated with muscle strength (25-ft test) and force steadiness of the dorsiflexors and variance in common input of motor units to the plantar flexors (6-min test). These findings indicate that a reduction in the ability to maintain a steady force during submaximal isometric contractions is moderately associated with walking performance of persons with MS.NEW & NOTEWORTHY The variance in walking endurance and walking speed was associated with force control of the lower leg muscles during submaximal isometric contractions in individuals with multiple sclerosis (MS). In contrast, the fast walking speed of a sex- and age-matched control group was associated with the strength of lower leg muscles. These findings indicate that moderate declines in the walking performance of persons with MS are more associated with impairments in force control rather than decreases in muscle strength.

What role should spinal cord MRI take in the future of multiple sclerosis surveillance?

INTRODUCTION

In multiple sclerosis (MS), inflammatory, demyelinating, and neurodegenerative phenomena affect the spinal cord, with detrimental effects on patients' clinical disability. Although spinal cord imaging may be challenging, improvements in MRI technologies have contributed to better evaluate spinal cord involvement in MS.

AREAS COVERED

This review summarizes the current state-of-art of the application of conventional and advanced MRI techniques to evaluate spinal cord damage in MS. Typical features of spinal cord lesions, their role in the diagnostic work-up of suspected MS, their predictive role for subsequent disease course and clinical worsening, and their utility to define treatment response are discussed. The role of spinal cord atrophy and of other advanced MRI techniques to better evaluate the associations between spinal cord abnormalities and the accumulation of clinical disability are also evaluated. Finally, how spinal cord assessment could evolve in the future to improve monitoring of disease progression and treatment effects is examined.

EXPERT OPINION

Spinal cord MRI provides relevant additional information to brain MRI in understanding MS pathophysiology, in allowing an earlier and more accurate diagnosis of MS, and in identifying MS patients at higher risk to develop more severe disability. A future role in monitoring the effects of treatments is also foreseen.

Epidemiology and treatment of multiple sclerosis in elderly populations

The prevalence of multiple sclerosis (MS) and the age of affected patients are increasing owing to increased longevity of the general population and the availability of effective disease-modifying therapies. However, ageing presents unique challenges in patients with MS largely as a result of their increased frequency of age-related and MS-related comorbidities as well as transition of the disease course from an inflammatory to a neurodegenerative phenotype. Immunosenescence (the weakening of the immune system associated with natural ageing) might be at least partly responsible for this transition, which further complicates disease management. Currently approved therapies for MS are effective in preventing relapse but are not as effective in preventing the accumulation of disability associated with ageing and disease progression. Thus, ageing patients with MS represent a uniquely challenging population that is currently underserved by existing therapeutic regimens. This Review focuses on the epidemiology of MS in ageing patients. Unique considerations relevant to this population are discussed, including the immunology and pathobiology of the complex relationship between ageing and MS, the safety and efficacy of disease-modifying therapies, when discontinuation of treatment might be appropriate and the important role of approaches to support wellness and cognition.

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.

Intersubject Variability and Normalization Strategies for Spinal Cord Total Cross-Sectional and Gray Matter Areas

BACKGROUND AND PURPOSE

The quantification of spinal cord (SC) atrophy by MRI has assumed an important role in assessment of neuroinflammatory/neurodegenerative diseases and traumatic SC injury. Recent technical advances make possible the quantification of gray matter (GM) and white matter tissues in clinical settings. However, the goal of a reliable diagnostic, prognostic or predictive marker is still elusive, in part due to large intersubject variability of SC areas. Here, we investigated the sources of this variability and explored effective strategies to reduce it.

METHODS

One hundred twenty-nine healthy subjects (mean age: 41.0 ± 15.9) underwent MRI on a Siemens 3T Skyra scanner. Two-dimensional PSIR at the C2-C3 vertebral level and a sagittal 1 mm³ 3D T1-weighted brain acquisition extended to the upper cervical cord were acquired. Total cross-sectional area and GM area were measured at C2-C3, as well as measures of the vertebra, spinal canal and the skull. Correlations between the different metrics were explored using Pearson product-moment coefficients. The most promising metrics were used to normalize cord areas using multiple regression analyses.

RESULTS

The most effective normalization metrics were the V-scale (from SienaX) and the product of the C2-C3 spinal canal diameters. Normalization methods based on these metrics reduced the intersubject variability of cord areas of up to 17.74%. The measured cord areas had a statistically significant sex difference, while the effect of age was moderate.

CONCLUSIONS

The present work explored in a large cohort of healthy subjects the source of intersubject variability of SC areas and proposes effective normalization methods for its reduction.

Spinal cord involvement by atrophy and associations with disability are different between multiple sclerosis and neuromyelitis optica spectrum disorder

BACKGROUND AND PURPOSE

The cervical and thoracic cross-sectional spinal cord area (CS-SCA) in multiple sclerosis (MS) correlates with disability, whilst such a correlation remains to be established in neuromyelitis optica spectrum disorder (NMOSD). Our aim was to clarify differences between MS and NMOSD in spinal cord segments where CS-SCA is associated with disability.

METHODS

The CS-SCA at C2/C3, C3/C4, T8/T9 and T9/T10 vertebral disc levels was measured in 140 MS patients (111 with relapsing-remitting MS and 29 with progressive MS) and 42 NMOSD patients with anti-aquaporin-4 immunoglobulin G. Disability was evaluated by Expanded Disability Status Scale (EDSS) scores. Multivariate associations between CS-SCA and disability were assessed by stepwise forward multiple linear regression.

RESULTS

Thoracic CS-SCA was significantly smaller in NMOSD patients than in MS patients even after adjusting for age, sex and disease duration (P = 0.002 at T8/T9), whilst there was no difference in cervical CS-SCA between the two diseases. Cervical and thoracic CS-SCA had a negative correlation with EDSS scores in MS patients (P < 0.0001 at C3/C4 and P = 0.0002 at T8/T9) whereas only thoracic CS-SCA correlated with EDSS scores in NMOSD patients (P = 0.0006 at T8/T9). By multiple regression analyses, predictive factors for disability in MS were smaller cervical CS-SCA, progressive course, older age and a higher number of relapses, whilst those in NMOSD were smaller thoracic CS-SCA and older age.

CONCLUSIONS

Thoracic CS-SCA is a useful predictive marker for disability in patients with NMOSD whilst cervical CS-SCA is associated with disability in patients with MS.

Influence of CNS T2-focal lesions on cervical cord atrophy and disability in multiple sclerosis

Background:

Mechanisms associated with cervical spinal cord (CSC) and upper thoracic spinal cord (TSC) atrophy in multiple sclerosis (MS) are poorly understood.

Objective:

To assess the influence of brain, CSC and TSC T2-hyperintense lesions on cord atrophy and disability in MS.

Methods:

Thirty-four MS patients underwent 3T brain, cervical and thoracic cord magnetic resonance imaging (MRI) and Expanded Disability Status Scale (EDSS) score assessment. CSC/TSC lesion number and volume (LV), whole-brain and cortico-spinal tract (CST) LVs were obtained. Normalized whole CSC and upper TSC cross-sectional areas (CSAn) were also derived. Age- and sex-adjusted regression models assessed associations of brain/cord lesions with CSAn and EDSS and identified variables independently associated with CSAn and EDSS with a stepwise variable selection.

Results:

CSC CSAn (β = −0.36, p = 0.03) and TSC CSAn (β = −0.60, p < 0.001) were associated with CSC T2 LV. EDSS (median = 3.0) was correlated with CSC T2 LV (β = 0.42, p = 0.01), brain (β = 0.34, p = 0.04) and CST LV (β = 0.35, p = 0.03). The multivariate analysis retained CSC LV as significant predictor of CSC CSAn ( R2 = 0.20, p = 0.023) and TSC CSAn ( R2 = 0.51, p < 0.001) and retained CSC and CST LVs as significant predictors of EDSS ( R2 = 0.55, p = 0.001).

Conclusions:

CSC LV is an independent predictor of cord atrophy. When neurological impairment is relatively mild, central nervous system (CNS) lesion burden is a better correlate of disability than atrophy.

Multiple sclerosis neuropathic arthropathy of elbow: Report of a rare case and literature review

Neuropathic arthropathy (NA) is a progressive degenerative and destructive joint disease associated with underlying chronic neurologic deficit. A 34-year-old woman was referred to our tumor clinic with swelling and destruction of her left elbow joint. Except for a 5-year history of multiple sclerosis (MS), she had no other underlying diseases. Suspected of tumor involvement, she had been undergone an open biopsy. The pathologic report was fibromatosis, which was not compatible with imaging studies and clinical presentations. Second surgical inspection and cellular study didn’t prove tumoral involvement. Magnetic resonance images (MRIs) showed multiple hyper signal plaques in her cervical spine. MRI findings, clinical features, surgical observations, and disproportionate painless elbow destruction all confirmed the MS NA diagnosis.

Advances in spinal cord imaging in multiple sclerosis

The spinal cord is frequently affected in multiple sclerosis (MS), causing motor, sensory and autonomic dysfunction. A number of pathological abnormalities, including demyelination and neuroaxonal loss, occur in the MS spinal cord and are studied in vivo with magnetic resonance imaging (MRI). The aim of this review is to summarise and discuss recent advances in spinal cord MRI. Advances in conventional spinal cord MRI include improved identification of MS lesions, recommended spinal cord MRI protocols, enhanced recognition of MRI lesion characteristics that allow MS to be distinguished from other myelopathies, evidence for the role of spinal cord lesions in predicting prognosis and monitoring disease course, and novel post-processing methods to obtain lesion probability maps. The rate of spinal cord atrophy is greater than that of brain atrophy (-1.78% versus -0.5% per year), and reflects neuroaxonal loss in an eloquent site of the central nervous system, suggesting that it can become an important outcome measure in clinical trials, especially in progressive MS. Recent developments allow the calculation of spinal cord atrophy from brain volumetric scans and evaluation of its progression over time with registration-based techniques. Fully automated analysis methods, including segmentation of grey matter and intramedullary lesions, will facilitate the use of spinal cord atrophy in trial designs and observational studies. Advances in quantitative imaging techniques to evaluate neuroaxonal integrity, myelin content, metabolic changes, and functional connectivity, have provided new insights into the mechanisms of damage in MS. Future directions of research and the possible impact of 7T scanners on spinal cord imaging will be discussed.

The impact of cervical spinal cord atrophy on quality of life in multiple sclerosis

BACKGROUND

Spinal cord demyelination is common in multiple sclerosis (MS) and has been linked to increased disability and progressive clinical course. Spinal cord atrophy shows an especially close relationship to MS-related physical disability, though the relationship between spinal cord lesions/atrophy and health-related quality of life (QOL) has not been explored.

METHODS

62 patients (53 relapsing MS, 7 secondary progressive, 2 clinically isolated syndrome) from our center underwent 3 T MRI within 30 days of clinical examination and QOL assessment. Upper cervical (C1-C3) spinal cord area (UCCA) was obtained from 3D high-resolution MPRAGE sequences (1 mm isotropic voxels). Cervical spinal cord (C1-C7) lesion count, and cervical and brain T2 hyperintense lesion volumes were calculated. Brain parenchymal fraction (BPF) was obtained from an automated segmentation pipeline. Spearman correlations were assessed between MRI and clinical data. Partial Spearman correlations adjusting for age, disease duration, and BPF assessed the independent association between MRI variables and QOL domains.

RESULTS

UCCA showed an inverse relationship with age (r = -0.330, p = .009), disease duration, (r = -0.444, p < .001), and nine-hole peg test (r = -0.353, p = .005). The Upper Extremity Function QOL domain showed the strongest relationship to UCCA (r = 0.333, p = .008), with Lower Extremity Function QOL (r = 0.234, p = .067) and Satisfaction with Social Roles and Activities (r = 0.245, p = .055) correlations bordering significance. The association between UCCA and Upper Extremity QOL remained significant after adjustment for BPF, age, and disease duration. QOL domains reflective of psychological health (Depression, Anxiety, Emotional and Behavioral Dyscontrol, Positive Affect and Wellbeing) showed no relationship to UCCA. Cervical and brain lesion volume related to impairment in Stigma while cervical lesion count was unrelated to NeuroQOL impairment. Brain atrophy correlated with conventional markers of disability and cognition but did not have a significant relationship to QOL.

CONCLUSION

Cervical spinal cord volume is independently associated with impaired upper extremity-related QOL in patients with MS. These findings suggest specific clinical relevance of MS-related spinal cord atrophy as compared to brain or cervical spinal cord lesions, or whole brain atrophy.

Evaluation of Intra- and Interscanner Reliability of MRI Protocols for Spinal Cord Gray Matter and Total Cross-Sectional Area Measurements

BACKGROUND

In vivo quantification of spinal cord atrophy in neurological diseases using MRI has attracted increasing attention.

PURPOSE

To compare across different platforms the most promising imaging techniques to assess human spinal cord atrophy.

STUDY TYPE

Test/retest multiscanner study.

SUBJECTS

Twelve healthy volunteers.

FIELD STRENGTH/SEQUENCE

Three different 3T scanner platforms (Siemens, Philips, and GE) / optimized phase sensitive inversion recovery (PSIR), T1 -weighted (T1 -w), and T2 *-weighted (T2 *-w) protocols.

ASSESSMENT

On all images acquired, two operators assessed contrast-to-noise ratio (CNR) between gray matter (GM) and white matter (WM), and between WM and cerebrospinal fluid (CSF); one experienced operator measured total cross-sectional area (TCA) and GM area using JIM and the Spinal Cord Toolbox (SCT).

STATISTICAL TESTS

Coefficient of variation (COV); intraclass correlation coefficient (ICC); mixed effect models; analysis of variance (t-tests).

RESULTS

For all the scanners, GM/WM CNR was higher for PSIR than T2 *-w (P < 0.0001) and WM/CSF CNR for T1 -w was the highest (P < 0.0001). For TCA, using JIM, median COVs were smaller than 1.5% and ICC >0.95, while using SCT, median COVs were in the range 2.2-2.75% and ICC 0.79-0.95. For GM, despite some failures of the automatic segmentation, median COVs using SCT on T2 *-w were smaller than using JIM manual PSIR segmentations. In the mixed effect models, the subject was always the main contributor to the variance of area measurements and scanner often contributed to TCA variance (P < 0.05). Using JIM, TCA measurements on T2 *-w were different than on PSIR (P = 0.0021) and T1 -w (P = 0.0018), while using SCT, no notable differences were found between T1 -w and T2 *-w (P = 0.18). JIM and SCT-derived TCA were not different on T1 -w (P = 0.66), while they were different for T2 *-w (P < 0.0001). GM area derived using SCT/T2 *-w versus JIM/PSIR were different (P < 0.0001).

DATA CONCLUSION

The present work sets reference values for the magnitude of the contribution of different effects to cord area measurement intra- and interscanner variability.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2019;49:1078-1090.

Magnetic resonance imaging in immune-mediated myelopathies

Immune-mediated myelopathies are a heterogeneous group of inflammatory spinal cord disorders including autoimmune disorders with known antibodies, e.g. aquaporin-4 IgG channelopathy or anti-myelin oligodendrocyte glycoprotein-associated myelitis, myelopathies in the context of multiple sclerosis and systemic autoimmune disorders with myelopathy, as well as post-infectious and paraneoplastic myelopathies. Although magnetic resonance imaging of the spinal cord is still challenging due to the small dimension of the cord cross-section and frequent movement and susceptibility artifacts, recent methodological advances have led to improved diagnostic evaluation and characterization of immune-mediated myelopathies. Topography, length and width of the lesion, gadolinium enhancement pattern, and changes in morphology over time help in narrowing the broad differential diagnosis. In this review, we give an overview of recent advances in magnetic resonance imaging of immune-mediated myelopathies and its role in the differential diagnosis and monitoring of this heterogeneous group of disorders.

Gray vs. White Matter Segmentation of the Conus Medullaris: Reliability and Variability in Healthy Volunteers

BACKGROUND AND PURPOSE

Magnetic resonance imaging (MRI)-derived spinal cord (SC) gray and white matter (GM/WM) volume are useful indirect measures of atrophy and neurodegeneration over time, typically obtained in the upper SC. Neuropathological evidence suggests that in certain neurological conditions, early degeneration may occur as low as the sacral SC. In this study, the feasibility of GM/WM segmentation of the conus medullaris (CM) was assessed in vivo.

METHODS

Twenty-three healthy volunteers (11 female, mean age 47 years) underwent high-resolution 3T MRI of the CM using a 3-dimensional fast field echo sequence. Reproducibility of the volume measurements was assessed in 5 subjects (2 female, 25-37 years) by one rater who repeated the analysis 3 times and also with 2 additional raters working independently in order to calculate the intra- and interrater coefficient of variation (COV), respectively. Furthermore, the influence of age, gender, spine and SC metrics on tissue-specific measures of the CM was investigated.

RESULTS

Volumetric CM analyses (N = 23) for the SC, GM, and WM revealed a mean (SD) total volume of CM-TV = 1746.9 (296.7) mm³ , CM-GM-TV = 731.2 (106.0) mm³ , and CM-WM-TV = 1014.6 (211.3) mm³ , respectively. The intra-rater COV for measuring the CM-TV and CM-GM-TV was 3.38% and 7.42%, respectively; the interrater COV was 3.43% and 10.80%, respectively. Using age, gender, spine and SC metrics in regression models substantially reduced group variability for CM-TV, CM-WM-TV, and CM-GM-TV by up to 39.2%, 42.7%, and 21.2%, respectively.

CONCLUSIONS

The results from this study demonstrate the feasibility of obtaining tissue-specific volume measurements in the CM by means of MRI with good reproducibility and provide normative data for future applications in neurological diseases affecting the lower SC.

Correlations between cervical spinal cord magnetic resonance diffusion tensor and diffusion kurtosis imaging metrics and motor performance in patients with chronic ischemic brain lesions of the corticospinal tract

PURPOSE

To investigate modifications of Magnetic Resonance Diffusion Tensor Imaging (DTI) and Diffusion Kurtosis Imaging (DKI) metrics in lateral white matter (WM) bundles of the cervical spinal cord in patients with previous stroke in the vascular territory of the middle cerebral artery (MCA).

METHODS

Twenty consecutive patients with a previous ischemic stroke of the MCA territory and a varying degree of upper motor impairment were enrolled. DKI was centered at the C3C4 and C5C6 intervertebral level.

RESULTS

The fractional anisotropy (FA) values in C3C4 and C5C6 were found to be significantly lower in the lateral WM bundles contralateral to the ischemic lesion and thus, in the WM bundle including the affected corticospinal tract (CST) (p = 0.005 and p = 0.008, respectively), as well as mean kurtosis (MK) and axonal water fraction (AWF) values (p = 0.004 and p = 0.04. respectively). FA values correlated significantly with the Global Motor Index (GMI) both for C3C4 (ρ = 0.61, p = 0.004) and C5C6 (ρ = 0.69, p = 0.002). At C3C4, AWF correlated significantly with GMI (ρ = 0.54, p = 0.03). No correlations were found between lateral WM bundle volumes and GMI.

CONCLUSION

A reduction of anisotropy and microstructural complexity in the affected lateral WM bundle of the cervical spinal cord was observed in patients with previous ischemic stroke involving the CST. The correlations between these metrics and motor performance were statistically significant.

Monitoring Progressive Multiple Sclerosis with Novel Imaging Techniques

Imaging markers for monitoring disease progression in progressive multiple sclerosis (PMS) are scarce, thereby limiting the possibility to monitor disease evolution and to test effective treatments in clinical trials. Advanced imaging techniques that have the advantage of metrics with increased sensitivity to short-term tissue changes and increased specificity to the structural abnormalities characteristic of PMS have recently been applied in clinical trials of PMS. In this review, we (1) provide an overview of the pathological features of PMS, (2) summarize the findings of research and clinical trials conducted in PMS which have applied conventional and advanced magnetic resonance imaging techniques and (3) discuss recent advancements and future perspectives in monitoring PMS with imaging techniques.

Measurement of spinal cord atrophy using phase sensitive inversion recovery (PSIR) imaging in motor neuron disease

BACKGROUND

The spectrum of motor neuron disease (MND) includes numerous phenotypes with various life expectancies. The degree of upper and lower motor neuron involvement can impact prognosis. Phase sensitive inversion recovery (PSIR) imaging has been shown to detect in vivo gray matter (GM) and white matter (WM) atrophy in the spinal cord of other patient populations but has not been explored in MND.

METHODS

In this study, total cord, WM and GM areas of ten patients with a diagnosis within the MND spectrum were compared to those of ten healthy controls (HC). Patients' diagnosis included amyotrophic lateral sclerosis (ALS), primary lateral sclerosis, primary muscular atrophy, facial onset sensory and motor neuronopathy and ALS-Frontotemporal dementia. Axial 2D PSIR images were acquired at four cervical disc levels (C2-C3, C3-C4, C5-C6 and C7-T1) with a short acquisition time (2 minutes) protocol. Total cross-sectional areas (TCA), GM and WM areas were measured using a combination of highly reliable manual and semi-automated methods. Cord areas in MND patients were compared with HC using linear regression analyses adjusted for age and sex. Correlation of WM and GM areas in MND patients was explored to gain insights into underlying atrophy patterns.

RESULTS

MND patients as a group had significantly smaller cervical cord GM area compared to HC at all four levels (C2-C3: p = .009; C3-C4: p = .001; C5-C6: p = .006; C7-T1: p = .002). WM area at C5-C6 level was significantly smaller (p = .001). TCA was significantly smaller at C3-C4 (p = .018) and C5-C6 (p = .002). No significant GM and WM atrophy was detected in the two patients with predominantly bulbar phenotype. Concomitant GM and WM atrophy was detected in solely upper or lower motor neuron level phenotypes. There was a significant correlation between GM and WM areas at all four levels in this diverse population of MND.

CONCLUSION

Spinal cord GM and WM atrophy can be detected in vivo in patients within the MND spectrum using a short acquisition time 2D PSIR imaging protocol. PSIR imaging shows promise as a method for quantifying spinal cord involvement and thus may be useful for diagnosis, prognosis and for monitoring disease progression.

SUMMIT (Serially Unified Multicenter Multiple Sclerosis Investigation): creating a repository of deeply phenotyped contemporary multiple sclerosis cohorts

BACKGROUND

There is a pressing need for robust longitudinal cohort studies in the modern treatment era of multiple sclerosis.

OBJECTIVE

Build a multiple sclerosis (MS) cohort repository to capture the variability of disability accumulation, as well as provide the depth of characterization (clinical, radiologic, genetic, biospecimens) required to adequately model and ultimately predict a patient's course.

METHODS

Serially Unified Multicenter Multiple Sclerosis Investigation (SUMMIT) is an international multi-center, prospectively enrolled cohort with over a decade of comprehensive follow-up on more than 1000 patients from two large North American academic MS Centers (Brigham and Women's Hospital (Comprehensive Longitudinal Investigation of Multiple Sclerosis at the Brigham and Women's Hospital (CLIMB; BWH)) and University of California, San Francisco (Expression/genomics, Proteomics, Imaging, and Clinical (EPIC))). It is bringing online more than 2500 patients from additional international MS Centers (Basel (Universitätsspital Basel (UHB)), VU University Medical Center MS Center Amsterdam (MSCA), Multiple Sclerosis Center of Catalonia-Vall d'Hebron Hospital (Barcelona clinically isolated syndrome (CIS) cohort), and American University of Beirut Medical Center (AUBMC-Multiple Sclerosis Interdisciplinary Research (AMIR)).

RESULTS AND CONCLUSION

We provide evidence for harmonization of two of the initial cohorts in terms of the characterization of demographics, disease, and treatment-related variables; demonstrate several proof-of-principle analyses examining genetic and radiologic predictors of disease progression; and discuss the steps involved in expanding SUMMIT into a repository accessible to the broader scientific community.

Spinal Cord Atrophy in Multiple Sclerosis: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

Spinal cord atrophy (SCA) is an important emerging outcome measure in multiple sclerosis (MS); however, there is limited consensus on the magnitude and rate of atrophy. The objective of this study was to synthesize the available data on measures of SCA in MS.

METHODS

Using published guidelines, relevant literature databases were searched between 1977 and 2017 for case-control or cohort studies reporting a quantitative measure of SCA in MS patients. Random-effects models pooled cross-sectional measures and longitudinal rates of SCA in MS and healthy controls (HCs). Student's t-test assessed differences between pooled measures in patient subgroups. Heterogeneity was assessed using DerSimonian and Laird's Q-test and the I ² -index.

RESULTS

A total of 1,465 studies were retrieved including 94 that met inclusion and exclusion criteria. Pooled estimates of mean cervical spinal cord (SC) cross-sectional area (CSA) in all MS patients, relapsing-remitting MS (RRMS), all progressive MS, secondary progressive MS (SPMS), primary-progressive MS (PPMS), and HC were: 73.07 mm² (95% CI [71.52-74.62]), 78.88 mm² (95% CI [76.92-80.85]), 69.72 mm² (95% CI [67.96-71.48]), 68.55 mm² (95% CI [65.43-71.66]), 70.98 mm² (95% CI [68.78-73.19]), and 80.87 mm² (95% C I [78.70-83.04]), respectively. Pooled SC-CSA was greater in HC versus MS (P < .001) and RRMS versus progressive MS (P < .001). SCA showed moderate correlations with global disability in cross-sectional studies (r-value with disability score range [-.75 to -.22]). In longitudinal studies, the pooled annual rate of SCA was 1.78%/year (95%CI [1.28-2.27]).

CONCLUSIONS

The SC is atrophied in MS. The magnitude of SCA is greater in progressive versus relapsing forms and correlates with clinical disability. The pooled estimate of annual rate of SCA is greater than reported rates of brain atrophy in MS. These results demonstrate that SCA is highly relevant as an imaging outcome in MS clinical trials.

Involvement of Claudin-11 in Disruption of Blood-Brain, -Spinal Cord, and -Arachnoid Barriers in Multiple Sclerosis

It is important to understand the molecular mechanisms of barrier disruption in the central nervous system (CNS) of patients with multiple sclerosis (MS). The purpose of the present study was to clarify whether claudin-11 is involved in the disruption of two endothelial barriers (blood-brain barrier (BBB) and blood-spinal cord barrier (BSCB)) and two epithelial barriers (blood-arachnoid barrier (BAB) and blood-CSF barrier (BCSFB)) in the CNS in MS. Immunohistochemical analysis revealed that, in both normal human and mouse, claudin-11 is co-localized with claudin-5 in the brain and spinal cord capillaries. The absolute protein expression level of claudin-11 was nearly equal to that of claudin-5 in rat brain capillaries, but was 2.81-fold greater in human brain capillaries. The protein expressions of claudin-11 were significantly downregulated in the brain and spinal cord capillaries of an MS patient and experimental autoimmune encephalomyelitis (EAE) mice. Specific downregulation of claudin-11 with siRNA significantly increased the transfer of membrane-impermeable FITC-dextran across human brain capillary endothelial cell (hCMEC/D3) monolayer. As for the epithelial barrier, claudin-11 protein expression was not decreased in choroid plexus epithelial cells forming the BCSFB in EAE mice, whereas it was decreased in brain and spinal cord meninges that form the BAB. Specific downregulation of claudin-11 with siRNA in a rat choroid plexus epithelial cell (TR-CSFB) monolayer significantly increased the permeability of FITC-dextran. In conclusion, our present findings indicate that claudin-11 expression at the BBB, BSCB, and BAB, but not the BCSFB, is downregulated in multiple sclerosis, impairing the functional integrity of these barriers.