Thalamus volume and ambulation in multiple sclerosis: a cross-sectional study

Mapping brain volume change across time in primary-progressive multiple sclerosis

PURPOSE

Detection and prediction of the rate of brain volume loss with age is a significant unmet need in patients with primary progressive multiple sclerosis (PPMS). In this study we construct detailed brain volume maps for PPMS patients. These maps compare age-related changes in both cortical and sub-cortical regions with those in healthy individuals.

METHODS

We conducted retrospective analyses of brain volume using T1-weighted Magnetic Resonance Imaging (MRI) scans of a large cohort of PPMS patients and healthy subjects. The volume of brain parenchyma (BP), cortex, white matter (WM), deep gray matter, thalamus, and cerebellum were measured using the robust SynthSeg segmentation tool. Age- and gender-related regression curves were constructed based on data from healthy subjects, with the 95% prediction interval adopted as the normality threshold for each brain region.

RESULTS

We analyzed 495 MRI scans from 169 PPMS patients, aged 20-79 years, alongside 563 exams from healthy subjects aged 20-86. Compared to healthy subjects, a higher proportion of PPMS patients showed lower than expected brain volumes in all regions except the cerebellum. The most affected areas were BP, WM, and thalamus. Lower brain volumes correlated with longer disease duration for BP and WM, and higher disability for BP, WM, cortex, and thalamus.

CONCLUSIONS

Constructing age- and gender-related brain volume maps enabled identifying PPMS patients at a higher risk of brain volume loss. Monitoring these high-risk patients may lead to better treatment decisions and improve patient outcomes.

Volumetric and diffusion MRI abnormalities associated with dysarthria in multiple sclerosis

Up to half of all people with multiple sclerosis experience communication difficulties due to dysarthria, a disorder that impacts the motor aspects of speech production. Dysarthria in multiple sclerosis is linked to cerebellar dysfunction, disease severity and lesion load, but the neuroanatomical substrates of these symptoms remain unclear. In this study, 52 participants with multiple sclerosis and 14 age- and sex-matched healthy controls underwent structural and diffusion MRI, clinical assessment of disease severity and cerebellar dysfunction and a battery of motor speech tasks. Assessments of regional brain volume and white matter integrity, and their relationships with clinical and speech measures, were undertaken. White matter tracts of interest included the interhemispheric sensorimotor tract, cerebello-thalamo-cortical tract and arcuate fasciculus, based on their roles in motor and speech behaviours. Volumetric analyses were targeted to Broca's area, Wernicke's area, the corpus callosum, thalamus and cerebellum. Our results indicated that multiple sclerosis participants scored worse on all motor speech tasks. Fixel-based diffusion MRI analyses showed significant evidence of white matter tract atrophy in each tract of interest. Correlational analyses further indicated that higher speech naturalness-a perceptual measure of dysarthria-and lower reading rate were associated with axonal damage in the interhemispheric sensorimotor tract and left arcuate fasciculus in people with multiple sclerosis. Axonal damage in all tracts of interest also correlated with clinical scales sensitive to cerebellar dysfunction. Participants with multiple sclerosis had lower volumes of the thalamus and corpus callosum compared with controls, although no brain volumetrics correlated with measures of dysarthria. These findings indicate that axonal damage, particularly when measured using diffusion metrics, underpin dysarthria in multiple sclerosis.

Effects of power training in older patients with multiple sclerosis on neurodegeneration, neuromuscular function, and physical function. A study protocol for the "power training in older multiple sclerosis patients (PoTOMS) randomized control trial

Introduction

Approximately one-third of all persons with multiple sclerosis (pwMS) are older, i.e., having an age ≥60 years. Whilst ageing and MS separately elicit deteriorating effects on brain morphology, neuromuscular function, and physical function, the combination of ageing and MS may pose a particular challenge. To counteract such detrimental changes, power training (i.e., a type of resistance exercise focusing on moderate-to-high loading at maximal intended movement velocity) presents itself as a viable and highly effective solution. Power training is known to positively impact physical function, neuromuscular function, as well as brain morphology. Existing evidence is promising but limited to young and middle-aged pwMS, with the effects of power training remaining to be elucidated in older pwMS.

Methods

The presented 'Power Training in Older MS patients (PoTOMS)' trial is a national, multi-center, parallel-group, randomized controlled trial. The trial compares 24 weeks of usual care(n = 30) to 24 weeks of usual care and power training (n = 30). The primary outcome is whole brain atrophy rate. The secondary outcomes include changes in brain micro and macro structures, neuromuscular function, physical function, cognitive function, bone health, and patient-reported outcomes.

Ethics and dissemination

The presented study is approved by The Regional Ethics Committee (reference number 1-10-72-222-20) and registered at the Danish Data Protection Agency (reference number 2016-051-000001). All study findings will be published in scientific peer-reviewed journals and presented at relevant scientific conferences independent of the results. The www.clinicaltrials.gov identifier is NCT04762342.

Neuroimaging Technology in Exercise Neurorehabilitation Research in Persons with MS: A Scoping Review

There is increasing interest in the application of neuroimaging technology in exercise neurorehabilitation research among persons with multiple sclerosis (MS). The inclusion and focus on neuroimaging outcomes in MS exercise training research is critical for establishing a biological basis for improvements in functioning and elevating exercise within the neurologist's clinical armamentarium alongside disease modifying therapies as an approach for treating the disease and its consequences. Indeed, the inclusion of selective neuroimaging approaches and sensor-based technology among physical activity, mobility, and balance outcomes in such MS research might further allow for detecting specific links between the brain and real-world behavior. This paper provided a scoping review on the application of neuroimaging in exercise training research among persons with MS based on searches conducted in PubMed, Web of Science, and Scopus. We identified 60 studies on neuroimaging-technology-based (primarily MRI, which involved a variety of sequences and approaches) correlates of functions, based on multiple sensor-based measures, which are typically targets for exercise training trials in MS. We further identified 12 randomized controlled trials of exercise training effects on neuroimaging outcomes in MS. Overall, there was a large degree of heterogeneity whereby we could not identify definitive conclusions regarding a consistent neuroimaging biomarker of MS-related dysfunction or singular sensor-based measure, or consistent neural adaptation for exercise training in MS. Nevertheless, the present review provides a first step for better linking correlational and randomized controlled trial research for the development of high-quality exercise training studies on the brain in persons with MS, and this is timely given the substantial interest in exercise as a potential disease-modifying and/or neuroplasticity-inducing behavior in this population.

Non-Pharmacological Treatments of Cognitive Impairment in Multiple Sclerosis: A Review

Cognitive impairment (CI) represents a common symptom in patients suffering from multiple sclerosis (MS), which can affect every stage of the disease course. Recent studies seem to support cognitive rehabilitation (CR) for minimizing the CI consequences. We reviewed the currently available evidence on the non-pharmacological approaches to CI, with the aim of giving an overview of the treatments used worldwide, from the traditional methods to the most recent techniques. A search of the literature was conducted on PubMed (articles in English performed in the last five years on humans). A total of 37 articles met our eligibility criteria after screening titles, abstracts and full-text and were divided into three main groups: in-presence interventions; studies performed via tele-rehabilitation and miscellaneous. Despite the great heterogeneity of the intervention and assessment methods, the evidence suggests that a non-pharmacological approach can improve MS-related CI. Cognitive rehabilitation seems effective and well established, as well as the use of computerized CR having the benefit of being even more appealing. Limited conclusions can be drawn on group CR due to the small number of studies focused on this kind of intervention. Some of the innovative approaches (virtual reality, EEG-based neurofeedback, brain stimulation, exercise, diet modification) may play a role in future studies and should be deeply explored.

Serum NfL levels in the first five years predict 10-year thalamic fraction in patients with MS

Background

Serum neurofilament light chain (sNfL) levels are associated with relapses, MRI lesions, and brain volume in multiple sclerosis (MS).

Objective

To explore the value of early serum neurofilament light (sNfL) measures in prognosticating 10-year regional brain volumes in MS.

Methods

Patients with MS enrolled in the Comprehensive Longitudinal Investigations in MS at Brigham and Women's Hospital (CLIMB) study within five years of disease onset who had annual blood samples from years 1–10 (n = 91) were studied. sNfL was measured with a single molecule array (SIMOA) assay. We quantified global cortical thickness and normalized deep gray matter (DGM) volumes (fractions of the thalamus, caudate, putamen, and globus pallidus) from high-resolution 3 T MRI at 10 years. Correlations between yearly sNfL levels and 10-year MRI outcomes were assessed using linear regression models.

Results

sNfL levels from years 1 and 2 were associated with 10-year thalamus fraction. Early sNfL levels were not associated with 10-year putamen, globus pallidus or caudate fractions. At 10 years, cortical thickness was not associated with early sNfL levels, but was weakly correlated with total DGM fraction.

Conclusions

Early sNfL levels correlate with 10-year thalamic volume, supporting its role as a prognostic biomarker in MS.

Cognitive Function and Whole-Brain MRI Metrics Are Not Associated with Mobility in Older Adults with Multiple Sclerosis

Due to advances in disease-modifying medications and earlier management of comorbidities, adults with multiple sclerosis (MS) are living longer, and this coincides with the aging of the general population. One major problem among older adults with and without MS is limited mobility, a consequence of aging that often negatively affects quality of life. Identifying factors that contribute to mobility disability is needed to develop targeted rehabilitation approaches. This study examined cognitive processing speed and global brain atrophy as factors that may contribute to mobility disability in older adults with and without MS. Older adults (≥55 years) with MS (n = 31) and age- and sex-matched controls (n = 22) completed measures of mobility (Short Physical Performance Battery) and cognitive processing speed (Symbol Digit Modalities Test) and underwent an MRI to obtain whole-brain metrics (gray matter volume, white matter volume, ventricular volume) as markers of atrophy. Mobility was significantly worse in the MS group than in the control group (p = 0.004). Spearman correlations indicated that neither cognitive processing speed (MS: r_s = 0.26; Control: r_s = 0.08) nor markers of global brain atrophy (MS: r_s range = −0.30 to −0.06; Control: r_s range = −0.40 to 0.16) were significantly associated with mobility in either group. Other factors such as subcortical gray matter structures, functional connectivity, exercise/physical activity, and cardiovascular fitness should be examined as factors that may influence mobility in aging adults with and without MS.

A pilot randomized controlled trial of robotic exoskeleton-assisted exercise rehabilitation in multiple sclerosis

BACKGROUND

Co-occurring mobility and cognitive impairments are common, debilitating, and poorly-managed with pharmacological therapies in persons with multiple sclerosis (MS). Exercise rehabilitation (ER), particularly walking ER, has been suggested as one of the best approaches for managing these manifestations of MS. However, there is a focal lack of efficacy of ER on mobility and cognitive outcomes in persons with MS who present with substantial neurological disability. Such severe neurological disability oftentimes precludes the ability for participation in highly-intensive and repetitive ER that is necessary for eliciting adaptations in mobility and cognition. To address such a concern, robotic exoskeleton-assisted ER (REAER) might represent a promising intervention approach for managing co-occurring mobility and cognitive impairments in those with substantial MS disability who might not benefit from traditional ER.

METHODS

The current pilot single-blind, randomized controlled trial (RCT) compared the effects of 4-weeks of REAER with 4-weeks of conventional gait training (CGT) as a standard-of-care control condition on functional mobility (timed up-and-go; TUG), walking endurance (six-minute walk test; 6MWT), cognitive processing speed (CPS; Symbol Digit Modalities Test; SDMT), and brain connectivity (thalamocortical resting-state functional connectivity (RSFC) based on fMRI) outcomes in 10 persons with substantial MS-related neurological disability.

RESULTS

Overall, compared with CGT, 4-weeks of REAER was associated with large improvements in functional mobility (η_p²=.38), CPS (η_p²=.53), and RSFC between the thalamus and ventromedial prefrontal cortex (η_p²=.72), but not walking endurance (η_p²=.01). Further, changes in RSFC were moderately associated with changes in TUG, 6MWT, and SDMT performance, respectively, whereby increased thalamocortical RSFC was associated with improved functional mobility, walking endurance, and CPS (|ρ|>.36).

CONCLUSION

The current pilot RCT provides initial support for REAER as an approach for improving functional mobility and CPS, perhaps based on adaptive and integrative central nervous system plasticity, namely increases in RSFC between the thalamus and ventromedial prefrontal cortex, in a small sample of persons with substantial MS disability. Such a pilot trial provides proof-of-concept data for the design and implementation of an appropriately-powered RCT of REAER in a larger sample of persons with MS who present with co-occurring impairments in both mobility and cognitive functioning.

Combined exercise training improves cognitive functions in multiple sclerosis patients with cognitive impairment: A single-blinded randomized controlled trial

BACKGROUND

Cognitive impairment is common in patients with multiple sclerosis (MS). The effects of different exercise trainings on cognitive functions in patients with MS are promising. However, the effects are not yet clear in MS patients with cognitive impairment. This study aimed to investigate the effect of combined exercise training on different cognitive functions in MS patients with cognitive impairment.

METHODS

Relapsing-remitting and mild disabled MS patients with cognitive impairment were randomly assigned to two groups: Exercise Group (EG, n:17) and the Control Group (CG, n:17). The EG received a combined exercise training consisting of aerobic and Pilates training in three sessions per week for 8 weeks while the CG performed the relaxation exercises at home. Cognitive functions, walking capacity, fatigue, mood, and quality of life were assessed at baseline and after eight weeks using the Brief Repeatable Battery of Neuropsychological Tests (BRB-N), Six-Minute Walk Test (6-MWT), Fatigue Impact Scale (FIS), Beck's Depression Inventory (BDI) and MS Quality of Life-54 (MSQoL-54), respectively.

RESULTS

This study showed significant group-by-time interactions on long-term verbal memory, walking capacity, cognitive fatigue, and physical quality of life in favor of the EG (p<0.003). Moreover, verbal memory, visuospatial memory, verbal fluency, information processing speed, walking capacity, fatigue, and quality of life improved in the EG (p<0.05) while only verbal memory increased in the CG (p<0.05). Furthermore, the change in visuospatial memory was associated with the change in mental quality of life (r:0.352, p: 0.041) while the change in verbal fluency (r: -0.362, p:0.035) and processing speed (r: -0.356, p:0.039) were associated with the change in mood.

CONCLUSION

Combined exercise training has beneficial effects on different cognitive functions in mild disabled RRMS patients with cognitive impairment. In addition, there is a mutual relationship in improvements in cognitive functions, mood, and quality of life after exercise.

The Impact of Intracortical Lesions on Volumes of Subcortical Structures in Multiple Sclerosis

BACKGROUND AND PURPOSE

Recent studies showed thalamic atrophy in the early stages of MS. We investigated the impact of intracortical lesions on the volumes of subcortical structures (especially the thalamus) compared with other lesions in MS.

MATERIALS AND METHODS

Seventy-one patients with MS were included. The volumes of intracortical lesions and white matter lesions were identified on double inversion recovery and FLAIR, respectively, by using 3D Slicer. Volumes of white matter T1 hypointensities and subcortical gray matter, thalamus, caudate, putamen, and pallidum volumes were calculated using FreeSurfer. Age, MS duration, and the Expanded Disability Status Scale score were assessed.

RESULTS

Patients with intracortical lesions were older (P = .003), had longer disease duration (P < .001), and higher Expanded Disability Status Scale scores (P = .02). The presence of intracortical lesions was associated with a significant decrease of subcortical gray matter volume (P = .02). In our multiple regression model, intracortical lesion volume was the only predictor of thalamic volume (R ² = 0.4, b* = -0.28, P = .03) independent of white matter lesion volume and T1 hypointensity volume. White matter lesion volume showed an impact on subcortical gray matter volume in patients with relapsing-remitting MS (P = .04) and those with disease duration of <5 years (P = .04) and on thalamic volume in patients with Expanded Disability Status Scale scores of <4.0 (P = .01). By contrast, intracortical lesion volume showed an impact on subcortical gray matter and thalamic volumes in the secondary-progressive MS subgroup (P = .02 and P < .001) in patients with a long-standing disease course (P < .001 and P = .001) and more profound disability (P < .001 and P < .001).

CONCLUSIONS

Thalamic atrophy was explained better by intracortical lesions than by white matter lesion and T1 hypointensity volumes, especially in patients with more profound disability.

Relationship between MRI perfusion and clinical severity in multiple sclerosis

Perfusion alterations within several brain regions have been shown in multiple sclerosis patients using different magnetic resonance imaging (MRI) techniques. Furthermore, MRI-derived brain perfusion metrics have been investigated in association with multiple sclerosis phenotypes, physical disability, and cognitive impairment. However, a review focused on these aspects is still missing. Our aim was to review all the studies investigating the relationship between perfusion MRI and clinical severity during the last fifteen years to understand the clinical relevance of these findings. Perfusion differences among phenotypes were observed both with 1.5T and 3T scanners, with progressive multiple sclerosis presenting with lower perfusion values than relapsing-remitting multiple sclerosis patients. However, only 3T scanners showed a statistically significant distinction. Controversial results about the association between MRI-derived perfusion metrics and physical disability scores were found. However, the majority of the studies showed that lower brain perfusion and longer transit time are associated with more severe physical disability and worse cognitive performances.

Technology-enabled comprehensive characterization of multiple sclerosis in clinical practice

BACKGROUND

Objective and longitudinal measurements of disability in patients with multiple sclerosis (MS) are desired in order to monitor disease status and response to disease-modifying and symptomatic therapies. Technology-enabled comprehensive assessment of MS patients, including neuroperformance tests (NPTs), patient-reported outcome measures (PROMs), and MRI, is incorporated into clinical care at our center. The relationships of each NPT with PROMs and MRI measures in a real-world setting are incompletely studied, particularly in larger datasets.

OBJECTIVES

To demonstrate the utility of comprehensive neurological assessment and determine the association between NPTs, PROMs, and quantitative MRI measures in a large MS clinical cohort.

METHODS

NPTs (processing speed [PST], contrast sensitivity [CST], manual dexterity [MDT], and walking speed [WST]) and physical disability-related PROMs (Quality of Life in Neurological Disorders [Neuro-QoL], Patient Determined Disease Steps [PDDS], and Patient-Reported Outcomes Measurement Information System Global-10 [PROMIS-10] physical) were collected as part of routine clinical care. Fully-automated MRI analysis calculated T2-lesion volume (T2LV), whole brain fraction (WBF), thalamic volume (TV), and cervical spinal cord cross-sectional area (CA) for brain MRIs completed within 3 months of a clinic visit during which NPTs and PROMs were assessed. Spearman's rank correlation coefficients evaluated the cross-sectional associations of NPTs with PROMs and MRI measures. Linear regression was utilized to determine which combination of clinical characteristics, patient demographics, MRI measures, and PROMs best cross-sectionally explained each NPT result.

RESULTS

997 unique patients (age 47.7 ± 11.4 years, 71.8% female) who underwent assessments over a 2-year period were included. Correlations among NPTs and PROMs were moderate. PST correlations were strongest for Neuro-QoL upper extremity (NQ-UE) (Spearman's rho = 0.43) and lower extremity (NQ-LE) (0.47). CST correlations were strongest for NQ-UE (0.33), NQ-LE (0.36), and PDDS (-0.31). MDT correlations were strongest for NQ-UE (-0.53), NQ-LE (-0.54), and PDDS (0.53). WST correlations were strongest for PDDS (0.64) and NQ-LE (-0.65). NPTs also had moderate correlations with MRI metrics, the strongest of which were observed with PST (with T2LV (-0.44) and WBF (0.49)). Spearman's rho for other NPT-MRI correlations ranged from 0.23 to 0.36. Linear regression identified age, disease duration, PROMIS-10 physical, NQ-UE, NQ-LE, T2LV and WBF as significant cross-sectional explanatory variables for PST (adjusted R²=0.46). For CST, significant variables included age and NQ-LE (adjusted R² = 0.30). For MDT, significant variables included PDDS, PROMIS-10 physical, NQ-UE, NQ-LE, T2LV, and WBF (adjusted R²=0.37). For WST, significant variables included sex, PDDS, NQ-LE, T2LV, and CA (adjusted R²=0.39).

CONCLUSIONS

Impaired performance on NPTs correlated with worse physical disability-related PROMs and MRI disease severity, but the strongest cross-sectional explanatory variables for each NPT component varied. This study supports the use of comprehensive, objective quantification of MS status in clinical and research settings. Future longitudinal analyses can determine predictors of treatment response and disability worsening.

Quantitative Synthesis of Timed 25-Foot Walk Performance in Multiple Sclerosis

OBJECTIVE

To provide a meta-analysis of articles that have included the timed 25-foot walk (T25FW) in persons with multiple sclerosis (MS), quantify differences in T25FW scores between those with MS and controls without MS, and quantify differences between categories of disability status and clinical disease courses within MS.

DATA SOURCES

The literature search was conducted using 4 databases (Google Scholar, PubMed, Cumulative Index to Nursing and Allied Health, EBSCO Host). We searched reference lists of published articles to identify additional articles.

STUDY SELECTION

A systematic literature search identified articles reporting average T25FW performance in seconds between those with MS and controls without MS, between those with MS who had mild and moderate and/or severe disability status, and between relapsing-remitting and progressive clinical courses of MS.

DATA EXTRACTION

Information was extracted and categorized based on reported data: comparisons of controls without MS and MS, comparisons of mild and moderate and/or severe MS based on study-defined Expanded Disability Status Scale groups, and comparisons of relapsing-remitting and progressive MS clinical courses.

DATA SYNTHESIS

We performed a random effects meta-analysis to quantify differences between groups as estimated by effect sizes (ESs). We expressed the differences in Cohen d as well as the original units of the T25FW (ie, seconds).

CONCLUSIONS

There was a large difference in T25FW performance in MS compared with controls without MS (ES=-0.93, mean difference=2.4s, P<.01). Persons with moderate and/or severe disability walked substantially slower compared with mild disability (ES=-1.02, mean difference=5.4s, P<.01), and persons with progressive courses of MS walked substantially slower than relapsing-remitting MS (ES=-1.4, mean difference=13.4s, P<.01).

The Relevance of Neuroimaging Findings to Physical Disability in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system and one of the leading causes of disability in young adults. While some patients with MS have a benign course in which they develop limited disability even after many years, other patients have a rapidly progressive course resulting in severe disability. However, the progression of the disease, particularly disability, is currently a predictable course with neuroimaging features to some extend. Magnetic resonance imaging (MRI) is not only the main diagnostic tool but also used to monitor response to therapies, thanks to its high sensitivity and ability to identify clinically silent lesions. This report presents a literature review which examines in detail the relationship between MRI findings and disability.

Brain imaging of locomotion in neurological conditions

Impaired locomotion is a frequent and major source of disability in patients with neurological conditions. Different neuroimaging methods have been used to understand the brain substrates of locomotion in various neurological diseases (mainly in Parkinson's disease) during actual walking, and while resting (using mental imagery of gait, or brain-behavior correlation analyses). These studies, using structural (i.e., MRI) or functional (i.e., functional MRI or functional near infra-red spectroscopy) brain imaging, electrophysiology (i.e., EEG), non-invasive brain stimulation (i.e., transcranial magnetic stimulation, or transcranial direct current stimulation) or molecular imaging methods (i.e., PET, or SPECT) reveal extended brain networks involving both grey and white matters in key cortical (i.e., prefrontal cortex) and subcortical (basal ganglia and cerebellum) regions associated with locomotion. However, the specific roles of the various pathophysiological mechanisms encountered in each neurological condition on the phenotype of gait disorders still remains unclear. After reviewing the results of individual brain imaging techniques across the common neurological conditions, such as Parkinson's disease, dementia, stroke, or multiple sclerosis, we will discuss how the development of new imaging techniques and computational analyses that integrate multivariate correlations in "large enough datasets" might help to understand how individual pathophysiological mechanisms express clinically as an abnormal gait. Finally, we will explore how these new analytic methods could drive our rehabilitative strategies.

Integrative CNS Plasticity With Exercise in MS: The PRIMERS (PRocessing, Integration of Multisensory Exercise-Related Stimuli) Conceptual Framework

There is a proliferation of research examining the effects of exercise on mobility and cognition in the general population and those with neurological disorders as well as focal research examining possible neural mechanisms of such effects. However, there is seemingly a lack of focus on what it is about exercise, in particular, that drives adaptive central nervous system neuroplasticity. We propose a novel conceptual framework (ie, PRIMERS) that describes such adaptations as occurring via activity-dependent neuroplasticity based on the integrative processing of multisensory input and associated complex motor output that is required for the regulation of physiological systems during exercise behavior. This conceptual framework sets the stage for the systematic examination of the effects of exercise on brain connectivity, brain structure, and molecular/cellular mechanisms that explain improvements in mobility and cognition in the general population and persons with multiple sclerosis (MS). We argue that exercise can be viewed as an integrative, systems-wide stimulus for neurorehabilitation because impaired mobility and cognition are common and co-occurring in MS.

The consequence of cerebral small vessel disease: Linking brain atrophy to motor impairment in the elderly

In the elderly, brain structural deficits and gait disturbances due to cerebral small vessel disease (CSVD) have been well demonstrated. The relationships among CSVD, brain atrophy, and motor impairment, however, are far from conclusive. Particularly, the effect of CSVD on subcortical nuclear atrophy, motor performance of upper extremities, and associating patterns between brain atrophy and motor impairment remains largely unknown. To address these gaps, this study recruited 770 community-dwelling subjects (35-82 years of age), including both CSVD and non-CSVD individuals. For each subject, four motor tests involving upper and lower extremities were completed. High-resolution structural MRI was applied to extract gray matter (GM) volume, white matter volume, cortical thickness, surface area, and subcortical nuclear (caudate, putamen, pallidum, and thalamus) volumes. The results showed worse motor performance of lower extremities but relatively preserved performance of upper extremities in the CSVD group. Intriguingly, there was a significant association between the worse performance of upper extremities and atrophy of whole-brain GM and pallidum in the CSVD group but not in the non-CSVD group. In addition, mediation analysis confirmed a functional CSVD-to-"brain atrophy"-to-"motor impairment" pathway, that is, a mediating role of thalamic atrophy in the CSVD effect on walking speed in the elderly, indicating that CSVD impairs walking performance through damaging the integrity of the thalamus in aging populations. These findings provide important insight into the functional consequences of CSVD and highlight the importance of evaluating upper extremities functions and exploring their brain mechanisms in CSVD populations during aging.

Testosterone and estrogen in multiple sclerosis: from pathophysiology to therapeutics

INTRODUCTION

Neuroprotection and remyelination are two unmet needs in the treatment of multiple sclerosis (MS). Therapeutic potential has been identified with sexual hormones, supported in women by a decrease in MS activity during the pregnancy, in men by a greater severity of symptoms and a faster progression than in women. Areas covered: The therapeutic effect of testosterone and estrogens is reviewed. Both hormones have demonstrated an anti-inflammatory effect. Testosterone has an effect in protecting neurons in culture against glutamate-induced toxicity and oxidative stress, and stimulates myelin formation and regeneration mediated through the neural androgen receptor. In experimental autoimmune encephalomyelitis model, estrogens significantly decrease inflammation in the central nervous system via ERα, while its action on ERβ leads to myelin and axon reparation. Estriol therapy in two phase 2 trials showed a decrease in clinical disease activity and inflammatory parameters in MRI. However, evidence of a therapeutic effect of testosterone is scarce. Expert commentary: Phase 3 trials with estriol as an add-on supplementation are now mandatory. Testosterone is another candidate to be tested in phase 2 trials. These hormones should be considered as an adjunctive therapy. New validated tools are needed to assess their effect on neuroprotection and remyelination.

Effects of an individual 12-week community-located “start-to-run” program on physical capacity, walking, fatigue, cognitive function, brain volumes, and structures in persons with multiple sclerosis

Background:

Exercise therapy studies in persons with multiple sclerosis (pwMS) primarily focused on motor outcomes in mid disease stage, while cognitive function and neural correlates were only limitedly addressed.

Objectives:

This pragmatic randomized controlled study investigated the effects of a remotely supervised community-located “start-to-run” program on physical and cognitive function, fatigue, quality of life, brain volume, and connectivity.

Method:

In all, 42 pwMS were randomized to either experimental (EXP) or waiting list control (WLC) group. The EXP group received individualized training instructions during 12 weeks (3×/week), to be performed in their community aiming to participate in a running event. Measures were physical (VO2max, sit-to-stand test, Six-Minute Walk Test (6MWT), Multiple Sclerosis Walking Scale-12 (MSWS-12)) and cognitive function (Rao’s Brief Repeatable Battery (BRB), Paced Auditory Serial Attention Test (PASAT)), fatigue (Fatigue Scale for Motor and Cognitive Function (FSMC)), quality of life (Multiple Sclerosis Impact Scale-29 (MSIS-29)), and imaging. Brain volumes and diffusion tensor imaging (DTI) were quantified using FSL-SIENA/FIRST and FSL-TBSS.

Results:

In all, 35 pwMS completed the trial. Interaction effects in favor of the EXP group were found for VO2max, sit-to-stand test, MSWS-12, Spatial Recall Test, FSMC, MSIS-29, and pallidum volume. VO2max improved by 1.5 mL/kg/min, MSWS-12 by 4, FSMC by 11, and MSIS-29 by 14 points. The Spatial Recall Test improved by more than 10%.

Conclusion:

Community-located run training improved aerobic capacity, functional mobility, visuospatial memory, fatigue, and quality of life and pallidum volume in pwMS.

The Role of T1-Weighted Derived Measures of Neurodegeneration for Assessing Disability Progression in Multiple Sclerosis

Introduction

Multiple sclerosis (MS) is characterised by the accumulation of permanent neurological disability secondary to irreversible tissue loss (neurodegeneration) in the brain and spinal cord. MRI measures derived from T1-weighted image analysis (i.e., black holes and atrophy) are correlated with pathological measures of irreversible tissue loss. Quantifying the degree of neurodegeneration in vivo using MRI may offer a surrogate marker with which to predict disability progression and the effect of treatment. This review evaluates the literature examining the association between MRI measures of neurodegeneration derived from T1-weighted images and disability in MS patients.

Methods

A systematic PubMed search was conducted in January 2017 to identify MRI studies in MS patients investigating the relationship between “black holes” and/or atrophy in the brain and spinal cord, and disability. Results were limited to human studies published in English in the previous 10 years.

Results

A large number of studies have evaluated the association between the previous MRI measures and disability. These vary considerably in terms of study design, duration of follow-up, size, and phenotype of the patient population. Most, although not all, have shown that there is a significant correlation between disability and black holes in the brain, as well as atrophy of the whole brain and grey matter. The results for brain white matter atrophy are less consistently positive, whereas studies evaluating spinal cord atrophy consistently showed a significant correlation with disability. Newer ways of measuring atrophy, thanks to the development of segmentation and voxel-wise methods, have allowed us to assess the involvement of strategic regions of the CNS (e.g., thalamus) and to map the regional distribution of damage. This has resulted in better correlations between MRI measures and disability and in the identification of the critical role played by some CNS structures for MS clinical manifestations.

Conclusion

The evaluation of MRI measures of atrophy as predictive markers of disability in MS is a highly active area of research. At present, measurement of atrophy remains within the realm of clinical studies, but its utility in clinical practice has been recognized and barriers to its implementation are starting to be addressed.

Objectively measured sedentary behavior and brain volumetric measurements in multiple sclerosis

Aim: This study examined the association between sedentary behavior patterns and whole brain gray matter (GM), white matter (WM) and subcortical GM structures in persons with multiple sclerosis (MS). Methods: 36 persons with MS wore an accelerometer and underwent a brain MRI. Whole brain GM and WM and deep GM structures were calculated from 3D T1-weighted structural brain images. Results: There were statistically significant (p < 0.01) and moderate or large associations between number of sedentary bouts/day and brain volume measures. The primary result was a consistent negative association between number of sedentary bouts/day and whole brain GM and WM, and deep GM structures. Conclusion: We provide novel evidence for decreased brain volume as a correlate of a sedentary behavior pattern in persons with MS.

Imaging as an Outcome Measure in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system. Magnetic resonance imaging (MRI) is sensitive to lesion formation both in the brain and spinal cord. Imaging plays a prominent role in the diagnosis and monitoring of MS. Over a dozen anti-inflammatory therapies are approved for MS and the development of many of these medications was made possible through the use of contrast-enhancing lesions on MRI as a phase II outcome. A similar phase II outcome method for the neurodegeneration that underlies progressive courses of the disease is still unavailable. Although magnetic resonance is an invaluable tool for the diagnosis and monitoring of treatment effects in MS, several imaging barriers still exist. In general, MRI is less sensitive to gray matter lesions, lacks pathological specificity, and does not provide quantitative data easily. Several advanced imaging methods including diffusion tensor imaging, magnetization transfer, functional MRI, myelin water fraction imaging, ultra-high field MRI, positron emission tomography, and optical coherence tomography of the retina study promising ways of overcoming the difficulties in MS imaging.