Physical exercise and synaptic protection in human and pre-clinical models of multiple sclerosis

In multiple sclerosis, only immunomodulatory and immunosuppressive drugs are recognized as disease-modifying therapies. However, in recent years, several data from pre-clinical and clinical studies suggested a possible role of physical exercise as disease-modifying therapy in multiple sclerosis. Current evidence is sparse and often conflicting, and the mechanisms underlying the neuroprotective and antinflammatory role of exercise in multiple sclerosis have not been fully elucidated. Data, mainly derived from pre-clinical studies, suggest that exercise could enhance long-term potentiation and thus neuroplasticity, could reduce neuroinflammation and synaptopathy, and dampen astrogliosis and microgliosis. In humans, most trials focused on direct clinical and MRI outcomes, as investigating synaptic, neuroinflammatory, and pathological changes is not straightforward compared to animal models. The present review analyzed current evidence and limitations in research concerning the potential disease-modifying therapy effects of exercise in multiple sclerosis in animal models and human studies.

Focusing on neural mechanisms of exercise training benefits in multiple sclerosis

Exercise training (ET) should be a mainstay of comprehensive care in multiple sclerosis (MS), yet there is reluctance regarding its implementation among healthcare providers. This reluctance has its roots in the lack of evidence from randomized controlled trials (RCTs) that provide a neurobiological mechanism for beneficial outcomes. We argue that ET training is efficacious for improving mobility and cognitive dysfunction as hallmark consequences of MS, and propose an experimental medicine framework for guiding research focusing on CNS mechanisms-of-action for ET benefits. The framework establishes three hierarchical pathways as preconditions for applying a mediation framework in a fourth pathway for fully testing mechanistic research questions using a RCT. This paper describes the conceptual basis of the pathways, and then reviews the existing evidence within the pathways of the framework for ET effects on the CNS, mobility, and cognition in MS. Lastly, this paper discusses future directions and challenges for testing the pathways of the framework for advancing the evidence regarding CNS mechanisms of ET benefits in this population. Our objective is guiding the field toward evidence that facilitates the prescription and promotion of ET as a neurorestorative approach within MS clinical practice.

Free-living ambulatory physical activity and cognitive function in multiple sclerosis: the significance of step rate vs. step volume

BACKGROUND

Physical activity (PA) represents a promising behavioral approach for managing cognitive dysfunction in multiple sclerosis (MS). However, there is a lack of information on the pattern of free-living PA intensity (e.g., step rate) and its unique association with cognition. Such information is essential for informing clinical trials in MS.

OBJECTIVE

We examined associations among PA volume and intensity with cognitive function in persons with MS, and intensity was derived from steps-based metrics (peak 30-min cadence [Peak-30CAD], and time spent in incremental cadence bands).

METHODS

We included data from 147 persons with MS who underwent assessments of cognitive function (via Brief International Cognitive Assessment in MS) and wore an ActiGraph GT3X + accelerometer for 7 days. We performed bivariate and partial correlations and regression analyses examining associations among PA metrics and cognitive outcomes.

RESULTS

Higher Peak-30CAD was significantly associated with better performance in cognitive processing speed and verbal learning and memory (rs = 0.19-0.38), and the associations remained significant when controlling for daily steps, age, sex, and years of education (p < 0.05). By comparison, daily steps was only correlated with cognitive processing speed (rs = 0.26), and the association was non-significant when controlling for Peak-30CAD and covariates. There were stronger correlations among time spent in higher intensity cadence bands with cognitive performance (rs = 0.18-0.38).

CONCLUSION

Our results highlight the important role of PA intensity for cognition in MS, and may inform future development of focal PA interventions that focusing on step rate patterns for improving cognition in persons with MS.

Internet-delivered lifestyle physical activity intervention for cognitive processing speed in multiple sclerosis

BACKGROUND

We propose a randomized controlled trial(RCT) of a Social Cognitive Theory-based(SCT), Internet-delivered behavioral intervention targeting lifestyle physical activity(LPA) for yielding improvements in cognitive processing speed(CPS), learning and memory(L/M), symptoms, and quality of life(QOL) among persons with mild multiple sclerosis(MS)-related ambulatory impairment who have impaired CPS.

METHODS/DESIGN

The study involves a Phase-II, parallel group, RCT design. Participants with MS(N = 300) will be randomly assigned on an equal basis(1:1) into behavioral intervention(n = 150) or attention and social contact control(n = 150) conditions. The conditions will be administered over 6-months by trained behavior coaches who will be uninvolved in screening, recruitment, random assignment, and outcome assessment. We will collect outcome data remotely every 6-months over the 12-month period(baseline, immediate follow-up, and 6-month follow-up) using a treatment blinded assessor. The primary outcome is the raw, oral Symbol Digit Modalities Test as a neuropsychological measure of CPS. The secondary outcomes include the California Verbal Learning Test-II as an objective measure of L/M, and patient-reported outcomes of fatigue, depressive symptoms, anxiety, pain, and QOL. The tertiary outcome is accelerometry as an objective, device-based measure of steps/day for generating a minimal clinically important difference(MCID) value that guides the prescription of LPA for improving CPS in clinical practice. The primary data analyses will involve intent-to-treat principles, and mixed-effects models and logistic regression.

DISCUSSION

If successful, the proposed study will provide Class I evidence for the efficacy of a theory-based, Internet-delivered behavioral intervention focusing on LPA for improving CPS and mitigating its negative impact on other outcomes in persons with MS.

CLINICALTRIALS

gov: NCT04518657.

Multimodal agility-based exercise training (MAT) versus strength and endurance training (SET) to improve multiple sclerosis-related fatigue and fatigability during inpatient rehabilitation: a randomized controlled pilot and feasibility study [ReFEx]

BACKGROUND

Multimodal agility-based exercise training (MAT) is a group-based exercise training framework for persons with multiple sclerosis (pwMS) with a potential to impact fatigue and fatigability. In a mixed-methods design, this study evaluated the feasibility of implementing MAT in an inpatient rehabilitation setting and the feasibility of a randomized controlled trial (RCT) study protocol with 'traditional' strength and endurance training (SET) as an active control condition. Secondarily, preliminary outcome data was acquired.

METHODS

PwMS with low to moderate disability and self-reported fatigue were randomly allocated to either MAT or SET when starting inpatient rehabilitation (4-6 weeks). The MAT-participants exercised in a group following a MAT-manual (sessions were gym- (5x/week) and pool-based (3x/week)). SET-participants exercised individually 5x/week on a cycle ergometer, and 3x/week on strength training machines. Feasibility assessments focused on processes, resources, management, time, and scientific domains. Assessed clinical outcomes at admission and discharge included perceived fatigue, motor and cognitive fatigability, cognitive performance, motor function, and balance confidence. Perceived fatigue was reassessed 1, 4, and 12 weeks after discharge. Feasibility was determined regarding predetermined progression criteria.

RESULTS

Twenty-two participants were randomized. Both groups performed the minimum number of sessions (> 18), and retention was adequate (73-91%). SET-participants performed more sessions than MAT-participants (30.8 vs. 22.7) and stayed longer in the facility (34.2 vs. 31.6 days). Non-eligibility of admitted pwMS was high (74% non-eligible), mainly due to high EDSS and inability to attend pool-based sessions. Consequently, recruitment (1.8/month) was slower than the predetermined progression criterium. Baseline assessments took longer than required (only 50% completed within 3 days). Short-term fatigue reduction was similar for both groups. Motor fatigability also improved in both groups, whereas cognitive fatigability deteriorated. In MAT, average improvement in walking endurance (43.9 m) exceeded minimal important change values for individuals (> 26.9 m).

CONCLUSIONS

Progressing to a definitive RCT necessitates adaptation of eligibility criteria. In the present design it will also be difficult to attain similar dosing of interventions. A multicenter RCT focused only on gym-based MAT might be another option to assess the effect of MAT. The primary outcome measure should be able to measure change in perceived fatigue more robustly.

TRIAL REGISTRATION

German Clinical Trials Register: DRKS00023943, date of registration: 23 September 2021.

Impact of physical activity, physical fitness and exercises on cognitive impairment in patients with multiple sclerosis: A review of evidence and underlying mechanisms

Cognitive impairment in persons with MS (pwMS) occurs commonly, early and independently of other clinical features of the disease. MS-related cognitive impairment is mainly characterized by weakening of information processing speed, working memory and episodic memory. Much evidence, based on both neuropsychological and neuroimaging outcomes, highlights successful cognitive rehabilitation interventions. In this context, promotion of physical activity and exercise training could be a dual, motor and cognitive, rehabilitation method. The aim of this article is, firstly, to review existing evidence regarding the effects of exercise on cognition among pwMS, and secondly, to explore the possible mechanisms of action of the cognitive-motor coupling.

Physical fitness moderates the association between brain network impairment and both motor function and cognition in progressive multiple sclerosis

BACKGROUND

Neurodegeneration leads to continuous accumulation of disability in progressive Multiple Sclerosis (MS). Exercise is considered to counteract disease progression, but little is known on the interaction between fitness, brain networks and disability in MS.

OBJECTIVE

The aim of this study to explore functional and structural brain connectivity and the interaction between fitness and disability based on motor and cognitive functional outcomes in a secondary analysis of a randomised, 3-month, waiting group controlled arm ergometry intervention in progressive MS.

METHODS

We modelled individual structural and functional brain networks based on magnetic resonance imaging (MRI). We used linear mixed effect models to compare changes in brain networks between the groups and explore the association between fitness, brain connectivity and functional outcomes in the entire cohort.

RESULTS

We recruited 34 persons with advanced progressive MS (pwMS, mean age 53 years, females 71%, mean disease duration 17 years and an average walking restriction of < 100 m without aid). Functional connectivity increased in highly connected brain regions of the exercise group (p = 0.017), but no structural changes (p = 0.817) were observed. Motor and cognitive task performance correlated positively with nodal structural connectivity but not nodal functional connectivity. We also found that the correlation between fitness and functional outcomes was stronger with lower connectivity.

CONCLUSIONS

Functional reorganisation seems to be an early indicator of exercise effects on brain networks. Fitness moderates the relationship between network disruption and both motor and cognitive outcomes, with growing importance in more disrupted brain networks. These findings underline the need and opportunities associated with exercise in advanced MS.

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.

Feasibility of remotely delivered and supported aerobic walking exercise training for cognitive processing speed impairment in fully-ambulatory persons with multiple sclerosis

PURPOSE

The current pilot, single-blind, randomized controlled trial (RCT) examined the feasibility of remotely-delivered and supported aerobic walking exercise training compared with an active control condition on cognitive processing speed (CPS) in 19 fully-ambulatory persons with multiple sclerosis (pwMS) who were pre-screened for impaired CPS.

METHODS

Feasibility was assessed in the domains of process (e.g., recruitment), resource (e.g., monetary costs), management (e.g., time requirements), and scientific outcomes (i.e., treatment effect). Fully-ambulatory, but CPS-impaired pwMS were randomly assigned into either 16-weeks of home-based aerobic walking exercise or home-based stretching and range-of-motion activities. Both conditions involved delivery of informational newsletters and one-on-one, online video chats with a behavior coach. Participants across both conditions tracked their activity using highly accurate wearable motion sensors. Treatment-blinded assessors administered the Symbol Digit Modalities Test (SDMT) remotely before and after the 16-week study period.

RESULTS

The study was cost-effective, accessible, and acceptable. The intervention further was safe. Adherence and compliance rates across both conditions exceeded 80%. There was an overall moderate effect for change in SDMT score between the conditions (d = 0.42). The intervention was associated with a 4.8-point improvement in SDMT scores (d = 0.70; 10% increase) compared with a 1-point improvement for the control condition (d = 0.09; 2% increase).

CONCLUSIONS

This remotely-delivered and supported aerobic walking exercise training intervention was safe and feasible for fully-ambulatory, CPS-impaired pwMS. The pattern of results, including the promising effects on CPS, support the design and implementation of an appropriately-powered RCT on this approach for managing CPS impairment in a large MS sample.

Training reactive balance using trips and slips in people with multiple sclerosis: a blinded randomised controlled trial

BACKGROUND

This study examined the feasibility and efficacy of reactive balance training for improving stepping performance and reducing laboratory-induced falls in people with multiple sclerosis (MS).

METHODS

Thirty people diagnosed with MS (18-70 years) participated in a blinded randomized controlled trial (ACTRN12618001436268). The intervention group (n = 14) underwent two 50-minute sessions (total 100 min) that exposed them to a total of 24 trips and 24 slips in mixed order, over one week. The control group (n = 16) received sham training (stepping over foam obstacles) with equivalent dosage. The primary outcome was falls into the harness (defined as >30% body weight) when exposed to trips and slips that were unpredictable in timing, location and type at post-assessment. Physical and psychological measures were also assessed at baseline and post assessments.

RESULTS

The intervention and control groups completed 86% and 95% of the training protocols respectively. Incidence rate ratios (95% confidence intervals) of the intervention group relative to the control group were 0.57 (0.25, 1.26) for all falls, 0.80 (0.30, 2.11) for slip falls and 0.20 (0.04, 0.96) for trip falls in the laboratory. Kinematic analyses indicated the intervention participants improved dynamic stability, with higher centre of mass position and reduced trunk sway during recovery steps following a trip, compared to control. There were no significant differences between the intervention and control participants at post-assessment for other secondary outcome measures.

CONCLUSIONS

Reactive balance training improved trip-induced dynamic stability, limb support, trunk control and reduced falls in people with MS. More research is required to optimise the training protocol and determine whether the beneficial effects of reactive balance training can be retained long term and generalize to fewer daily-life falls.

Multimodal Agility-Based Exercise Training for Persons With Multiple Sclerosis: A New Framework

INTRODUCTION

Multimodal agility-based exercise training (MAT) has been described as a framework for fall prevention in the elderly but might also be a valuable concept for exercise training in persons with Multiple Sclerosis (pwMS).

THE PROBLEM

Current recommendations advise pwMS to perform a multitude of different exercise training activities, as each of these has its separate evidence. However, pwMS struggle even more than the general population to be physically active. Additionally, Multiple Sclerosis often leads to co-occurring mobility and cognitive dysfunctions, for which simultaneous, time-efficient, and engaging training approaches are still limited in clinical practice and healthcare.

THE SOLUTION

The MAT framework has been developed to integratively improve cardiovascular, neuromuscular, and cognitive function by combining aspects of perception and orientation, change of direction, as well as stop-and-go patterns (ie, agility), in a group-training format. For pwMS, the MAT framework is conceptualized to include 3 Components: standing balance, dynamic balance (including functional leg strength), and agility-based exercises. Within these Components sensory, cognitive, and cardiovascular challenges can be adapted to individual needs.

RECOMMENDATIONS

We recommend investigating multimodal exercise interventions that go beyond easily standardized, unimodal types of exercise (eg, aerobic or resistance exercise), which could allow for time-efficient training, targeting multiple frequent symptoms of persons with mild disability at once. MAT should be compared to unimodal approaches, regarding sensor-based gait outcomes, fatigue-related outcomes, cognition, as well as neuroprotective, and (supportive) disease-modifying effects.

Neurorehabilitation in Multiple Sclerosis-A Review of Present Approaches and Future Considerations

Multiple sclerosis is an increasingly prevalent disease, representing the leading cause of non-traumatic neurological disease in Europe and North America. The most common symptoms include gait deficits, balance and coordination impairments, fatigue, spasticity, dysphagia and an overactive bladder. Neurorehabilitation therapeutic approaches aim to alleviate symptoms and improve the quality of life through promoting positive immunological transformations and neuroplasticity. The purpose of this study is to evaluate the current treatments for the most debilitating symptoms in multiple sclerosis, identify areas for future improvement, and provide a reference guide for practitioners in the field. It analyzes the most cited procedures currently in use for the management of a number of symptoms affecting the majority of patients with multiple sclerosis, from different training routines to cognitive rehabilitation and therapies using physical agents, such as electrostimulation, hydrotherapy, cryotherapy and electromagnetic fields. Furthermore, it investigates the quality of evidence for the aforementioned therapies and the different tests applied in practice to assess their utility. Lastly, the study looks at potential future candidates for the treatment and evaluation of patients with multiple sclerosis and the supposed benefits they could bring in clinical settings.

Integrated Cognitive Rehabilitation Home-Based Protocol to Improve Cognitive Functions in Multiple Sclerosis Patients: A Randomized Controlled Study

Cognitive impairment (CI) occurs in about 40-65% of people with multiple sclerosis (MS) during the disease course. Cognitive rehabilitation has produced non-univocal results in MS patients.

OBJECTIVE

The present study aimed to evaluate whether an Integrated Cognitive Rehabilitation Program (ICRP) in MS patients might significantly improve CI.

METHODS

Forty patients with three phenotypes of MS were randomly assigned into two groups: the experimental group (EG, n = 20), which participated in the ICRP for 10 weeks of training; and the control group (CG, n = 20). All participants' cognitive functions were assessed at three timepoints (baseline, post-treatment, and 3-month follow-up) with the California Verbal Learning (CVLT), Brief Visuospatial Memory (BVMTR), Numerical Stroop, and Wisconsin tests.

RESULTS

When compared to CG patients, EG patients showed significant improvements in several measures of cognitive performance after ICRP, including verbal learning, visuospatial memory, attention, and executive functions.

CONCLUSIONS

Home-based ICRP can improve cognitive functions and prevent the deterioration of patients' cognitive deficits. As an integrated cognitive rehabilitation program aimed at potentiation of restorative and compensatory mechanisms, this approach might suggest an effective role in preserving neuronal flexibility as well as limiting the progression of cognitive dysfunction in MS.

Developing the Rationale for Including Virtual Reality in Cognitive Rehabilitation and Exercise Training Approaches for Managing Cognitive Dysfunction in MS

Cognitive impairment is a common and detrimental consequence of multiple sclerosis (MS) and current rehabilitation methods are insufficient. Cognitive rehabilitation (CR) and exercise training (ET) are the most promising behavioral approaches to mitigate cognitive deficits, but effects are small and do not effectively translate to improvements in everyday function. This article presents a conceptual framework supporting the use of virtual reality (VR) as an ideal, common adjuvant traditional CR and ET in MS. VR could strengthen the effects of CR and ET by increasing sensory input and promoting multisensory integration and processing during rehabilitation. For ET specifically, VR can also help incorporate components of CR into exercise sessions. In addition, VR can enhance the transfer of cognitive improvements to everyday functioning by providing a more ecologically valid training environment. There is a clear interest in adding VR to traditional rehabilitation techniques for neurological populations, a stronger body of evidence of this unique approach is needed in MS. Finally, to better understand how to best utilize VR in rehabilitation for cognitive deficits in MS, more systematic research is needed to better understand the mechanism(s) of action of VR with CR and ET.

Cardiorespiratory fitness and free-living physical activity are not associated with cognition in persons with progressive multiple sclerosis: Baseline analyses from the CogEx study

BACKGROUND

Aerobic exercise training (physical activity for improving cardiorespiratory fitness) represents a promising approach for managing cognitive impairment in multiple sclerosis (MS). However, there is limited evidence that levels of physical activity and fitness are associated with cognition in progressive MS.

OBJECTIVE

We examined associations among cardiorespiratory fitness, moderate-to-vigorous physical activity (MVPA), and cognitive performance in a large, international progressive MS sample.

METHODS

Two hundred forty European and North American persons with progressive MS underwent cardiorespiratory fitness measurement on a recumbent stepper, wore an ActiGraph GT3X + accelerometer for 7 days for measuring MVPA, and underwent the Brief International Cognitive Assessment in MS.

RESULTS

Cardiorespiratory fitness was not significantly correlated with Symbol Digit Modalities Test (SDMT; r = -0.01; r = -0.04), California Verbal Learning Test-II (CVLT-II; r = 0.05; r = 0.05), or Brief Visuospatial Memory Test-Revised (BVMT-R; r = -0.14; r = -0.14) z-scores controlling for age, sex, and education. MVPA and SDMT (r = 0.05), CVLT-II (r = -0.07), and BVMT-R (r = 0.01) z-scores were not significantly correlated.

CONCLUSION

Cardiorespiratory fitness and MVPA were not associated with cognition in this large progressive MS sample, yet these outcomes represent critical manipulation checks for documenting the success of the CogEx trial. This highlights the importance of examining other exercise-related mechanisms-of-action for improving cognition in progressive MS.

The preliminary effects of moderate aerobic training on cognitive function in people with TBI and significant memory impairment: a proof-of-concept randomized controlled trial

This single-blinded RCT investigated cognitive effects of aerobic exercise in persons with TBI-related memory impairment. Five participants . were randomly assigned to 12-weeks of either supervised moderate intensity aerobic cycling or an active control. Outcome measures included neuropsychological assessments and structural neuroimaging (MRI,). The exercise group demonstrated greater improvements on auditory verbal learning (RAVLT; d=1.54) and processing speed (SDMT; d=1.58). The exercise group showed larger increases in volume of the left hippocampus (d=1.49) and right thalamus (d=1.44). These pilot data suggest that 12-weeks of moderate intensity aerobic cycling may improve memory and processing speed in those with TBI-related memory impairments.

Distinguishing between Fatigue and Fatigability in Multiple Sclerosis

Fatigue is one of the most common debilitating symptoms reported by persons with multiple sclerosis (MS). It reflects feelings of tiredness, lack of energy, low motivation, and difficulty in concentrating. It can be measured at a specific instant in time as a perception that arises from interoceptive networks involved in the regulation of homeostasis. Such ratings indicate the state level of fatigue and likely reflect an inability to correct deviations from a balanced homeostatic state. In contrast, the trait level of fatigue is quantified in terms of work capacity (fatigability), which can be either estimated (perceived fatigability) or measured (objective fatigability). Clinically, fatigue is most often quantified with questionnaires that require respondents to estimate their past capacity to perform several cognitive, physical, and psychosocial tasks. These retrospective estimates provide a measure of perceived fatigability. In contrast, the change in an outcome variable during the actual performance of a task provides an objective measure of fatigability. Perceived and objective fatigability do not assess the same underlying construct. Persons with MS who report elevated trait levels of fatigue exhibit deficits in interoceptive networks (insula and dorsal anterior cingulate cortex), including increased functional connectivity during challenging tasks. The state and trait levels of fatigue reported by an individual can be modulated by reward and pain pathways. Understanding the distinction between fatigue and fatigability is critical for the development of effective strategies to reduce the burden of the symptom for individuals with MS.

Effects of walking exercise training on learning and memory and hippocampal neuroimaging outcomes in MS: A targeted, pilot randomized controlled trial

PURPOSE

The current pilot study involved a single-blind, randomized controlled trial (RCT) on the effects of treadmill walking exercise training compared with an active control condition on learning and memory (L/M) and hippocampal neuroimaging outcomes in 11 fully-ambulatory persons with multiple sclerosis (MS) who demonstrated impairments in new learning.

METHODS

The study protocol is registered at clinicaltrials.gov: NCT03319771 (February 2018). Eleven fully-ambulatory persons with MS-related impairments in new learning were randomly assigned into either 12-weeks of supervised, treadmill walking exercise training or 12-weeks of low-intensity resistive exercise (active control condition). Participants underwent neuropsychological tests of L/M and hippocampal neuroimaging before and after the 12-week study period; outcomes were administered by treatment-blinded assessors.

RESULTS

There were moderate-to-large intervention effects on measures of verbal L/M (η_p² = 0.11, d = 0.63, 95% CI: -0.61, 1.83), whereby those in the intervention condition demonstrated improvement in California Verbal Learning Test-II (CVLT-II) scores compared with the control condition. There were smaller effects on a composite L/M measure (η_p² = 0.02, d = 0.28, 95% CI: -0.93, 1.46). There were large intervention effects on normalized hippocampal volume (η_p² = 0.36, d = 1.13, 95% CI: 0.09, 2.82), whereby hippocampal volume was preserved in the intervention condition, compared with hippocampal atrophy in the control condition. By comparison, there were no intervention effects on hippocampal resting-state functional connectivity.

CONCLUSIONS

Collectively, this study provides initial proof-of-concept data for further examining treadmill walking exercise training as a possible behavioral approach for managing L/M impairment and preserving hippocampal volume as common and debilitating manifestations of MS.

Physical activity may contribute to brain health in multiple sclerosis: An MR volumetric and spectroscopy study

BACKGROUND AND PURPOSE

Physical activity may represent a disease-modifying therapy in persons with multiple sclerosis (pwMS). To date, there is limited research regarding mechanisms based on brain imaging for understanding the beneficial effects of physical activity in pwMS. This study examined the relationship between physical activity levels and thalamic and hippocampal volumes and brain metabolism in pwMS.

METHODS

The sample of 52 pwMS (37.3 ± 9.6 years of age; 35 females, 17 males) underwent a combination of volumetric magnetic resonance imaging and magnetic resonance spectroscopy. Current and lifetime physical activity were assessed using actigraphy and the adapted version of the Historical Activity Questionnaire, respectively.

RESULTS

Positive associations were observed between both actigraphy and self-reported levels of moderate-to-vigorous physical activity (MVPA) and thalamic and hippocampal volumes. Regarding brain metabolism, actigraphy and self-reported levels of MVPA were positively associated with higher hippocampal and thalamic levels of N-acetylaspartate/creatine ratio (NAA/Cr: marker of neural integrity and cell energy state).

CONCLUSIONS

This study provides novel evidence for a positive association between physical activity and thalamic and hippocampal volume and metabolism in pwMS. These findings support the hypothesis that physical activity, particularly MVPA, may serve as a disease-modifying treatment by improving brain health in pwMS.

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.

[The efficacy of active physical exercises in comprehensive cognitive rehabilitation of pediatric and adult patients with multiple sclerosis]

Cognitive dysfunction in multiple sclerosis (MS) is a disabling factor and extends to the processes of memory, attention, verbal and logical thinking, visual-spatial, and motor skills. 40-70% of patients have a decrease in the rate of information processing, dysfunction of executive functions, and decrease in the quality of training. Cognitive dysfunction is also often reduced quality of life with MS. The most common methods of non-drug cognitive function correction are cognitive rehabilitation and exercise. This article reviews current research on the positive effects of regular physical activity on the cognitive functions of adults and children with MS.

The role of the brain in the treatment of multiple sclerosis as a connectomopathy

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) causing a variety of symptoms. Although MS is recognized by the demyelinating process, the axonal injury can occur from the start of the disease and lead to neurodegenerative process in the disease. Although MS appears to damage the brain locally, the progressive and neurodegenerative nature of the disease indicate the general and global brain damage. Various studies have indicated this global damage at all areas of white and gray matter. Moreover, the earlier stages of mentioned disease can affect the structural and functional brain connections. Demyelinating lesions, which are local at first glance, lead to a global damage to the functional connections of the brain. Therefore, it seems that the brain network or brain connectome are broadly affected by this disease; therefore, MS can be referred as a connectomopathy. The drugs used in this disease all seek to suppress or regulate the immune system, and the human brain has always been considered as a therapeutic target. However, if the brain is generally involved in the disease, so the treatment should be general. In fact, the treatment process should target the connectomopathy. One of the methods that can be used to achieve the mentioned goal is attending to the role of the brain in its treatment.

Systematic Review on Exercise Training as a Neuroplasticity-Inducing Behavior in Multiple Sclerosis

Background. Exercise training is associated with functional improvements in persons with multiple sclerosis (MS), perhaps based on neuroplasticity. However, inferences regarding neuroplasticity require observations of exercise-related changes in the central nervous system that explain functional adaptations. This systematic review critically evaluated studies on exercise training, neuroimaging outcomes, and functional outcomes in MS based on consistency with a well-established conceptual model for characterizing exercise training as a possible neuroplasticity-inducing behavior in this population. Methods. We performed targeted and comprehensive searches of multiple databases for papers involving exercise training interventions on functional and neuroimaging outcomes in persons with MS. Acceptable study designs included randomized controlled trials, single-group pre/post designs, and quasi-experimental designs. Four independent reviewers extracted relevant data from each eligible paper on characteristics of participants, exercise interventions, neuroimaging outcomes, functional outcomes, pattern of study results, and potential risks of bias. Results. The literature search returned only 10 papers (involving 8 original interventions) that met eligibility criteria wherein inferences regarding neuroplasticity could be drawn, based on inclusion of neuroimaging and functional endpoints. Within those 10 papers, there is mixed evidence for exercise training as a neuroplasticity-inducing behavior in persons with MS. Conclusions. Such a paucity of evidence supporting exercise-induced neuroplasticity in MS is likely a product of a very small number of papers that do not sufficiently examine hypothesized mechanisms of action. Future research might consider examining specific neural changes that might result from exercise prescriptions that are specifically designed to induce certain functional changes among persons with MS.

Treatment and management of cognitive dysfunction in patients with multiple sclerosis

Cognitive impairment is a common and devastating manifestation of multiple sclerosis (MS). Although disease-modifying therapies have been efficacious for reducing relapse rates in MS, such treatments are ineffective for treating cognitive dysfunction. Alternative treatment approaches for mitigating cognitive problems are greatly needed in this population. To date, cognitive rehabilitation and exercise training have been identified as possible candidates for treating MS-related cognitive impairment; however, cognitive dysfunction is still often considered to be poorly managed in patients with MS. This Review provides a comprehensive overview of recent developments in the treatment and management of cognitive impairment in people with MS. We describe the theoretical rationales, current states of the science, field-wide challenges and recent advances in cognitive rehabilitation and exercise training for treating MS-related cognitive impairment. We also discuss future directions for research into the treatment of cognitive impairment in MS that should set the stage for the inclusion of cognitive rehabilitation and exercise training into clinical practice within the next decade.

Do subcortical gray matter volumes and aerobic capacity account for cognitive-motor coupling in multiple sclerosis?

BACKGROUND

There is evidence of cognitive-motor coupling in multiple sclerosis (MS) such that the slowing of cognitive processing speed correlates with the worsening of walking speed and endurance.

OBJECTIVE

The current study first established the presence of cognitive-motor coupling and second examined the possibility that volumes of subcortical gray matter (SGM) structures and aerobic capacity might explain the coupling of cognitive and motor functions in persons with MS.

METHODS

We included data from 62 persons with clinically definite MS who underwent assessments of cognitive processing speed, walking performance, and aerobic capacity, and completed magnetic resonance imaging (MRI) within 7 days of the aforementioned assessments.

RESULTS

The strong correlations between cognitive processing speed and walking performance were attenuated in magnitude and not statistically significant when controlling for aerobic capacity alone and aerobic capacity and SGM volumes together. The associations between cognitive processing speed and walking performance remained statistically significant when controlling for SGM volumes alone.

CONCLUSION

Aerobic capacity may be an important target for neurorehabilitation-based approaches for managing co-occurring cognitive and motor dysfunction in MS.

Moving exercise research in multiple sclerosis forward (the MoXFo initiative): Developing consensus statements for research

Exercise as a subset of physical activity is a cornerstone in the management of multiple sclerosis (MS) based on its pleotropic effects. There is an exponential increase in the quantity of research on exercise in MS, yet a number of barriers associated with study content and quality hamper rapid progress in the field. To address these barriers and accelerate discovery, a new international partnership of MS-related experts in exercise has emerged with the goal of advancing the research agenda. As a first step, the expert panel met in May 2018 and identified the most urgent areas for moving the field forward, and discussed the framework for such a process. This led to identification of five themes, namely "Definitions and terminology," "Study methodology," "Reporting and outcomes," "Adherence to exercise," and "Mechanisms of action." Based on the identified themes, five expert groups have been formed, that will further (a) outline the challenges per theme and (b) provide recommendations for moving forward. We aim to involve and collaborate with people with MS/MS organizations (e.g. Multiple Sclerosis International Federation (MSIF) and European Multiple Sclerosis Platform (EMSP)) in all of these five themes. The generation of this thematic framework with multi-expert perspectives can bolster the quality and scope of exercise studies in MS that may ultimately improve the daily lives of people with MS.

Protocol for a systematically-developed, phase I/II, single-blind randomized controlled trial of treadmill walking exercise training effects on cognition and brain function in persons with multiple sclerosis

Slowed cognitive processing speed (CPS) is a common and debilitating consequence of multiple sclerosis (MS) that is notoriously difficult to treat. As such, we undertook a systematic line of research that indicated that supervised, progressive treadmill walking exercise (TMWX) training might improve CPS and brain functioning among fully-ambulatory persons with MS. The current study will be the first adequately-powered, single-blind randomized controlled trial (RCT) that examines the efficacy of 12-weeks of TMWX training compared with an active control condition on CPS, thalamocortical brain connectivity (based on resting-state fMRI), and exploratory functional outcomes in 88 fully-ambulatory persons with MS who present with slowed CPS. The intervention condition involves supervised, progressive TMWX training 3 times/week over 12-weeks; this initially involves 15-min of light-to-moderate intensity TMWX that progresses up to 40-min of vigorous intensity TMWX. The active control condition involves supervised, minimal intensity, stretching-and-resistance exercise that will be delivered on the same frequency as the intervention condition. The primary study outcomes involve Symbol Digit Modalities Test performance (i.e., CPS) and fMRI-based measures of thalamocortical resting-state functional connectivity. Exploratory study outcomes involve measures of community participation, activities of daily living, quality of life, and functional mobility. All study outcomes will be administered before and after the 12-week study period by treatment-blinded assessors. If successful, the current study will provide the first Class I evidence for the effects of TMWX training as an approach for improving CPS and its neural correlate, and possibly mitigating the impact of slowed CPS on functional outcomes in MS.

Will behavioral treatments for cognitive impairment in multiple sclerosis become standards-of-care?

Cognitive impairment is common and debilitating in persons with multiple sclerosis (MS), and further is poorly-managed by pharmacotherapy. Cognitive rehabilitation and exercise training have been identified as promising behavioral approaches for managing MS-related cognitive impairment based on systematic reviews and meta-analyses. However, each body of literature is associated with similar sets of methodological shortcomings, as has been identified by periodic systematic reviews and meta-analyses. Thus, there is little generalizability or transportability research supporting either behavioral approach for managing cognitive dysfunction in this population under real-world conditions (i.e., as a standard-of-care). To that end, this paper aims to catalyze the advancement of cognitive rehabilitation and exercise training research in MS, respectively, towards the successful implementation of generalizability/transportability trials. This first involves critical examinations of the respective cognitive rehabilitation and exercise training literatures in MS from a chronological perspective, with particular emphasis on how the fields have each evolved in response to systematic reviews and meta-analyses. Accordingly, the current paper then provides a roadmap for harmonizing research in those areas to systematically and efficiently inform the development of generalizability/transportability trials for behavioral approaches to manage MS-related cognitive dysfunction. This involves the recognition of overlapping facilitators and impediments for progress in each field, including considerations for the implementation of neuroimaging. Ultimately, the provision of such a framework aims to shorten the timeline for research to influence clinical practice and improve the lives of cognitively-impaired persons with MS.