Neuroplasticity of the sensorimotor neural network associated with walking aid training in people with multiple sclerosis

A walking aid selection, training, and education program (ADSTEP) to prevent falls in multiple sclerosis: A randomized controlled trial

BACKGROUND

People with multiple sclerosis (MS) fall frequently. Poor walking aid selection, fit, and use contribute to falls in those who use walking aids.

OBJECTIVES

To determine if the Assistive Device Selection, Training, and Education Program (ADSTEP), with six weekly one-on-one virtual sessions with a physical therapist prevents falls and improves other outcomes in people with MS who use walking aids but still fall.

METHODS

A total of 78 people were randomized to ADSTEP or control. Participants recorded falls daily through 6 months post-intervention. Other outcomes were assessed at baseline, intervention completion, and 6 months later. Outcomes were compared between groups.

RESULTS

The ADSTEP group's mean fall rate (falls/person/month) decreased from baseline to intervention completion (ADSTEP = -0.75, control = +0.90, p < 0.001) and to 6 months later (ADSTEP = -1.02, control = +0.03, p = 0.017) compared to controls. At 6 months, the ADSTEP group had improved physical activity (days/week walking ⩾ 10 minutes at a time: ADSTEP = +0.69, control = -0.58, p = 0.007; minutes/day sitting: ADSTEP = -57, control = +56, p = 0.009) and walking aid fit (proportion with good fit: ADSTEP = +25%, control = -13%, p = 0.018) compared to controls.

CONCLUSIONS

ADSTEP likely reduces falls, increases physical activity, and improves walking aid fit in people with MS who use walking aids and fell in the past year.

Task-oriented training for gait rehabilitation in people with multiple sclerosis: A systematic review

OBJECTIVES

This systematic review aims to examine the effects of task-oriented (TO) training on gait function in people with multiple sclerosis (MS) and to determine the most effective TO training protocol.

METHODS

We searched PubMed, Web of Science, Scopus, EMBASE, REHABDATA, and PEDro for studies that examined the effects of TO on gait ability (i.e., gait velocity, gait endurance, functional mobility) in people with MS from 1971 to October 2022. The quality of the selected studies was estimated using the Physiotherapy Evidence Database (PEDro) scale.

RESULTS

Nine studies met the eligibility criteria. A total of 199 people with MS, 58.79% of whom were women, were included. Five studies revealed "good" quality, one revealed "fair", and three exhibited "poor" quality. Four studies administered TO training alone, and five combined TO training with conventional physiotherapy. The selected studies showed varied results for the influences of TO training on gait ability in people with MS.

CONCLUSIONS

The evidence for the impact of TO training on people with MS was limited. The optimal TO training protocol stills vague. Further studies with larger sample sizes are needed.

Advanced neuroimaging techniques to explore the effects of motor and cognitive rehabilitation in multiple sclerosis

INTRODUCTION

Progress in magnetic resonance imaging (MRI) technology and analyses is improving our comprehension of multiple sclerosis (MS) pathophysiology. These advancements, which enable the evaluation of atrophy, microstructural tissue abnormalities, and functional plasticity, are broadening our insights into the effectiveness and working mechanisms of motor and cognitive rehabilitative treatments.

AREAS COVERED

This narrative review with selected studies discusses findings derived from the application of advanced MRI techniques to evaluate structural and functional neuroplasticity modifications underlying the effects of motor and cognitive rehabilitative treatments in people with MS (PwMS). Current applications as outcome measure in longitudinal trials and observational studies, their interpretation and possible pitfalls and limitations in their use are covered. Finally, we examine how the use of these techniques could evolve in the future to improve monitoring of motor and cognitive rehabilitative treatments.

EXPERT COMMENTARY

Despite substantial variability in study design and participant characteristics in rehabilitative studies for PwMS, improvements in motor and cognitive functions accompanied by structural and functional brain modifications induced by rehabilitation can be observed. However, significant enhancements to refine rehabilitation strategies are needed. Future studies in this field should strive to implement standardized methodologies regarding MRI acquisition and processing, possibly integrating multimodal measures. This will help identifying relevant markers of treatment response in PwMS, thus improving the use of rehabilitative interventions at individual level. The combination of motor and cognitive strategies, longer periods of treatment, as well as adequate follow-up assessments will contribute to enhance the quality of evidence in support of their routine use.

Systematic review of cognitive reserve in multiple sclerosis: Accounting for physical disability, fatigue, depression, and anxiety

BACKGROUND

Cognitive reserve (CR) describes an individual's ability to adapt cognitive processes in response to brain atrophy, and has been reported to explain some of the discrepancy between brain atrophy and cognitive functioning outcomes in multiple sclerosis (MS). CR in MS is typically investigated by assessing an individual's pre- and/or post-diagnosis enrichment, which includes premorbid intellectual abilities, educational level, occupational attainment, and engagement in cognitively enriching leisure activities. Common MS symptoms (e.g., physical disability, fatigue, depression, anxiety) may impact an individual's ability to engage in various CR-enhancing activities post-diagnosis. It is unknown to what extent these MS symptoms have been taken into account in MS research on CR. As such, we identified whether studies assessed CR using measures of premorbid or continuous (including post-diagnosis) enrichment. For studies investigating continuous enrichment, we identified whether studies accounted for MS-impact, which MS symptoms were accounted for, and how, and whether studies acknowledged MS symptoms as potential CR-confounds.

METHODS

Three electronic databases (PsycINFO, PubMed, Scopus) were searched. Eligible studies investigated CR proxies (e.g., estimated premorbid intellectual abilities, vocabulary knowledge, educational level, occupational attainment, cognitively enriching leisure activities, or a combination thereof) in relation to cognitive, brain atrophy or connectivity, or daily functioning outcomes in adult participants with MS. We extracted data on methods and measures used, including any MS symptoms taken into account. Objectives were addressed using frequency analyses and narrative synthesis.

RESULTS

115 studies were included in this review. 47.8% of all studies investigated continuous enrichment. Approximately half of the studies investigating continuous enrichment accounted for potential MS-impact in their analyses, with only 31.0% clearly identifying that they treated MS symptoms as potential confounds for CR-enhancement. A narrative synthesis of studies which investigated CR with and without controlling statistically for MS-impact indicated that accounting for MS symptoms may impact findings concerning the protective nature of CR.

CONCLUSION

Fewer than half of the studies investigating CR proxies in MS involved continuous enrichment. Just over half of these studies accounted for potential MS-impact in their analyses. To achieve a more complete and accurate understanding of CR in MS, future research should investigate both pre-MS and continuous enrichment. In doing so, MS symptoms and their potential impact should be considered. Establishing greater consistency and rigour across CR research in MS will be crucial to produce an evidence base for the development of interventions aimed at improving quality of care and life for pwMS.

Gait stability reflects motor tracts damage at early stages of multiple sclerosis

Background:

Gait in people with multiple sclerosis (PwMS) is affected even when no changes can be observed on clinical examination. A sensitive measure of gait deterioration is stability; however, its correlation with motor tract damage has not yet been established.

Objective:

To compare stability between PwMS and healthy controls (HCs) and determine associations between stability and diffusion magnetic resonance image (MRI) measures of axonal damage in selected sensorimotor tracts.

Methods:

Twenty-five PwMS (Expanded Disability Status Scale (EDSS) < 2.5) and 15 HCs walked on a treadmill. Stability from sacrum (LDESAC), shoulder (LDESHO) and cervical (LDECER) was calculated using the local divergence exponent (LDE). Participants underwent a 7T-MRI brain scan to obtain fibre-specific measures of axonal loss within the corticospinal tract (CST), interhemispheric sensorimotor tract (IHST) and cerebellothalamic tract (CTT). Correlation analyses between LDE and fibre density (FD) within tracts, fibre cross-section (FC) and FD modulated by FC (FDC) were conducted. Between-groups LDE differences were analysed using analysis of variance (ANOVA).

Results:

Correlations between all stability measures with CSTFD, between CSTFDC with LDESAC and LDECER, and LDECER with IHSTFD and IHSTFDC were significant yet moderate ( R < −0.4). Stability was significantly different between groups.

Conclusions:

Poorer gait stability is associated with corticospinal tract (CST) axonal loss in PwMS with no-to-low disability and is a sensitive indicator of neurodegeneration.

Neuroplasticity and Motor Rehabilitation in Multiple Sclerosis: A Systematic Review on MRI Markers of Functional and Structural Changes

Background: Motor rehabilitation is routinely used in clinical practice as an effective method to reduce progressive disability gain in multiple sclerosis (MS), but rehabilitation approaches are typically unstandardized, and only few studies have investigated the impact of rehabilitation on brain neuroplasticity. Objective: To summarize and critically analyze studies applying MRI markers of functional connectivity and structural changes to assess the effect of motor rehabilitation on brain neuroplasticity in MS. Methods: Literature search was performed using PubMed and EMBASE, selecting studies having as a subject motor rehabilitation and advanced MRI techniques investigating neuroplasticity in adult patients affected by MS. Results: Seventeen out of 798 papers were selected, of which 5 applied structural MRI (4 diffusion tensor imaging, 1 volumetric measurements), 7 applied functional fMRI (5 task-related fMRI, 2 resting-state fMRI) whereas the remaining 5 applied both structural and functional imaging. Discussion: The considerable data heterogeneity and the small sample sizes characterizing the studies limit interpretation and generalization of the results. Overall, motor rehabilitation promotes clinical improvement, paralleled by positive adaptive brain changes, whose features and extent depend upon different variables, including the type of rehabilitation approach. MRI markers of functional and structural connectivity should be implemented in studies testing the efficacy of motor rehabilitation. They allow for a better understanding of neuroplastic mechanisms underlying rehabilitation-mediated clinical achievements, facilitating the identification of rehabilitation strategies tailored to patients' needs and abilities.

The neural underpinnings of motor learning in people with neurodegenerative diseases: A scoping review

Chronic progressive neurodegenerative diseases (NDD) cause mobility and cognitive impairments that disrupt quality of life. The learning of new motor skills, motor learning, is a critical component of rehabilitation efforts to counteract these chronic progressive impairments. In people with NDD, there are impairments in motor learning which appear to scale with the severity of impairment. Compensatory cortical activity plays a role in counteracting motor learning impairments in NDD. Yet, the functional and structural brain alterations associated with motor learning have not been synthesized in people with NDD. The purpose of this scoping review is to explore the neural alterations of motor learning in NDD. Thirty-five peer-reviewed original articles met the inclusion criteria. Participant demographics, motor learning results, and brain imaging results were extracted. Distinct motor learning associated compensatory processes were identified across NDD populations. Evidence from this review suggests the success of motor learning in NDD populations depends on the neural alterations and their interaction with motor learning networks, as well as the progression of disease.

Impact of cognitive reserve on dance intervention-induced changes in brain plasticity

Dance is a complex sensorimotor activity with positive effects on physical fitness, cognition, and brain plasticity in the aging population. We explored whether individual levels of cognitive reserve (CR) proxied by education moderate dance intervention (DI)-induced plasticity assessed by resting-state functional connectivity (rs-FC) changes of the sensorimotor network (SMN), and between the dorsal attention network (DAN) and anterior default mode network (aDMN). Our cohort consisted of 99 subjects, randomly assigned to either a DI group who underwent a 6-month intervention (n = 49, M_age = 69.02 ± 5.40) or a control group (n = 50, M_age = 69.37 ± 6.10). Moderation analyses revealed that CR moderated DI-induced increase of the SMN rs-FC with significant changes observed in participants with ≥ 15 years of education (b = 0.05, t(62) = 3.17, p = 0.002). Only DI alone was a significant predictor of the DAN-aDMN crosstalk change (b = 0.06, t(64) = 2.16, p = 0.035). The rs-FC increase in the SMN was correlated with an improved physical fitness measure, and changes in the DAN-aDMN connectivity were linked to better performance on figural fluency. Consistent with the passive CR hypothesis, we observed that CR correlated only with baseline behavioral scores, not their change.

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.

Efficacy of core stability versus task oriented trainings on balance in ataxic persons with multiple sclerosis. A single blinded randomized controlled trial

BACKGROUND

Balance and ataxic symptoms are commonly encountered in people with multiple sclerosis (PwMS). Many intervention approaches have been proposed to address balance in PwMS. The purpose of this study was to investigate the efficacy of adding core stability versus task oriented trainings on traditional approaches on balance in ataxic PwMS.

METHODS

Forty five ataxic relapsing-remitting PwMS from both sexes were randomly assigned into three identical groups. Control group (CG) treated with conventional balance exercise program; study groups I (GI) and II (GII) received respectively additional training using core stability exercises and task oriented trainings. Outcome measures recorded pre and post study period included stability index (SI), anterior posterior stability index (APSI), and mediolateral stability index (MLSI) using Biodex stability system in addition to the Berg balance scale (BBS).

RESULTS

Post treatment, the results indicated significant improvement in (SI) and (APSI) (p<0.05), and non-significant improvement (p>0.05) in (MLSI) and BBS in CG. In GI and GII there was a significant improvement in all balance measures (p<0.05). Comparison of post treatment results between groups indicated a significant improvement of GII compared to CG in all study measures, GI showed non- significant difference in all balance measures compared to the CG(P>0.05).

CONCLUSION

In PwMS balance rehabilitation should be multimodal; core stability exercises and task-oriented training in addition to conventional balance training are effective to improve balance and should be considered as an essential part of the training program for balance rehabilitation in ataxic PwMS. Task-oriented training in addition to conventional balance rehabilitation seem to be a favorable approach.

The patients' perspective on the perceived difficulties of dual-tasking: development and validation of the Dual-task Impact on Daily-living Activities Questionnaire (DIDA-Q)

BACKGROUND

Everyday-life activities often require performing dual tasks (DT), with consequent possible occurrence of motor-cognitive or motor-motor interference. This could reduce quality of life, in particular in people with neurological diseases. However, there is lack of validated tools to assess the patients' perspective on DT difficulties in this population. Therefore, we developed the Dual-task Impact on Daily-living Activities-Questionnaire (DIDA-Q) and tested its psychometric properties in people with multiple sclerosis (PwMS).

METHODS

Items were generated based on existing scales, DT paradigms used in previous studies and the opinion of a multi-stakeholder group, including both experts and PwMS. Twenty DT constituted the preliminary version of the DIDA-Q which was administered to 230 PwMS. The psychometric properties of the scale were evaluated including internal consistency, validity and reliability.

RESULTS

Nineteen items survived after exploratory factor analysis, showing a three-factor solution which identifies the components mostly contributing to DT perceived difficulty (i.e., balance and mobility, cognition and upper-limb ability). The DIDA-Q appropriately fits the graded response model, with first evaluations supporting internal consistency (Cronbach's alpha=0.95), validity (70% of the hypotheses for convergent and discriminant constructs confirmed) and reliability (intraclass correlation coefficients=0.95) of this tool.

CONCLUSION

The DIDA-Q could be used in research and clinical settings to discriminate individuals with low vs. high cognitive-motor or motor-motor interference, and to develop and evaluate the efficacy of personalized DT rehabilitative treatments in PwMS.

Brain activity changes following neuroproprioceptive "facilitation, inhibition" physiotherapy in multiple sclerosis: a parallel group randomized comparison of two approaches

BACKGROUND

Imaging methods bring new possibilities for describing the brain plasticity processes that underly the improvement of clinical function after physiotherapy in people with multiple sclerosis (pwMS). Although these processes have been described mainly in connection with task-oriented physiotherapy and aerobic training, they have not been properly verified in neuroproprioceptive "facilitation, inhibition" (facilitation) approaches.

AIM

The study determined whether facilitation physiotherapy could enhance brain plasticity, compared two facilitation methods and looked for any relation to clinical improvement in pwMS.

DESIGN

The study was designed as parallel group randomized comparison of two kinds of physiotherapeutic interventions referred to healthy controls.

SETTING

Thirty-eight outpatients were involved in the study.

POPULATION

The study had 80 participants (38 pwMS and 42 healthy controls).

METHODS

PwMS were divided into two groups and underwent a two-month physiotherapy program: Vojta reflex locomotion (VRL) or Motor program activating therapy (MPAT), (1 hour, twice a week). Functional magnetic resonance imaging (fMRI) and clinical examination was performed before and after therapy. Healthy controls underwent one fMRI examination.

RESULTS

Physiotherapy in pwMS leads to extension of brain activity in specific brain areas (cerebellum, supplementary motor areas and premotor areas) in connection with the improvement of the clinical status of individual patients after therapy (P=0.05). Greater changes (P=0.001) were registered after MPAT than after VRL. The extension of activation was a shift to the examined activation of healthy controls, whose activation was higher in the cerebellum and secondary visual area (P=0.01).

CONCLUSIONS

Neuroproprioceptive "facilitation, inhibition" physiotherapy may enhance brain activity and could involve processes connected with the processing of motion activation.

CLINICAL REHABILITATION IMPACT

The study showed that facilitation approach can modulate brain activity. This could be useful for developing of effective physiotherapeutic treatment in MS.

Beyond clinical changes: Rehabilitation-induced neuroplasticity in MS

BACKGROUND

Neural plasticity represents the substrate by which the damaged central nervous system (CNS) re-learns lost behaviors in response to rehabilitation. In persons with multiple sclerosis (MS), rehabilitation can therefore exploit the potential of neural plasticity to restore CNS functions beyond the spontaneous mechanisms of recovery from MS-related damage.

METHODS

Here, we reviewed the currently available evidence on the occurrence of mechanisms of structural and functional plasticity following rehabilitation, motor, and/or cognitive training. We presented both data gained from basic laboratory research on animal models and data on persons with MS obtained by advanced magnetic resonance imaging (MRI) techniques.

RESULTS

Studies on physical and environmental enrichment in experimental MS models showed beneficial effects mediated by both immune modulation and activity-dependent plasticity, lowering tissue destruction and restoring of CNS network function. Translational researches in MS people demonstrated structural and/or functional MRI changes after various interventions, but their heterogeneity and small sample sizes (5-42 patients) raise concerns about the interpretation and generalization of the obtained results.

DISCUSSION

We highlighted the limitations of published studies, focusing on the knowledge gaps to be filled in terms of neuropathological correlations between changes detected in animal models and changes detected in vivo by neuroimaging.

Neuroprotective effects of exercise in people with progressive multiple sclerosis (Exercise PRO-MS): study protocol of a phase II trial

Background

Neurodegeneration, rather than inflammation, plays a key role in the progressive phase of multiple sclerosis (MS). Current disease modifying treatment options for people with progressive MS (PMS) do not specifically target neurodegeneration. Preliminary evidence suggests that exercise therapy might have neuroprotective effects. However, neuroprotective effect studies of exercise interventions in PMS are scarce and the possible mode of action underlying neuroprotective effects of exercise are unknown and need to be elucidated. The main aim of this phase II trial is to assess whether progressive resistance training (PRT) and high intensity interval training (HIIT), can slow down neurodegeneration in people with PMS.

Methods

In a single-blinded phase II clinical trial with an extended baseline period, 60 people with PMS will be randomly assigned to PRT or HIIT. The participants should have had a relapse onset of MS with confirmed disease progression, however still ambulatory. The duration of the study is 48 weeks, consisting of 16 weeks baseline period (no intervention), 16 weeks intervention and 16 weeks follow-up. Patient-tailored training will be performed 3 times per week for one hour in groups, led by an experienced physiotherapist. The primary outcome measure is neurodegeneration, measured as whole brain atrophy on magnetic resonance imaging (MRI). Secondary outcome parameters will include other biomarkers associated with neurodegeneration (i.e. regional brain atrophy, lesion load, white matter integrity, resting state functional connectivity, blood biomarkers (brain derived neurotrophic factor (BDNF) and serum neurofilament light (sNFL)), patient functioning (physical and cognitive) and cardiovascular risk factors.

Discussion

Besides the primary outcome measures, this study will examine a large variety of biomarkers associated with neurodegeneration after an exercise intervention. Combining outcome parameters may help to elucidate the mode of action underlying neuroprotective effects of exercise.

Trial registration

This trial is prospectively registered at the Dutch Trial Registry (number NL8265, date 06-01-2020).

Cortical topological network changes following optic neuritis

OBJECTIVE

To differentiate between visual cortical network topology changes following optic neuritis (ON) stemming from different inflammatory disease types, we used mathematical graph theory-based tools to analyze functional imaging data.

METHODS

Sixty-two patients were recruited into this cross-sectional study, 23 of whom had neuromyelitis optica spectrum disorder (NMOSD) with ON, 18 with clinically isolated syndrome (CIS)-ON, and 21 with other CIS episodes. Twenty-six healthy controls (HCs) were also recruited. All participants underwent resting-state functional MRI. Visual networks were defined using 50 visual regions of interest. Analysis included graph theory metrics, including degree, density, modularity, and local and global efficiency.

RESULTS

Visual network density shows decreased connectivity in all patient groups compared with controls. A higher degree of connections is seen in both ON groups (CIS and NMOSD) compared with the the non-ON group. This pattern is most pronounced in dorsal-lateral regions. Information transfer efficiency and modularity were reduced in both CIS groups, but not in the NMOSD group, compared with the HC group.

CONCLUSIONS

Visual network density appears affected by the neurologic deficit sustained (ON), and connectivity changes are more evident in dorsal-lateral regions. Efficiency and modularity appear to be associated with the specific disease type (CIS vs NMOSD). Thus, topological cortical changes in the visual system are associated with the type of neurologic deficit within the limits set on them by the underlying pathophysiology. We suggest that cortical patterns of activity should be considered in the outcome of the patients despite the localized nature of ON.