Intervention fidelity and adaptation in a multi-site exercise training intervention for adults with multiple sclerosis.

BACKGROUND: Successful translation of evidence-based exercise training interventions from research to clinical practice depends on the balance of treatment fidelity and adaptability when delivering the exercise program across settings. The current paper summarizes fidelity of study design, provider training, and intervention delivery strategies from best practice recommendations, and reports challenges experienced and adaptations instrumented by behavioral coaches delivering the multi-site Supervised versus Telerehabilitation Exercise Programs for Multiple Sclerosis (STEP for MS) Trial. METHODS: Using a reflexive thematic analysis approach, open-ended survey questions were analyzed to explore experiences of behavioral coaches, transcripts from team meetings among behavioral coaches, and notes from audits of one-on-one sessions between behavioral coaches and participants. RESULTS: Themes related to the fidelity of study design and delivery of the STEP for MS Trial included adaptations to the intervention itself (e.g., completion of virtual supervised exercise sessions with behavioral coaches in place of face-to-face sessions during COVID-19 pandemic restrictions), modification of exercise equipment, and adjustments of program delivery. The adjustments of program delivery reported by behavioral coaches included increasing program fit, maintaining engagement, and addressing participant safety concerns; however, these adaptations did not jeopardize the content of the essential elements of the program model. CONCLUSIONS: The current paper demonstrates that when best practice recommendations are implemented, it is possible to address challenges to study design and evidence-based intervention delivery in ways that adaptations to overcome real-world obstacles can be accomplished without compromising fidelity.

Multisensory integration and white matter pathology: Contributions to cognitive dysfunction.

The ability to simultaneously process and integrate multiple sensory stimuli is paramount to effective daily function and essential for normal cognition. Multisensory management depends critically on the interplay between bottom-up and top-down processing of sensory information, with white matter (WM) tracts acting as the conduit between cortical and subcortical gray matter (GM) regions. White matter tracts and GM structures operate in concert to manage both multisensory signals and cognition. Altered sensory processing leads to difficulties in reweighting and modulating multisensory input during various routine environmental challenges, and thus contributes to cognitive dysfunction. To examine the specific role of WM in altered sensory processing and cognitive dysfunction, this review focuses on two neurologic disorders with diffuse WM pathology, multiple sclerosis and mild traumatic brain injury, in which persistently altered sensory processing and cognitive impairment are common. In these disorders, cognitive dysfunction in association with altered sensory processing may develop initially from slowed signaling in WM tracts and, in some cases, GM pathology secondary to WM disruption, but also because of interference with cognitive function by the added burden of managing concurrent multimodal primary sensory signals. These insights promise to inform research in the neuroimaging, clinical assessment, and treatment of WM disorders, and the investigation of WM-behavior relationships.

Strength Training to Improve Gait in People with Multiple Sclerosis: A Critical Review of Exercise Parameters and Intervention Approaches.

BACKGROUND: There are mixed reports on the effectiveness of strength training to improve gait performance in people with multiple sclerosis (MS), yet the reasons for these inconsistent results are not clear. Therefore, a critical review was conducted to explore dosage, frequency, mode, position, and muscle targets of studies that have included strength training in people with MS. METHODS: An electronic search was conducted through July 2017. Randomized controlled trials involving people with MS were included that implemented strength training with or without other interventions and assessed 1) strength in the lower extremities and/or trunk and 2) gait speed and/or endurance. Strength and gait results were extracted, along with exercise frequency, intensity, duration, mode, position, and muscle targets. RESULTS: Thirteen trials met the inclusion criteria; nine used dosing consistent with recommended guidelines. Overall, six studies reported significant between-group strength improvements, and four reported within-group changes. Four studies reported significant between-group gait improvements for gait speed and/or endurance, and two reported within-group changes. Most exercises were performed on exercise machines while sitting, supine, or prone. The most common intervention target was knee extension. CONCLUSIONS: Studies generally improved strength, yet only two studies reported potentially meaningful between-group changes in gait. Future strength intervention studies designed to improve gait might consider dosing beyond that of the minimum intensity to improve strength and explore muscles targets, positions, and modes that are task-specific to walking.

Perceptual Postural Imbalance and Visual Vertigo.

PURPOSE OF REVIEW: Disorders of posture and balance cause significant patient morbidity, with reduction of quality of life as patients refrain from critical activities of daily living such as walking outside the home and driving. This review describes recent efforts to characterize visual disorders that interact with the neural integrators of positional maintenance and emerging therapies for these disorders. RECENT FINDINGS: Abnormalities of gait and body position sense may be unrecognized by patients but are correlated with focal neurological injury (stroke). Patients with traumatic brain injury can exhibit visual vertigo despite otherwise normal visual functioning. The effect of visual neglect on posture and balance, even in the absence of a demonstrable visual field defect, has been characterized quantitatively through gait analysis and validates the potential therapeutic value of prism treatment in some patients. In addition, the underlying neural dysfunction in visual vertigo has been explored further using functional imaging, and these observations may allow discrimination of patients with structural causes from those whose co-morbid psychosocial disorders may be primarily contributory.

Feasibility of a targeted strengthening program to improve gait in people with multiple sclerosis: a brief report.

This study aims to determine feasibility of strengthening muscles that are important contributors to gait for people with multiple sclerosis, yet are not routinely targeted in the literature. An 8-week strengthening intervention targeted ankle plantarflexion, hip abduction, and trunk muscles using a repeated-measures design. Outcomes included satisfaction, adherence, muscle strength, gait speed (timed 25-foot walk), gait endurance (6-min walk test), and self-reported gait-related participation (Multiple Sclerosis Walking Scale-12). Ten participants (Expanded Disability Status Scale: 3.5-5.5) completed the intervention. All participants were at least 'satisfied'; adherence was 87% (supervised sessions) and 75% (home sessions). All quantitative measures improved: muscle strength (23.1-47.6%, P<0.001-0.039), timed 25-foot walk (-13.4%, P<0.001), 6-min walk test (41.56 m, P=0.019), and Multiple Sclerosis Walking Scale-12 (-10.5, P=0.007). Strengthening of ankle plantarflexion, hip abduction, and trunk muscles was feasible and associated with improvements in gait performance.

Contributions of Ankle, Knee, Hip, and Trunk Muscle Function to Gait Performance in People With Multiple Sclerosis: A Cross-Sectional Analysis.

Background: The relative importance of lower extremity and trunk muscle function to gait in people with multiple sclerosis (MS) is unknown. Objective: This study aimed to investigate the association of lower extremity and trunk muscle function with gait performance in people who have MS and mild-to-moderate disability. Design: This was a cross-sectional, observational study. Methods: Participants were people who had an Expanded Disability Status Scale score of ≤ 5.5. Eleven lower extremity and trunk muscles were assessed using handheld dynamometry or endurance tests. Gait performance was assessed with the Timed 25-Foot (7.62 m) Walk (T25FW) and 6-Minute Walk Test (6MWT). Regression analysis was used to quantify the association between gait outcomes and muscle variables. Results: Seventy-two participants with MS and a mean Expanded Disability Status Scale score of 3.5 (SD = 1.14) were enrolled. Adjusted for age and sex, the multivariate model including hip abduction, ankle plantar flexion, trunk flexion, and knee flexion explained 57% of the adjusted variance in the T25FW; hip abduction, ankle plantar flexion, and trunk flexion explained 61% of the adjusted variance in the 6MWT. The strongest predictors were ankle plantar flexion endurance for the T25FW and hip abduction strength for the 6MWT: a 1-SD increase in ankle plantar flexion (15.2 heel-raise repetitions) was associated with a 0.33-second reduction in the T25WT (95% CI = - 0.71 to - 0.14 seconds); a 1-SD increase in normalized hip abduction strength (0.14 kg/body mass index) was associated with a 54.4-m increase in the 6MWT (28.99 to 79.81 m). Limitations: Different measurement scales for independent variables were included because the muscle function assessment used either force or endurance. Conclusions: For the major muscles in the lower extremity and trunk, hip abduction, ankle plantar flexion, trunk flexion, and knee flexion were the strongest predictors of gait performance.

Efficacy of Balance and Eye-Movement Exercises for Persons With Multiple Sclerosis (BEEMS).

OBJECTIVE: To determine whether a multifaceted vestibular-related rehabilitation program (Balance and Eye-Movement Exercises for Persons with Multiple Sclerosis; BEEMS) improves balance in persons with MS and whether there are differences in outcomes based on brainstem/cerebellar lesion involvement. METHODS: A 2-arm, examiner-blinded, stratified (involvement vs no involvement of brainstem/cerebellar structures), randomized controlled trial was implemented. Eighty-eight participants were allocated to BEEMS or no treatment control. Computerized Dynamic Posturography-Sensory Organization Test (CDP-SOT) measured balance control. The Dizziness Handicap Inventory (DHI), Modified Fatigue Impact Scale (MFIS), and Short Form-36 Health Status Questionnaire (SF-36) were also administered. Linear mixed models were used to investigate the primary and secondary aims. RESULTS: From baseline to 6 weeks, BEEMS participants experienced greater improvements compared to control participants in CDP-SOT composite (model-estimated difference in change 4.9, 95% confidence interval 1.39-8.38, p = 0.006), DHI total (-13.5, -17.7 to -7.25, p < 0.0001), MFIS total (-11.4, -15.7 to -7.0, p < 0.0001), SF-36 Mental (5.6, 2.43-8.71, p = 0.0006), and SF-36 Physical (3.5, 1.12-5.81, p = 0.004) scores and from baseline to 14 weeks in CDP-SOT composite (8.3, 4.73-11.9, p < 0.0001), DHI total (-13.9, -19.3 to -8.62, p < 0.0001), MFIS total (-12.3, -16.7 to -7.79, p < 0.0001), SF-36 Mental (3.9, 0.70-7.16, p = 0.02), and SF-36 Physical (3.2, 0.79-5.62, p = 0.01) scores. From baseline to 6 weeks, BEEMS participants with brainstem/cerebellar lesion involvement experienced greater improvements compared to those without in CDP-SOT composite (5.26, 0.34-10.2, p = 0.04) and MFIS total (-7.6, -14.0 to -1.33, p = 0.02) scores. CONCLUSION: BEEMS improved multiple outcomes regardless of whether brainstem/cerebellar lesions were present, supporting the generalizability of BEEMS for ambulatory people with MS who have at least minimally impaired balance and fatigue. CLINICAL TRIALSGOV IDENTIFIER: NCT01698086. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that BEEMS training improves dynamic posturography-based balance, dizziness, fatigue, and quality of life in persons with MS.

Persistent Symptoms and Objectively Measured Balance Performance Among OEF/OIF Veterans With Remote Mild Traumatic Brain Injury.

OBJECTIVE: To investigate linear relationships between dizziness, fatigue, and depression and posttraumatic stress disorder (PTSD) and objectively measured balance performance in Veterans with remote mild traumatic brain injury (mTBI). SETTING: Academic laboratory; Veterans Affairs Medical Center. PARTICIPANTS: Thirty Veterans (28 men) who served in Iraq/Afghanistan and whose most recent mTBI was sustained more than 6 months prior to enrollment. DESIGN: Cross-sectional, observational trial. MAIN MEASURES: The Computerized Dynamic Posturography-Sensory Organization Test (CDP-SOT) and the Community Balance and Mobility (CB&M) scale measured balance. Dizziness (Dizziness Handicap Inventory), fatigue (Modified Fatigue Impact Scale), depression-related symptoms (Beck Depression Inventory-II), and PTSD-related symptoms (PTSD Checklist 5) were also measured. RESULTS: Objectively measured balance, CDP-SOT composite, was impaired (mean score of 67.9). CDP-SOT scores correlated with dizziness (r = -0.53; P = .002), fatigue (r = -0.38; P = .03), depression (r = -0.55; P = .001), and PTSD symptoms (r = -0.53; P = .002). Dizziness, time since most recent mTBI, and PTSD symptoms and depression combined explained significant variability in CDP-SOT scores (R = 0.46; P = .003), as did fatigue depression and PTSD symptoms (R = 0.33; P = .01). CONCLUSIONS: Impaired balance was identified among the cohort. Findings suggest that dizziness, fatigue, depression and PTSD, and time since most recent mTBI may influence balance performance. Additional research is needed to identify the potentially interrelated natural histories of these co-occurring symptoms.

Pulse Width Does Not Influence the Gains Achieved With Neuromuscular Electrical Stimulation in People With Multiple Sclerosis: Double-Blind, Randomized Trial.

BACKGROUND: Multiple sclerosis (MS) eventually compromises the walking ability of most individuals burdened with the disease. Treatment with neuromuscular electrical stimulation (NMES) can restore some functional abilities in persons with MS, but its effectiveness may depend on stimulus-pulse duration. OBJECTIVE: To compare the effects of a 6-week intervention with narrow- or wide-pulse NMES on walking performance, neuromuscular function, and disability status of persons with relapsing-remitting MS. METHODS: Individuals with MS (52.6 ± 7.4 years) were randomly assigned to either the narrow-pulse (n = 13) or wide-pulse (n = 14) group. The NMES intervention was performed on the dorsiflexor and plantar flexor muscles of both legs (10 minutes each muscle, 4 s on and 12 s off) at a tolerable level for 18 sessions across 6 weeks. Outcomes were obtained before (week 0) and after (week 7) the intervention and 4 weeks later (week 11). RESULTS: There was no influence of stimulus-pulse duration on the outcomes ( P > .05); thus, the data were collapsed across groups. The NMES intervention improved ( P < .05) gait speed and walking endurance, dorsiflexor strength in the more-affected leg, plantar flexor strength in the less-affected leg, force control for plantar flexors in the less-affected leg, and self-reported levels of fatigue and walking limitations. CONCLUSION: There was no influence of stimulus-pulse duration on the primary outcomes (gait speed and walking endurance). The 6-week NMES intervention applied to the lower leg muscles of persons with mild to moderate levels of disability can improve their walking performance and provide some symptom relief.

Psychometric Properties of a Clinical Strength Assessment Protocol in People with Multiple Sclerosis.

BACKGROUND: Strength training in people with multiple sclerosis (MS) is an important component of rehabilitation, but it can be challenging for clinicians to quantify strength accurately and reliably. This study investigated the psychometric properties of a clinical strength assessment protocol using handheld dynamometry and other objective, quantifiable tests for the lower extremities and trunk in people with MS. METHODS: This study determined discriminant validity between 25 participants with MS and 25 controls and between participants with MS who had higher versus lower disability; test-retest reliability across 7 to 10 days; and response stability. The protocol included handheld dynamometry measurements of ankle dorsiflexion, knee flexion and extension; hip flexion, extension, abduction, and adduction; and trunk lateral flexion. Muscular endurance tests were used to measure trunk extension, trunk flexion, and ankle plantarflexion. RESULTS: The protocol discriminated between participants with MS and controls for all muscles tested (P < .001-.003). The protocol also discriminated between low- and moderate-disability groups (P = .001-.046) for 80% of the muscles tested. Test-retest reliability intraclass correlation coefficients were high (0.81-0.97). Minimal detectable change as a percentage of the mean was 13% to 36% for 85% of muscles tested. CONCLUSIONS: This study provides evidence for the discriminant validity, test-retest reliability, and response stability of a strength assessment protocol in people with MS. This protocol may be useful for tracking outcomes in people with MS for clinical investigations and practice.

Reliability and Validity of the Computerized Dynamic Posturography Sensory Organization Test in People with Multiple Sclerosis.

BACKGROUND: People with multiple sclerosis (MS) frequently have impaired postural control (balance). Psychometric properties of clinical tests of balance for individuals with MS, including the computerized dynamic posturography sensory organization test (CDP-SOT), are poorly understood. This study aimed to determine the reliability and discriminant validity of the CDP-SOT in people with MS. METHODS: The CDP-SOT was performed on 30 participants with MS. A 2-week-interval, repeated-measures (sessions 1 and 2) design was implemented to investigate test-retest reliability of the CDP-SOT and the ability of the CDP-SOT to discriminate between participants with lower versus higher disability. Self-reported disability level was based on Patient-Determined Disease Steps (PDDS) scale scores: lower (PDDS scale score, 0-3; n = 17) and higher (PDDS scale score, 4-6; n = 13). RESULTS: All six conditions of the CDP-SOT had good-to-excellent reliability (interclass correlation coefficients, 0.70-0.90) and excellent reliability for composite scores (0.90). Composite scores were significantly greater in the lower-disability group versus the higher-disability group at session 1 (70.89 vs. 48.60, P = .001) and session 2 (74.82 vs. 48.85, P = .002). CONCLUSIONS: The CDP-SOT is a reliable measure of balance and accurately differentiates disability status in people with MS. Collectively, the results support clinical application of the CDP-SOT as a reliable and valid measure of disease-related progression of impaired balance related to sensory integration and its utility in determining changes in balance in response to treatment.

Gaze stabilization and dynamic visual acuity in people with multiple sclerosis.

BACKGROUND: The functional capacity of the vestibulo-ocular reflex (VOR) is not well understood in people with multiple sclerosis (MS). OBJECTIVE: To determine the psychometric properties of computerized Gaze Stabilization Test (GST) and Dynamic Visual Acuity Test (DVAT) in people with MS. METHODS: This cross-sectional study determined discriminant validity of the GST and DVAT between 15 healthy controls and 30 participants with MS, and between participants with MS who had higher versus lower disability. This study also determined same-day and between-session test-retest reliability, and concurrent validity with patient-reported outcomes (PROs) of balance, dizziness, and fatigue. RESULTS: GST (p < 0.001) and DVAT (p = 0.001) scores were lower in participants with MS compared to controls. GST (p = 0.035) but not DVAT (p = 0.313) scores were lower in those with higher compared to lower disability. Test-retest reliability intraclass correlation coefficients (ICC (2,1)) were fair-to-good for the GST (0.48 to 0.74) and DVAT (0.47 to 0.60). PROs correlated significantly with GST, but not DVAT scores. CONCLUSIONS: This study provides initial evidence that the functional capacity of the VOR is impaired in people with MS as measured by the GST and DVAT. Further investigation is warranted to determine usefulness of both measures as outcomes for people with MS.

Cognitive-Motor Related Brain Activity During Walking: Differences Between Men and Women With Multiple Sclerosis.

OBJECTIVE: To determine if sex differences in glucose uptake, a marker of brain activity, are present in brain regions that facilitate walking performance in persons with multiple sclerosis (MS). DESIGN: Cross-sectional, observational pilot. SETTING: University laboratory. PARTICIPANTS: Positron emission tomography with fluorine-18-labeled deoxyglucose (FDG) was performed on persons with MS and healthy controls (4 men and 4 women per group; N=16) after a 15-minute walking test. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Brain activity was quantified as the mean standardized uptake value (SUV). RESULTS: The mean SUV was significantly lower in the thalamus (P=.029) and cerebellum (P=.029) for men with MS compared with women with MS, but not for the prefrontal (P=.057) or frontal (P=.057) cortices. Similar nonsignificant trends were found for healthy controls. No mean SUV group × sex interaction effects were found between the MS and healthy control groups (all P>.05). CONCLUSIONS: To our knowledge, this is the first study of brain activity sex differences based on FDG uptake in persons with MS during walking. Significantly less FDG uptake in the thalamus and cerebellum brain regions important for walking performance was found in men with MS compared with women with MS; however, these comparisons were not significantly different in the healthy control group. No differences in FDG uptake were found between the MS and healthy control groups in any of the brain regions examined. Results from this study provide pilot data for larger studies aimed at identifying underlying mechanisms responsible for accelerated disability in men with MS.

Core muscle characteristics during walking of patients with multiple sclerosis.

The purpose of this study was to investigate core muscle characteristics during walking in patients with multiple sclerosis (MS). Eight patients (4 men) with relapsing-remitting MS (aged 44.9 +/- 8.6 yr) and sex-matched controls (37.9 +/- 8.4 yr) walked on a treadmill for 15 min at a self-selected speed. Positron emission tomography/computed tomography imaging was used to measure core muscle activity immediately after walking based on glucose uptake. Activity was not different between the MS and control group for any of the identified muscles (p > 0.28). Within the MS group, side differences in activity were identified in the lateral flexor group, the external and internal obliques, and the rectus abdominis (p < 0.05), with the less-affected side being activated more. Furthermore, greater muscle volume was found on the more-affected side of the transversus abdominis, quadratus lumborum, and the low-back extensor group (p < 0.03). These muscle characteristics suggest patients with MS utilize compensatory mechanisms during walking to maintain balance and posture. These strategies likely result in increased muscle energy cost and early fatigability.

Effects of vestibular rehabilitation on multiple sclerosis-related fatigue and upright postural control: a randomized controlled trial.

BACKGROUND: Fatigue and impaired upright postural control (balance) are the 2 most common findings in people with multiple sclerosis (MS), with treatment approaches varying greatly in effectiveness. OBJECTIVES: The aim of this study was to investigate the benefits of implementing a vestibular rehabilitation program for the purpose of decreasing fatigue and improving balance in patients with MS. DESIGN: The study was a 14-week, single-blinded, stratified blocked randomized controlled trial. SETTING: Measurements were conducted in an outpatient clinical setting, and interventions were performed in a human performance laboratory. PATIENTS: Thirty-eight patients with MS were randomly assigned to an experimental group, an exercise control group, or a wait-listed control group. INTERVENTION: The experimental group underwent vestibular rehabilitation, the exercise control group underwent bicycle endurance and stretching exercises, and the wait-listed control group received usual medical care. MEASUREMENTS: Primary measures were a measure of fatigue (Modified Fatigue Impact Scale), a measure of balance (posturography), and a measure of walking (Six-Minute Walk Test). Secondary measures were a measure of disability due to dizziness or disequilibrium (Dizziness Handicap Inventory) and a measure of depression (Beck Depression Inventory-II). RESULTS: Following intervention, the experimental group had greater improvements in fatigue, balance, and disability due to dizziness or disequilibrium compared with the exercise control group and the wait-listed control group. These results changed minimally at the 4-week follow-up. Limitations The study was limited by the small sample size. Further investigations are needed to determine the underlying mechanisms associated with the changes in the outcome measures due to the vestibular rehabilitation program. CONCLUSION: A 6-week vestibular rehabilitation program demonstrated both statistically significant and clinically relevant change in fatigue, impaired balance, and disability due to dizziness or disequilibrium in patients with MS.