Jeffrey R. Hebert

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.

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.

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.

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.

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.