Arm Ergometry to Improve Mobility in Progressive Multiple Sclerosis (AMBOS)-Results of a Pilot Randomized Controlled Trial

Abstract

Background: Walking disability is one of the most frequent and burdening symptoms of progressive multiple sclerosis (MS). Most of the exercise intervention studies that showed an improvement in mobility performance were conducted in low to moderately disabled relapsing-remitting MS patients with interventions using the legs. However, MS patients with substantial walking disability hardly can perform these tasks. Earlier work has indicated that aerobic arm training might also improve walking performance and could therefore be a therapeutic option in already moderately disabled progressive MS patients. Methods: Patients with progressive MS and EDSS 4-6.5 were randomized using a computer-generated algorithm list to either a waitlist control group (CG) or an intervention group (IG). The IG performed a 12-week home-based, individualized arm ergometry exercise training program. Maximum walking distance as measured by the 6-min walking test (6MWT) was the primary endpoint. Secondary endpoints included aerobic fitness, other mobility tests, cognitive functioning, as well as fatigue and depression. Results: Of n = 86 screened patients, 53 with moderate disability (mean EDSS 5.5, SD 0.9) were included and data of 39 patients were analyzed. Patients in the IG showed strong adherence to the program with a mean of 67 (SD 26.4) training sessions. Maximum work load (P _max) increased in the training group while other fitness indicators did not. Walking distance in the 6MWT improved in both training and waitlist group but not significantly more in trained patients. Similarly, other mobility measures showed no differential group effect. Cognitive functioning remained unchanged. No serious events attributable to the intervention occurred. Conclusion: Although maximum work load improved, 3 months of high-frequency arm ergometry training of low to moderate intensity could not show improved walking ability or cognitive functioning in progressive MS compared to a waitlist CG. The study was registered at www.clinicaltrials.gov (NCT03147105) and funded by the local MS self-help organization.

Keywords: aerobic exercise; arm ergometry; cognition; multiple sclerosis; progressive multiple sclerosis.

Figure 1

Study design: The figure shows the inclusion criteria, the examinations before randomization (T0, Baseline) to either an intervention group (IG) or a control group (CG) and the examination of both groups after 12 weeks (T1). Between T0 and T1, the IG completed a 12-week home-based training. After study completion (T1), patients of the CG were offered the same 12-week home-based training (waitlist).

Figure 2

Arm ergometer (Motomed, Reck). The figure shows the arm ergometer used in the trial.

Figure 3

Flow chart. The figure shows the participant flow chart starting with the assessment for eligibility for participation and through to study completion.

Figure 4

Treatment effects (complete case analyses). Difference in the main outcomes are shown as change from baseline to T1 in the control group (CG, gray) and intervention group (IG, blue). Negative values indicate a decrease from baseline to T1. Change in each group is displayed for the 6-min-walking test (A), in peak oxygen consumption (B), maximum power performed (C) 25-foot-walking-test (D), quality of life measured by the hamburg Quality of Life in MS Questionnaire 10.0 (here, lower scores indicate higher QoL) (E) and the MS-walking-scale-12 (F). Each data point depicts the change of an individual participant from baseline to T1, boxplots represent median and interquartile range. 6 MWT, Six minute walking test; VO₂peak/kg, Peak oxygen consumption; Pmax, maximal Power, T25W, Timed 25-foot walk; HAQUAMS, Hamburger Quality of Life Questionnaire in Multiple Sclerosis; MSWS-12, 12-item MS Walking Scale.