Severely disabled multiple sclerosis patients can achieve the performance of healthy subjects after expiratory muscle strength training.

Abstract

BACKGROUND\nThe efficacy of expiratory muscle strength training (EMST) in patients with multiple sclerosis (MS) is controversial. The current study s primary objective was to test the effects of a progressive and intensive 12 week home based EMST program on expiratory muscle strength and voluntary cough strength. The secondary objective was to determine the retention of EMST benefits.\n\n\nMETHODS\nThirty-five severely disabled MS patients (relapsing-remitting MS, n = 15; primary progressive MS, n = 5; secondary progressive MS, n = 15)\xa0with Expanded Disability Status Scale (EDSS) 5.0 - 7.0 were included in the study. Within 36 weeks, patients completed 12 weeks of a non-training period, 12 weeks of EMST and 12 weeks of a detraining period. Maximal expiratory pressure (PEmax) and voluntary peak cough flow (vPCF) were assessed 4 times: at week 0 (baseline), week 12 (pre-training), week 24 (post-training), and week 36 (post-detraining). MS patients included in the study were compared to age- and sex-matched healthy subjects. In the healthy controls, the PEmax and vPCF were assessed once to obtain normative data.\n\n\nRESULTS\nTwenty-six patients completed the training period (mean age 52.7 ± 10.2, EDSS 5.9 ± 0.6) and were compared to 26 sex- and age-matched healthy subjects (mean age 53.5 ± 5.8). Patients with MS had a lower PEmax (p = 0.002) and vPCF (p = 0.022) at baseline than the healthy control group. In training period, the PEmax and vPCF increased (p = 0.0000; effect size: d = 0.94 and p = 0.0036; d = 0.57 respectively) in comparison with the non-training period (p = 0.0692; d = -0.36 and p = 0.5810; d = 0.11 respectively). Following the 12 weeks detraining period, the PEmax and vPCF declined but remained 16.7% and 5.5% respectively above the pre-training values. No differences were observed in the PEmax and vPCF between the MS group at the post-training and post-detraining timepoint and the healthy control group normative values.\n\n\nCONCLUSIONS\nEMST improves expiratory muscle strength and voluntary cough strength in severely disabled MS patients.