Long-Term Respiratory Muscle Endurance Training in Patients with Myasthenia Gravis: First Results after Four Months of Training

Beate Rassler,Petra Kalischewski,Irene Baumann,Stephanie Hallebach,Grit Marx

doi:10.4061/2011/808607

Abstract

Myasthenia gravis (MG) is characterized by reduced muscle endurance and is often accompanied by respiratory complications. Improvement of respiratory function is therefore an important objective in MG therapy. A previous study demonstrated that respiratory muscle endurance training (RMET) over four weeks increased respiratory muscle endurance of MG patients to about 200% of baseline. The purpose of the present study was to establish an appropriate maintenance training and to test its effects over four months. Ten patients with mild to moderate MG participated in this study. During the first month, they performed five training sessions per week. For the following 3 months, training frequency was reduced to five sessions per two weeks. Myasthenia score, lung function, and respiratory endurance were determined prior to training, after the first month, and after 4 months. Myasthenia score improved from 0.71 ± 0.1 to 0.56 ± 0.1 (P = 0.007). Respiratory endurance time increased from 6.1 ± 0.8 to 20.3 ± 3.0 min (P < 0.001). In conclusion, this RMET maintenance program is feasible and is significantly beneficial for MG patients.

Highlights

Myasthenia gravis (MG) is an autoimmune disease characterized by blockade of the neuromuscular synapse
The patients involved in this study were regularly consulting two neurologists specialized in MG who were involved in this study (IB, PK)
We evaluated Besinger score, vital capacity (VC), forced expiratory volume in 1 s (FEV1), peak expiratory flow (PEF), maximal voluntary ventilation (MVV), PImax, TLim, and VLim

Summary

Introduction

Myasthenia gravis (MG) is an autoimmune disease characterized by blockade of the neuromuscular synapse. Muscle strength and, endurance are reduced, ensuing in increased muscular fatigue [1, 2]. In most MG patients, the entire muscular system is concerned, and this may involve respiratory muscles. Patients with generalized MG often present a characteristic “myasthenic pattern” with decreasing respiratory volumes during MVV [3] and reduced respiratory muscle endurance [2]. Respiratory muscle dysfunction can further deteriorate patients’ physical fitness and evoke upper airway obstruction [4], sleep apnea [5, 6], or even respiratory failure as the characteristic feature of myasthenic crisis [7, 8]. Improvement of respiratory muscle function is an important objective in MG therapy

Objectives

Methods

Results

Conclusion