Results of rehabilitation of myasthenia gravis patients with subclinical respiratory disturbances

Background. The main cause of morbidity and mortality in myasthenia gravis (MG) patients is respiratory failure that is based on subclinical respiratory disorders. Rehabilitation opportunities for such patients are limited by the frequent presence of a subjective feeling of fatigue that is important to distinguish from the main symptom of the disease – pathological muscle fatigability. This is determined by the need to achieve a balance between the obvious benefits of physical activity on the one hand and the rapid increase in fatigue and fatigability on the other and the peculiarities of the selection of physical exercises.

Aim. To analyze the effectiveness of rehabilitation of MG patients with subclinical respiratory disturbances, to determine the level of fatigue in MG, to assess the effect of physical activity on fatigue.

Materials and methods. The fatigue was studied in 53 MG patients using visual analog scale, “Well-being, activity, mood” questionnaire and fatigue assessment scale. Those who had no therapy enhancement within 6 months before the start as well as during the entire rehabilitation period were included in the study to determine the net effect of rehabilitation. The external respiration function was studied before and after the rehabilitation course. Before conducting the study a sample size planning method was used for independed and depended groups. Based on the results of the calculations a group of 22 patients with generalized MG without signs of respiratory disorders was formed to study the possibilities of rehabilitation.

Results. According to the questionnaire a significant increase in the level (U, p = 0.002) and frequency of fatigue (χ2, p = 0.002), frequent poor health (χ2, p = 0.041 according to visual analog scale and χ2, p <0.0001 according to “Well-being, activity, mood” questionnaire), increased physical fatigue (U, p = 0.005) were showed. The negative effect of fatigue on well-being (rs = –0.78; p <0.05) and activity (rs = –0.73; p <0.05) was established. As a result of rehabilitation of MG patients with subclinical respiratory disorders a significant increase of vital capacity (W, p = 0.026) and inspiratory reserve volume (W, p = 0.044) were achieved.

Good tolerance and absence of negative effects of physical exercise on general well-being (W, p = 0.495) on visual analog scale have been established. There was no deterioration on “Well-being, activity, mood” questionnaire: well-being (W, p = 0.467), activity (W, p = 0.396) and mood (W, p = 0.709). There was no increase in physical fatigue (W, p = 0.368) on fatigue assessment scale.

Conclusion. Taking into account the pronounced effect of fatigue on the MG patient’s condition physical rehabilitation should be selected individually, preventing an increase in fatigue, muscle fatigability and weakness. Soft, mild or moderate intensity exercises are well tolerated and have no side effects.