Myasthenia gravis (MG) is a disease where degeneration of the components of the neuromuscular junction results in fluctuating strength and fatigue in skeletal muscles.
We aimed to measure fatigue with the Multidimensional Fatigue Inventory (MFI-20) and identify fatigue associations. Moreover, to measure physical activity (PA), either by self-report or by accelerometry, and to estimate associations of PA and fatigue, taking relevant factors into consideration. Finally, to measure gait parameters in patients with neuromuscular diseases and explore if rhythmic auditory stimulation (RAS) influence the 6-min walk test (6MWT).
Patients were recruited from the Danish National Registry of Patients (DNRP) or the Copenhagen Neuromuscular Center from 2014 to 2020.
Fatigue scores were high, especially in physical and general fatigue, and related to severe MG, insomnia, comorbidity, overweight, and living alone. Around 50% reported inactivity, which was related to fatigue. Moreover, severe MG and age were associated with sedentary behavior and less time spent on PA. One-third of the patients reported dissatisfaction with their symptom state. Factors related to dissatisfaction were severe MG and fatigue, depression, low quality of life, and short disease duration. The 6MWT measured fatiguability, and RAS increased walking distance without additional exertion than standard 6MWT.