Childhood-onset neuromuscular and neurological disorders (NMD) are a diverse group of rare conditions in which muscle function is significantly impaired. Due to progress in NMD management over recent decades, particularly the use of non-invasive ventilation (NIV) to treat chronic respiratory failure, many individuals are surviving into adulthood and even middle age. However, older individuals are developing potentially fatal complications related to the heart e.g. sudden cardiac death, gastrointestinal (GI) tract and increasing dependence on NIV.~Previous studies largely in children and adolescents suggest individuals with NMD may develop problems of the autonomic nervous system (ANS), a network of nerves vital to controlling the body's short-term responses to internal and external stimuli. It is likely some complications of NMD are related to ANS abnormalities.~This will be an exploratory observational study using a cross-sectional design in which non-invasive tools will be used to evaluate autonomic function during wake and sleep. Individuals over 16 years of age with a confirmed NMD diagnosis will be recruited. Derived parameters of autonomic function including heart rate variability will be compared to values from an exploratory reference group of age- and sex-matched healthy adults. Autonomic function will also be correlated to measures of symptom burden, complications, quality of life and disease severity. Qualitative methods will be used to further evaluate the experience and perceptions of adults with NMD in making decisions about their personal and medical care, which become more complex with increasing age and disease severity.
This exploratory observational study evaluates autonomic function using measures including heart rate variability in adults with childhood-onset neuromuscular and neurological disorders (NMD) who use non-invasive ventilation (NIV) as part of their long-term care. Autonomic function will be correlated with measures of symptom burden, disease severity and complications.