Sleep Related Conditions with Myasthenia Gravis: Evidence, Causes and Implications

Abstract

Myasthenia gravis (MG) is an autoimmune disease caused mainly by antibodies against skeletal muscle nicotinic acetylcholine receptors (nAChRs) at the postsynaptic membrane resulting in depletion of acetylcholine at the neuromuscular junction (NMJ). Muscle fatigue is the cardinal symptom of MG. Respiratory muscle weakness and breathing problems are manifestations of MG even in mild stages of the disease resulting in significant morbidity and mortality. Also sleep related conditions are among the manifestations of MG which include sleep disordered breathing (SDB) [i.e. central (CSA) and obstructive (OSA) sleep apneas, hypoventilation or hypoxemic syndromes], reduced sleep efficiency and quality, increased number of nocturnal awakenings, excessive daytime sleepiness, reduced rapid eye movement sleep and altered sleep perception and dreaming. On the other hand, sleep abnormalities may result in lack of concentration, cognitive impairments and mood disturbances as depression and anxiety. Central and peripheral mechanisms have been suggested for the association between MG and central nervous system manifestations and sleep abnormalities. Neurologists and sleep medicine professionals should be aware of the associations between OSA/CSA, hypoventilation and other sleep related conditions with MG and consider systematic investigations including polysomnography and ventilatory support. This will reduce morbidity and mortality and improve quality of lives of patients with MG.