Neonatal presentations of neuromuscular disorders

The term 'neuromuscular diseases' defines disorders of the extended motor unit. Newborns with disorders of peripheral nervous system (PNS) (motor neurons, nerve roots, plexuses, peripheral nerves, neuromuscular junction, and skeletal muscles) present most frequently with hypotonia, weakness, contractures, respiratory and feeding difficulties. Challenge in the newborn period is, hypotonia may also occur with more common central causes such as; electrolyte disturbances, sepsis, hypoxic-ischemic encephalopathy (HIE), congestive heart failure, and inborn errors of metabolism. Moreover, newborns with PNS involvement and/or genetic neuromuscular disorders (NMD) can also be prone to intrapartum asphyxia which further masks an underlying condition. This is why, NMD is also described as one of the 'HIE-mimics'. Genetic counseling, individualized treatment strategies, standards of care require accurate diagnosis. Neuromuscular field is moving to screening programs and pre-symptomatic diagnosis with promising disease-modifying treatments. The aim of this paper is to discuss approach to NMD within the newborn period in line with clinical history, examination findings, and diagnostic tests.