Motor neuron diseases: Amyotrophic lateral sclerosis and spinal muscular atrophy

Motor neurons are divided into upper motor neurons and lower motor neurons.Upper motor neurons transmit signals produced in the brain to the lower motor neurons.Lower motor neurons transmit these signals to the muscles of respective regions of the body to initiate motion.Injury to these motor neurons mainly result in motor neuron diseases, which may cause serious complications and death.This review discusses the definition, epidemiology, etiology, clinical symptoms, diagnosis, and treatment methods of the motor neuron diseases of amyotrophic lateral sclerosis and spinal muscular atrophy.