Motor neuron disease

Motor neuron diseases or motor neurone diseases (MNDs) are a group of rare neurodegenerative disorders that selectively affect motor neurons, the cells which control voluntary muscles of the body. They include amyotrophic lateral sclerosis (ALS), progressive bulbar palsy (PBP), pseudobulbar palsy, progressive muscular atrophy (PMA), primary lateral sclerosis (PLS), and monomelic amyotrophy (MMA), as well as some rarer variants resembling ALS. Motor neuron diseases affect both children and adults. [Source: Wikipedia ]