Classification and clinical features of motor neurone diseases and motor neuropathies in adults.

The term motor neurone disease encompasses combined upper and lower motor neurone disorders (amyotrophic lateral sclerosis), pure lower motor neurone disorders (spinal muscular atrophies, multifocal motor neuropathies, post irradiation lumbosacral radiculopathy, post-polio syndrome, hereditary bulbar palsy) and pure upper motor neurone disorders (primary lateral sclerosis, hereditary spastic paraplegia, neurolathyrism, Konzo). The chief clinical and electrophysiological criteria for these different disorders are discussed, with particular attention to diagnostically distinctive characteristics of each. Age of onset, and inheritance are considered as additional diagnostic features.