Multiple system atrophy (MSA) is a degenerative central nervous system disease of unclear origin. Patients affected typically show symptoms attributable to the combined involvement of the extrapyramidal, pyramidal, cerebellar and autonomic nervous systems. At onset patients mostly see a doctor because of extrapyramidal or--more rarely--cerebellar symptoms. Evidence of autonomic nervous system involvement is often not apparent, at least to the neurologist, before the history is taken. In later stages, by contrast, involvement of all of the above systems is clinically detectable.