Multiple system atrophy--the nature of the beast.

Multiple system atrophy (MSA) is generally considered a rare disease, but may account for up to 10% of patients with Parkinsonism. The profusion of names for this disease, which may present to general physicians, psychiatrists, cardiologists, autonomic specialists, general neurologists and those with a special interest in Parkinsonism (this author's own perspective) or cerebellar disorders, together with ignorance of its protean manifestations, may account for its underrecognition and misdiagnosis. In this article, the history and nosology of the condition are considered, and provisional diagnostic criteria are advanced. The usefulness (or otherwise) of ancillary investigations is addressed, and the shortcomings of current methods of treatment are stressed. As with idiopathic Parkinson's disease, the ultimate goal of eradicating the disease entails better diagnosis in order to establish the cause, and thence to develop a radical treatment capable of preventing or arresting the disease process.