[MSA update]. 
Multiple system atrophy (MSA) is a sporadic neurodegenerative disorder characterized by various combinations of parkinsonism, cerebellar ataxia and autonomic failure.  Although the clinical entities of olivopontocerebellar atarophy (OPCA), striatonigral degneratin (SND) and Shy-Drager syndrome have been conventionally used, recent identification of oligodendroglial cytoplasmic inclusions (GCIs) as the pathognomonic findings has established the clinicopathological entity of MSA.  Epidemiological studies in Japan have shown that MSA is the most common form of sporadic ataxia.  Among the various clinical forms of MSA, OPCA has been shown to be the most common form.  Although MSA has been regarded as a sporadic disease, familial occurrence has recently been identified.  Integrated analyses of non-parametric linkage analyses on the familial MSA cases and association studies on sporadic MSA cases are expected to accelerate the studies on identification of genes involved in the pathogenesis of MSA.