The mean age of onset is 54. The Parkinsonism of MSA is generally an akinetic rigid syndrome, similar to that of PSP . Rest tremor may occur but is not a predominant feature.
Postural instability is common.
The mean survival is roughly 6 years. There is neuronal loss and gliosis in the inferior olives, pons, cerebellum, substantia nigra, locus ceruleus, striatum and the intermediolateral column of the spinal cord. Typical but not specific to MSA are argyrophilic inclusions containing accumulations of tubules. Alpha-synuclein has recently been shown to be accumulated in glial cytoplasmic incusions. Depletion of catecholamine neurons in the rostral ventrolateral medulla is a consistant finding in patients with MSA and autonomic failure.