Multiple system atrophy: introduction
The term multiple system atrophy (MSA) was created by Graham and Oppenheimer (1969), as a general label applicable to numerous subtypes of presenile neuronal degeneration, among them olivo-ponto-cerebellar atrophy (OPCA) being one of the better known. After describing the clinicopathological study of a case with orthostatic hypotension and atrophy of multiple neuronal systems, Graham and Oppenheimer implicitly included within MSA Shy–Drager syndrome, striatonigral degeneration, and OPCA, although they were in favor of retaining the eponym Shy–Drager syndrome for cases with MSA and orthostatic hypotension. In this way, credit should be given to the British authors for dividing the anatomical hallmark of primary orthostatic hypotension into two groups: (a) cases in which degeneration of intermediolateral cell columns and autonomous ganglia is part of the MSA pathological framework, as in the early description by Shy and Drager (1960) and (b) cases in which pathological findings are those of idiopathic Parkinson's disease, and therefore the eponym Shy–Drager syndrome is not applicable. Concerning OPCA, it is worth noting that Graham and Oppenheimer did not make any distinction between familial and sporadic forms.
Thus, the concept of MSA emerged, in 1969, not as a new clinicopathological picture but as an all-embracing term of several previously reported syndromes (OPCA, Shy–Drager syndrome and striatonigral degeneration), whose nosology was then well known, though with undoubted overlappings. More recently, Quinn (1989, 1994) reviewed the concept of MSA, proposing that it is not an embracing term but a substitute for other classical eponyms, that are now focused on sporadic OPCA, Shy–Drager syndrome and striatonigral degeneration.