The topic multiple-system atrophy (MSA) alerts the reader that a description of a neurodegenerative disorder characterized by predominant involvement of the basal ganglia, cerebellar, and autonomic pathways follows. The uninitiated may be understandably misled by the broad inference of the term MSA. We describe the historical derivation of this appellation, although perhaps we should not dismiss the impulse to reexamine the congruity of this diagnostic subset with the range of patients seen in the clinical setting. The sharp distinction of MSA from the other neurodegenerative processes, as depicted in discrete chapters of this book, belies the challenge facing the clinician when diagnosing the individual patient. Despite the prodigious advances in medicine, MSA and neurodegenerative disorders as a group remain clinical diagnoses, and the heterogeneity of our patients defies simple classification.
The conceptualization of the diagnosis of MSA emerged from a series of publications that each described fragments of a larger picture. Dejerine and Thomas1 first coined the term olivopontocerebellar atrophy (OPCA) in 1900 to describe two sporadic cases of progressive cerebellar degeneration with parkinsonism. Sixty years later, Shy and Drager2 published the first clinicopathological study of a patient with idiopathic orthostatic hypotension (OH). They recognized the association of OH with a primary degenerative disorder of the nervous system involving the intermediolateral cell column of the spinal cord, medulla, pons, midbrain, cerebellum, and basal ganglia. The full clinical syndrome comprised “orthostatic hypotension, urinary and rectal incontinence, loss of sweating, iris atrophy, external ocular palsies, rigidity, tremor, loss of associated movement, impotence, the findings of an atonic bladder and loss of the rectal sphincter tone, fasciculations, wasting of distal muscles, and evidence of a neuropathic lesion.”2
Also in 1960, van der Eecken et al.3 described a unique pathological subgroup among a large number of patients with paralysis agitans. Striatopallidonigral degeneration was identified with “virtual disappearance of the small cells of the caudate nucleus and putamen” in a few patients with rigidity but minimal tremor. The full clinicopathological study was published the following year.4 In addition to parkinsonism, brisk reflexes, extensor plantar responses, ataxia, dysarthria, syncope, incontinence, and impotence were described among the three patients reported. Neurodegeneration was also identified in the cerebellum, olivary nuclei, and pons.
The conceptual threads of the three disorders, OPCA, Shy–Drager syndrome (SDS), and striatonigral degeneration (SND), were tied together in a seminal paper by Graham and Oppenheimer5 in 1969:
What is needed is a general term to cover this collection of overlapping progressive presenile multisystem degenerations. As the causes of this group of conditions are still unknown, such a general term would merely be a temporary practical convenience… What we wish to avoid is the multiplication of names for ‘disease entities’ which in fact are merely the expressions of neuronal atrophy in a variety of overlapping combinations. We therefore propose to use the term multiple system atrophy to cover the whole group.