Multiple System Atrophy

Four features are present in idiopathic Parkinson's disease: slowing of movement (bradykinesia), tremor, muscle rigidity, and a tendency to fall. The four together mean that Parkinson's disease can be diagnosed. When three or fewer are present, the combination is referred to as parkinsonism.

Parkinsonism occurs, to some degree, in the majority of patients with multiple system atrophy. This is more prominent in striatonigral degeneration type of multiple system atrophy. Slowing of movement (bradykinesia) and rigidity are more common, while tremor, which is more common in idiopathic Parkinson's disease, is less prominent in multiple system atrophy. Furthermore, like idiopathic Parkinson's disease, these patients also display gait disturbance, which is independent of ataxia. In contrast to idiopathic Parkinson's disease, the parkinsonian symptoms in these patients respond poorly to dopaminergic agents.