[A patient with multiple system atrophy presenting prolonged levodopa-responsive parkinsonism and off-dystonia of the trunk].

A 46-year-old man had a 7-year history of dopa-responsive parkinsonism. Four years after starting levodopa, he had typical motor complications such as wearing-off and peak dose as well as off-period dystonia of his trunk. Brain MRI showed marked atrophy of the brainstem and cerebellum, and the cross sign was present in the pontine base. There was neither abnormal signal intensity nor atrophy in the basal ganglia. Then, he was suspected as having multiple system atrophy (MSA). It is not easy to differentiate MSA from Parkinson diseases, particularly when the patient shows good response to levodopa and motor complications like those seen in Parkinson's disease. If the striatal pathology was not severe and nigral degeneration was prominent, presynaptic parkinsonism might occur in MSA, and putaminal preservation might account for good response to levodopa therapy. In patients with MSA, disproportionate antecollis is common before levodopa treatment, and levodopa induced off-dystonia of his trunk is very rare.