Reason: new onset left sided rigidity, concern for ischemic event versus MSA versus atypical parkinson's disease: left sided weakness and bradykinesia, looking for hummingbird sign in brainstem. There is punctate susceptibility effect in the right globus pallidus, but the rest of the basal ganglia are unremarkable. The brainstem is intact, without evidence of the hummingbird or Mickey mouse sign. The brain parenchyma and cerebellum also appear unremarkable, aside from minimal nonspecific cerebral white matter T2 hyperintensity. There is no evidence of intracranial mass or acute infarct. There is no abnormal intracranial enhancement. The ventricles and basal cisterns are normal in size and configuration. There is no midline shift or herniation. The major cerebral flow voids are intact. The orbits, skull, paranasal sinuses, and scalp soft tissues are grossly unremarkable.
1. Nonspecific punctate susceptibility effect in the right globus pallidus, which may represent incipient mineralization. Otherwise, no specific imaging findings for progressive supranuclear palsy or multiple system atrophy. Perhaps a nuclear medicine scan may be useful for further evaluation.2. No evidence of intracranial mass or acute infarct. 