Vascular Parkinsonism: a case of lacunar infarction localized to mesencephalic substantia nigra.

An 80-year-old caucasian man with acute onset parkinsonism is reported here. Lower limbs were predominantly involved and he did not show remarkable improvement with dopaminergic therapy. His MRI investigation showed an isolated lesion on the right side of the mesencephalon, consistent the localization of substantia nigra. The association of acute onset parkinsonism and this radiological finding is very rare in the literature.