Nigral involvement in atypical parkinsonisms: evidence from a pilot study with ultra-high field MRI.

Ten healthy subjects (HS) and 15 patients with atypical parkinsonisms underwent 7-T susceptibility-weighted-imaging MR to evaluate substantia nigra (SN). All HS were judged "normal". Twelve out of 15 patients exhibited bilateral abnormal SN while three patients with corticobasal degeneration (CBD) showed bilateral normal aspect of SN. Anatomical changes of SN at 7 T occur in multiple system atrophy and progressive supranuclear palsy as previously reported in Parkinson's disease. Preserved SN in CBD confirms the pathological heterogeneity of this disease.