Localization of Claude's syndrome.

Although the red nucleus often has been suggested to be the lesion site responsible for Claude's syndrome, the precise localization of the syndrome is uncertain. Lesion sites were reviewed in six patients with Claude's syndrome and compared with other patients with the syndrome identified by a literature search. The findings strongly suggest that Claude's syndrome occurs because of a lesion of the superior cerebellar peduncle just below and medial to the red nucleus. Midbrain infarction and partial oculomotor nerve palsy was common.