[Claude syndrome caused by mesencephalic infarction: 2 cases].

Paramedian midbrain infarcts limited to the oculomotor nerve fibers are uncommon. We studied 2 cases where the clinical syndrome included a third cranial nerve palsy and a contralateral cerebellar ataxia. The CT scan disclosed a paramedian midbrain tegmental infarct, so that it is possible to term our two cases Claude's syndrome. The oculomotor nerve fascicular palsies were complete in one case and limited to the extraocular muscles in the second case. The selective involvement of oculomotor function suggests intraaxial fascicular organisation of the third cranial nerve in the brainstem.