Partial dorsal mesencephalic hemorrhages: report of three cases.

We studied three patients with spontaneous dorsal mesencephalic hemorrhages. One patient had Parinaud's syndrome with a unilateral hemorrhage confined to the rostral tectal plate. The second patient had vertical gaze palsy, skew deviation, and bilateral Horner's syndrome due to a unilateral hemorrhage that involved the superior colliculus and extended anteriorly into the midbrain tegmentum and inferiorly to the rostral dorsal pons. The third patient had a hemorrhage in the caudal tectal plate, with bilateral fourth cranial nerve palsies, unilateral Horner's syndrome, and ataxia. There was hydrocephalus due to obstruction of the aqueduct in two patients. The patients recovered, but with some degree of disability.