Mesencephalic hemorrhage and third nerve palsy.

We report the clinical and computed tomography findings in two patients with small mesencephalic hematomas. Both patients presented with unilateral oculomotor paralysis and minor associated neurological symptoms. One patient had pupillary involvement suggestive of a peripheral third nerve lesion. Computed tomography evaluation disclosed small unilateral anterior mesencephalic hematomas involving the oculomotor fascicle. Angiography in both cases and surgery in the first case disclosed no evidence of an arteriovenous malformation or neoplasm. Both patients showed significant clinical improvement within 3 months.