[Bilateral paresis of the superior oblique muscle caused by hematoma of the mesencephalic tegmentum].

Primary hematomas of the brain stem are rare. We report the case of a small spontaneous mesencephalic hematoma which occurred in a 50 year-old normotensive male patient. The hematoma produced paresis of the superior oblique muscle and a lesion of the left spinothalamic tract. The outcome was favourable.