Midbrain hemorrhage presenting with oculomotor nerve palsy: case report

Abstract

BACKGROUND We report a case of isolated oculomotor nerve palsy caused by a midbrain hemorrhage. CASE DESCRIPTION A 75-year-old man visited our hospital complaining of double vision and left eye ptosis without headache. Neuro-ophthalmic examination showed that his left and right pupils were 3.5 mm and 3 mm in diameter, respectively, that left downward eye movement was limited, and that convergence of the right eye was limited. Magnetic resonance imaging (MRI) demonstrated that there was a hematoma located in the anterior tegmentum of the left midbrain. Two weeks after admission and treatment, including conservative therapy, his double vision gradually disappeared. CONCLUSION To date, 73 cases have been reported in the literature. Most cases of isolated oculomotor nerve palsy have been caused by diabetes mellitus, aneurysm, or infarction. However, focal midbrain hemorrhage incidentally produces third nerve palsy. MRI is extremely helpful in diagnosing a small hemorrhage of the midbrain in such cases.