Clinicopathologic correlation in a case of pupillary dilation from cerebral hemorrhage.

A patient who developed pupillary dilation on the side of a large cerebral hemorrhage underwent serial examinations, computed tomography, and magnetic resonance imaging. Autopsy dissection was performed to allow in situ examination of the structures near the third nerves and tentorial edge. The origin of the oculomotor nerve was displaced medially, causing the distal nerve to "kink" over the clivus just posterior to the clinoid. Transtentorial herniation of the medial temporal lobe did not appear to play a role in third-nerve compression.