Isolated or predominant ocular motor nerve palsy as a manifestation of brain stem stroke

There have been few reports of strokes producing isolated or predominant ocular motor nerve palsies as a clinical manifestation.

We studied seven patients with brain stem stroke who had ocular motor palsies as the only or the predominant neurological manifestation, and we correlated their clinical features with radiological findings.

Five patients had small strokes in the area of oculomotor nuclei or fascicles and showed various combinations of oculomotor disturbances. Three of these patients showed vertical gaze paresis of the opposite eye. One patient with a small hemorrhage near the aqueduct of Sylvius showed fourth nerve palsy on the contralateral side, and a patient with a small infarct in the pontine tegmentum showed isolated sixth nerve palsy. Nonocular minor neurological signs included trigeminal sensory changes in four patients and clumsy arm in two. Ocular and nonocular dysfunctions generally improved within several months. Radiological findings of the brain stem correlated well with the ocular signs.

We conclude that acute brain stem stroke should be included in the differential diagnosis of isolated ocular motor nerve palsies and that appropriate diagnostic investigations should be performed in these cases.