[Primary oculomotor nerve palsy due to head injury: analysis of 10 cases]

Ten cases of primary oculomotor nerve palsy due to head injury are presented. All ten patients had a dilated, non reactive pupil. Seven had complete oculomotor palsy. Two had partial extraocular palsy or blepharoptosis and one had neither extraocular palsy nor blepharoptosis. The initial ophthalmoplegia was recognized immediately after trauma. Nine patients had severely impaired consciousness on admission, but eight patients recovered fully within two months after the traumatic event, while one patient remained disoriented. Emergency CT scan on admission showed mass lesions in no patients except one who had a hematoma measuring 3 cm in the frontal lobe, but had no herniation sign. Patients with complete oculomotor palsy had a high incidence of traumatic SAH (71%) or skull fracture (57%). Recovery from third nerve palsy was not so good. The follow-up period extended from 3 months to 18 months. Of the 10 patients, none recovered completely from third nerve palsy. The prognoses of blepharoptosis, external ophthalmoplegia and internal ophthalmoplegia were analyzed separately. The recovery rates were 78%, 44% and 20%, respectively, the internal ophthalmoplegia showing poorest recovery. We discuss the mechanism of direct injury to the oculomotor nerve.