Reversible bilateral internuclear ophthalmoplegia due to head trauma: a case report.

This case report concerns a patient who developed reversible bilateral internuclear ophthalmoplegia as an immediate consequence of head trauma. To our knowledge, only one case of internuclear ophthalmoplegia related to head trauma has been previously reported in the literature. The mechanism by which trauma can produce a relatively isolated brain stem lesion to the medial longitudinal fasciculus is unclear. Some experimental data on the mechanisms of cerebral concussion would indicate that the biomechanical forces due to impact acceleration of the head exert their predominant effect on the posterior portion of the brain stem. This might account for critical vulnerability of the structures situated in this portion, including the medial longitudinal fasciculus.