Acute comitant esotropia in a boy with head trauma and convulsions receiving carbamazepine.

We examined an 11-year-old boy who complained of acute onset of diplopia. The patient had head trauma and postsurgical convulsions and had been treated with carbamazepine. Diplopia developed after the dose of carbamazepine was increased to 700 mg/day. On examination, comitant esotropia and lateral gaze nystagmus were found. These disorders disappeared after carbamazepine was decreased to 400 mg/day. We believe that acute comitant esotropia and lateral gaze nystagmus may have been precipitated by head trauma and carbamazepine in our patient.