Hyperexcitable state of the brainstem in children with post-traumatic vomiting as evidenced by brainstem auditory-evoked potentials.

Brainstem auditory-evoked potentials were studied within 6 hours after mild head injury in 17 children with post-traumatic vomiting. Compared with 8 control subjects, the children with frequent vomiting showed a significant shortening of peak latency for wave III. This mechanism appears to be essentially the reverse of that found in the post-concussion syndrome in which significant delay of wave III has been reported. These findings indicate transient facilitatory effects of trauma on brainstem auditory transmission in post-traumatic vomiting.