Brainstem auditory evoked potential (BAEP) abnormalities in subjects with craniovertebral malformations.

We report the data on 42 monaural BAEP recordings from 10 patients with craniovertebral malformations. Of 8 preoperative recordings from 3 patients 6 showed an increased I-III interpeak latency (IPL). Of 28 recordings taken shortly (1-12 months) after surgery 21 showed an abnormal I-III IPL. On the other hand, of 6 recordings from 3 patients 20 years after surgery 5 were in the normal range and 1 showed an abnormal I-III IPL. Although the most important site of craniovertebral malformations is the cervicomedullary junction, the results reported suggest unilateral or asymmetrical bilateral involvement of the medullary-pontine junction, on the evidence of BAEP wave III, in a large proportion of patients with these malformations.