Early auditory evoked potentials (EAEPs) in the rabbit. Normative data and effects of lesions in the cerebello-pontine angle.

Early auditory evoked potentials (EAEPs) were measured in rabbits. After establishing normative data an operative method was developed to expose the cerebello-pontine angle. Compression of the VIIIth nerve and a reduction of blood supply to the cochlea via the labyrinthine artery altered the EAEP systematically. In all cases of an VIIIth nerve lesion wave 1 continued to be elicited whereas waves 2-5 disappeared. Circulatory disturbances had an effect upon wave 1. The results indicate that the generator of wave 1 is the unit cochlea/acoustic nerve and of waves 2-5 the auditory pathway within the brain stem. The resultant data help to understand wave alterations in patients with acoustic neuromas.