Vestibular evoked myogenic potentials in the sternomastoid muscle are not of lateral canal origin.

We studied vestibular evoked myogenic potentials in 6 patients after unilateral vestibular neurectomy and in 22 patients after unilateral vestibular neuritis and unilateral absent caloric responses. We found that the ipsilesional vestibular evoked potentials were abolished in every patient after unilateral vestibular neurectomy. In vestibular neuritis patients we found that the ipsilesional vestibular evoked potentials were absent in some but not in all cases. These findings confirm that the p13-n23 potential is of vestibular origin and also show that it is not of lateral canal origin.