The application of vestibular-evoked myogenic potentials in otoneurosurgery.

Abstract

To evaluate the applicability of vestibular-evoked myogenic potentials (VEMPs) in the diagnostics, intraoperative monitoring, and postoperative follow-up of patients in otoneurosurgery. A prospective study of patients who underwent either cochlear implantation (CI, n = 18) or were diagnosed with an acoustic neuroma (AN, n = 9) or with neuro(micro)vascular compression of the VIIIth nerve (NVC, n = 27) in the period 2002 to 2004. The follow-up was 1 year for all patients. A tertiary-referral unit. VEMPs could be recorded in 64% of all patients before CI and in 22% after surgery. The patients with AN had normal VEMPs in 22% of all cases when first diagnosed. Normal VEMPs were found in 37% of those patients with NVC. From the 5 AN patients who had to be operated, only 1 had intact VEMPs after surgery. In contrast, after microvascular decompression all patients (4) had normal VEMPs. VEMPs are helpful in diagnosing patients with vertigo to better identify saccular defects. They are highly sensitive in the early diagnosis of retrocochlear lesions. VEMPs can help to reliably identify patients with a retrocochlerar lesion at an early stage and can be used in intraoperative, neurophysiological monitoring. C-4.