Affiliations: [a] Department of Audiology, Karolinska Hospital, Stockholm, Sweden | [b] Department of Neurosurgery, Karolinska Hospital, Stockholm, Sweden
Correspondence:
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Corresponding author: Krister Brantberg, MD, Department of Audiology, Karolinska Hospital, S-171 76 Stockholm, Sweden. Tel.: +46 8 51775907; Fax: +46 8 51774041; E-mail: krister.brantberg@ks.se
Abstract: Sound and skull-tap induced vestibular evoked myogenic potentials (VEMP) were studied in a 43-year-old man following inferior vestibular neurectomy. Surgery was performed because of a small acoustic neuroma. Postoperative caloric testing suggested sparing of superior vestibular nerve function on the operated side. In response to sound stimulation there were no VEMP on the operated side, irrespective of whether sounds were presented by air- or bone-conduction. This suggests sound-induced VEMP to be critically dependent on inferior vestibular nerve function and this is in agreement with present knowledge. However, VEMP were obtained in response to forehead skull taps, i.e. positive-negative VEMP not only on the healthy side but also on the operated side. This suggests remnant vestibular function on the operated side of importance for forehead skull tap VEMP, because with complete unilateral vestibular loss there are no (positive-negative) VEMP on the lesioned side. Thus, forehead skull-tap VEMP depend, at least partly, on the superior vestibular nerve function.
