title: The lesion site of vestibular dysfunction in Ramsay Hunt syndrome: a study by click and galvanic VEMP.
abstract: Ramsay Hunt syndrome (RHS) is characterized by vestibulocochlear dysfunction in addition to facial paralysis and auricular vesicles. The present study investigated the lesion site of vestibular dysfunction in a group of 10 RHS patients. Caloric testing, vestibular evoked myogenic potentials by click sound (cVEMP) and by galvanic stimulation (gVEMP) were used to assess the function of the lateral semicircular canal, saccule, and their afferents. The results of caloric testing (all 10 cases showed canal paresis) mean the existence of lesion sites in lateral semicircular canal and/or superior vestibular nerve (SVN). Abnormal cVEMPs in 7 patients mean the existence of lesions in saccule and/or inferior vestibular nerve (IVN). Four of the 6 patients with absent cVEMP also underwent gVEMP. The results of gVEMP (2 absent and 2 normal) mean that the former 2 have lesions of the vestibular nerve, and the latter 2 have only saccular lesions concerning the pathway of VEMPs. Thus, our study suggested that lesion sites of vestibular symptoms in RHS could be in the vestibular nerve and/or labyrinth, and in SVN and/or IVN. In other words, in the light of vestibular symptoms, there is the diversity of lesion sites.
authors.affiliation: Department of Otolaryngology and Head and Neck Surgery, University of Tokyo, Tokyo, Japan.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Ozeki
authors.forename: Shinichi
authors.initials: S
authors.lastname: Iwasaki
authors.forename: Munetaka
authors.initials: M
authors.lastname: Ushio
authors.forename: Naonobu
authors.initials: N
authors.lastname: Takeuchi
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Murofushi
mesh_terms: D000328:Adult; D000368:Aged; D002150:Caloric Tests; D005072:Evoked Potentials, Auditory; D019054:Evoked Potentials, Motor; D005260:Female; D016697:Herpes Zoster Oticus / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007762:Labyrinthitis; D008297:Male; D008875:Middle Aged; D014725:Vestibular Nerve / Q000473:pathology*; D020338:Vestibular Neuronitis / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D014722:Vestibule, Labyrinth / Q000473:pathology* / Q000503:physiopathology