OBJECTIVE: To determine the value of investigating the vestibular evoked myogenic potentials (VEMP's) induced by clicks and 500 Hz short tone burst (STB) for the diagnosis of acoustic neuromas. METHODS: We studied the average responses to 100dB clicks and 500 Hz STB in the ipsilateral sternomastoid muscle. Ninety-five healthy subjects and 170 patients suffering from a unilateral acoustic neuroma were included in that study. Caloric and audiometric tests results were also analyzed. RESULTS: Thirty-six/170 patients (21.2%) exhibited normal responses to clicks and to STB whereas 134/170 (78.8%) gave abnormally low or no responses. 78/170 (45.9%) showed no responses to both clicks and STB. In 56/170 patients (32.9%), VEMP's induced by high level clicks and STB were discordant: STB VEMP's were either normal (n=32) or low (n=24) in patients with an abnormal response to clicks (no response n=40 or low response n=16). In contrast, STB-induced VEMP's were always normal in cases of normal responses to clicks. No strong, systematic correlation could be found between saccular nerve dysfunction and either the degree of 4-8 kHz hearing loss or the extent of horizontal canalar impairment. CONCLUSIONS: These data indicate that high level clicks and STB provide complementary information about the functionality of the saccular nerve. Clicks are useful to detect a minor saccular nerve dysfunction. In cases in which there is no response to clicks, STB gives valuable information about a potential residual function of the saccular nerve.
OBJECTIVE: To determine the value of investigating the vestibular evoked myogenic potentials (VEMP's) induced by clicks and 500 Hz short tone burst (STB) for the diagnosis of acoustic neuromas. METHODS: We studied the average responses to 100dB clicks and 500 Hz STB in the ipsilateral sternomastoid muscle. Ninety-five healthy subjects and 170 patients suffering from a unilateral acoustic neuroma were included in that study. Caloric and audiometric tests results were also analyzed. RESULTS: Thirty-six/170 patients (21.2%) exhibited normal responses to clicks and to STB whereas 134/170 (78.8%) gave abnormally low or no responses. 78/170 (45.9%) showed no responses to both clicks and STB. In 56/170 patients (32.9%), VEMP's induced by high level clicks and STB were discordant: STB VEMP's were either normal (n=32) or low (n=24) in patients with an abnormal response to clicks (no response n=40 or low response n=16). In contrast, STB-induced VEMP's were always normal in cases of normal responses to clicks. No strong, systematic correlation could be found between saccular nerve dysfunction and either the degree of 4-8 kHz hearing loss or the extent of horizontal canalar impairment. CONCLUSIONS: These data indicate that high level clicks and STB provide complementary information about the functionality of the saccular nerve. Clicks are useful to detect a minor saccular nerve dysfunction. In cases in which there is no response to clicks, STB gives valuable information about a potential residual function of the saccular nerve.
Authors: Franca Deriu; Enzo Ortu; Saverio Capobianco; Elena Giaconi; Francesco Melis; Elena Aiello; John C Rothwell; Eusebio Tolu Journal: J Physiol Date: 2007-01-18 Impact factor: 5.182
Authors: Vera C Zingler; Eva Weintz; Klaus Jahn; Kai Bötzel; Judith Wagner; Doreen Huppert; Andrea Mike; Thomas Brandt; Michael Strupp Journal: J Neurol Date: 2008-09-26 Impact factor: 4.849