[Vestibular evoked muscle potentials dependency on neural origin and the location of an acoustic neuroma].
BACKGROUND
Most acoustic neuromas (AN) originate from the inferior vestibular nerve (IVN). Vestibular evoked myogenic potentials (VEMP) are accepted as the only unilateral test for the function of the sacculus and the IVN.


METHODS
The influence of the origin from the IVN and superior vestibular nerve (SVN), and the position of the AN in relation to the internal auditory canal on VEMPs was investigated. A total of 39 patients (aged: 30-67 years, mean: 53 years) were examined. The VEMPs were recorded on the activated sternocleidomastoid muscle and averaged over 200 stimuli. Tone bursts (95 dB nHL; 500 Hz; stimulation rate 5 Hz) were used to generate the VEMPs.


RESULTS
The exact origin of the AN from the SVN or the IVN could be determined intraoperatively and correlated using VEMP in 28 patients.


CONCLUSIONS
The origin of the AN has only a marginal influence on the results of VEMP measurements. The position of the AN in relation to the internal auditory canal seems to have more influence than the origin.
Hamann
C
C
Klinik für Hals-Nasen-Ohren-Heilkunde des Universitätsklinikums Magdeburg. hamann73@yahoo.de
Rudolf
J
J
von Specht
H
H
Freigang
B
B
D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D000368:Aged; D005072:Evoked Potentials, Auditory; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014724:Vestibular Function Tests / Q000379:methods*; D000160:Vestibulocochlear Nerve Diseases / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology