The vestibular evoked myogenic potential: a test-retest reliability study.
OBJECTIVE
The purpose of this study was to evaluate the reliability of the vestibular evoked myogenic potential (VEMP) response in a clinical setting when only a feedback mechanism is available for monitoring background EMG.


METHODS
Sixty-one healthy subjects participated in the investigation of the within-session reliability, whereas fourteen of them were retested after one week for examination of the between-session reliability. VEMPs were recorded using 500 Hz tone bursts with the subjects in a sitting position and their heads turned away from the test ear to the contralateral shoulder, thereby pushing their chin against the inflatable cuff of a blood pressure manometer, serving as feedback method.


RESULTS
The feedback method revealed latency and amplitude values comparable to other data in the literature where different test conditions were applied. Excellent reliability with ICC values ranging from 0.78 to 0.96 and CV(ME) values ranging from 4% to 36%, was achieved for P1 and N1 latency, threshold and interpeak amplitude. Good reliability with ICC values of 0.65 and 0.68 and CV(ME) values of 170% and 189%, was obtained for the asymmetry ratio.


CONCLUSIONS
A unilateral muscle contraction controlled by a feedback mechanism resulted in reliable response parameters, comparable right to left and corresponding to literature data obtained in different test conditions.


CONCLUSIONS
The use of a blood pressure manometer as feedback mechanism combined with a meticulously controlled positioning of the head and contraction of the SCM muscle provides a reliable alternative in clinical settings, when the background muscle contraction cannot be measured or software related correction algorithms are not accessible.
Maes
Leen
L
Ghent University, Faculty of Medicine, ENT-Department, De Pintelaan 185, (2P1) B-9000 Ghent, Belgium. LeenK.Maes@Ugent.be
Vinck
Bart M
BM
De Vel
Eddy
E
D'haenens
Wendy
W
Bockstael
Annelies
A
Keppler
Hannah
H
Philips
Birgit
B
Swinnen
Freya
F
Dhooge
Ingeborg
I
D000328:Adult; D001309:Auditory Threshold / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D001844:Bone Conduction / Q000502:physiology; D004576:Electromyography / Q000379:methods / Q000592:standards; D005071:Evoked Potentials / Q000502:physiology*; D005246:Feedback / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D019416:Head Movements / Q000502:physiology; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D009334:Neck Muscles / Q000294:innervation / Q000502:physiology*; D015588:Observer Variation; D009801:Oculomotor Muscles / Q000294:innervation / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology*; D015203:Reproducibility of Results; D014722:Vestibule, Labyrinth / Q000502:physiology*; D055815:Young Adult