This study was performed to compare three electrode configurations for the ocular vestibular evoked myogenic potentials (oVEMPs)—“standard,” “sternum,” and “nose”—by making use of bone-conducted stimuli (at the level of Fz with a minishaker). In the second part, we compared the test–retest reliability of the standard and nose electrode configuration on the oVEMP parameters.
This study had a prospective design. Fourteen healthy subjects participated in the first part (4 males, 10 females; average age = 23.4 (SD = 2.6) years; age range 19.9 to 28.3 years) and second part (3 males, 11 females; average age = 22.7 (SD = 2.4) years; age range 20.0 to 28.0 years) of the study. OVEMPs were recorded making use of a hand-held bone conduction vibrator (minishaker). Tone bursts of 500 Hz (rise/fall time = 2 msec; plateau time = 2 msec; repetition rate = 5.1 Hz) were applied at a constant stimulus intensity level of 140 dB FL.
PART 1: The n10–p15 amplitude obtained with the standard electrode configuration (mean = 15.8 μV; SD = 6.3 μV) was significantly smaller than the amplitude measured with the nose (Z = −3.3; p = 0.001; mean = 35.0 μV; SD = 19.1 μV) and sternum (Z = −3.3; p = 0.001; mean = 27.1 μV; SD = 12.2 μV) electrode configuration. The p15 latency obtained with the nose electrode configuration (mean = 14.2 msec; SD = 0.54 msec) was significantly shorter than the p15 latency measured with the standard (Z = −3.08; p = 0.002) (mean = 14.9 msec; SD = 0.75 msec) and sternum (Z = −2.98; p = 0.003; mean = 15.4 msec; SD = 1.07 msec) electrode configuration. There were no differences between the n10 latencies of the three electrode configurations. The 95% prediction intervals (given by the mean ± 1.96 * SD) for the different interocular ratio values were [−41.2; 41.2], [−37.2; 37.2], and [−25.9; 25.9] for standard, sternum, and nose electrode configurations, respectively. PART 2: Intraclass correlation (ICC) values calculated for the oVEMP parameters obtained with the standard electrode configuration showed fair to good reliability for the parameters n10–p15 amplitude (ICC = 0.51), n10 (ICC = 0.52), and p15 (ICC = 0.60) latencies. The ICC values obtained for the parameters acquired with the nose electrode configuration demonstrated a poor reliability for the n10 latency (ICC = 0.37), a fair to good reliability for the p15 latency (ICC = 0.47) and an excellent reliability for the n10–p15 amplitude (ICC = 0.85).
This study showed the possible benefits from alternative electrode configurations for measuring bone-conducted-evoked oVEMPs in comparison with the standard electrode configuration. The nose configuration seems promising, but further research is required to justify clinical use of this placement.
1ENT Department, Sint-Augustinus Hospital Antwerp, European Institute for ORL-HNS, Antwerp, Belgium; 2Antwerp University Research center for Equilibrium and Aerospace (AUREA), ENT Department, University Hospital Antwerp, Antwerp, Belgium; 3Faculty of Medicine and Health Sciences, Department of Otorhinolaryngology, Ghent University, Ghent, Belgium; and 4Faculty of Medicine and Health Sciences, Department of Speech, Language and Hearing Sciences, Ghent University, Ghent, Belgium.
The authors have no conflicts of interest to disclose.
Received July 10, 2015; accepted August 13, 2016.
Address for correspondence: Robby Vanspauwen, ENT Department, Sint-Augustinus Hospital Antwerp, European Institute for ORL-HNS, Oosterveldlaan 24, 2610 Wirlijk - Antwerp, Belgium. E-mail: firstname.lastname@example.org