Zhou et al.(66 Zhou G, Gopen Q, Kenna MA. Delineating the hearing loss in children with enlarged vestibular aqueduct. Laryngoscope. 2008;118(11):2062-6. http://dx.doi.org/10.1097/MLG.0b013e31818208ad. PMid:18665003.
http://dx.doi.org/10.1097/MLG.0b013e3181...
) |
54 patients (22 male and 32 female) with EVA, age range between 2 and 16 years and an average of 7 years. |
Not reported by the authors. |
The acoustic stimulus used was a 500 Hz tone burst, intensity of 90 dB nHL, through ER-3A insert headphones. |
All patients with EVA had hearing loss, although the degree and configuration of hearing loss varied considerably. The VEMP test was performed on 14 patients with EVA; In all ears with the syndrome, except one, increased test responses were found: decreased thresholds in ears with EVA in relation to normal and increased amplitude. |
Zhou & Gopen(55 Zhou G, Gopen Q. Characteristics of vestibular evoked myogenic potentials in children with enlarged vestibular aqueduct. Laryngoscope. 2011;121(1):220-5. http://dx.doi.org/10.1002/lary.21184. PMid:21132770.
http://dx.doi.org/10.1002/lary.21184...
) |
A total of 25 cases (37 ears), 13 with unilateral EVA and 12 with bilateral EVA, were included for analysis. |
Sitting, the patient was asked to turn the head to the side contralateral to the tested ear. |
Electrodes were placed on the SCM muscle. VEMP responses were obtained using acoustic tone burst stimuli of 250 and 500 Hz, through insert headphones. The lowest stimulus intensity at which a clear and repeatable biphasic wave (P1/N1) was observed was recorded as the VEMP threshold. If no repeatable response was found, the VEMP was considered absent. VEMP amplitude and P1/N1 latencies were measured at the stimulus level of 90 dB nHL. |
Characteristics of VEMP in EVA include lower thresholds and higher amplitudes. |
| The abnormally low VEMP threshold suggested a “third window” effect in this pathological condition. The unilateral absence of VEMP responses in children with EVA may be indicative of peripheral vestibular dysfunction. VEMP testing is recommended in the evaluation of children with EVA. |
| The average age of these patients was 8.2 years. |
Yang et al.(1616 Yang CJ, Lavender V, Meinzen-Derr JK, Cohen AP, Youssif M, Castiglione M, et al. Vestibular pathology in children with enlarged vestibular aqueduct. Laryngoscope. 2016;126(10):2344-50. http://dx.doi.org/10.1002/lary.25890. PMid:26864825.
http://dx.doi.org/10.1002/lary.25890...
) |
27 patients diagnosed with EVA, 37% with unilateral involvement and 63% bilateral. The age range varied from 3 to 12 years old. |
To perform the VEMP, the SmartEP analyzer from Intelligent Hearing Systems (Miami, FL) was used. |
The surface electrodes were placed in the following positions: active on the SCM muscle, reference on the sternoclavicular junction and grounding on the forehead. |
15% of patients had abnormal cVEMP results. There was no statistically significant correlation between absolute cVEMP thresholds and amplitudes and age, clinical symptoms, audiometric or radiographic findings. All analyses were performed using SAS for Windows 9.3 (SAS Institute Inc., Cary, NC). |
| Children were instructed to contract the SCM by rotating the head in a sitting or lying supine position at a 20-degree angle and contract the SCM by elevating the head. |
| The acoustic stimulus used was a 500 Hz tone burst, intensity of 107 dB nHL, through an ER-3A insert earphone at a rate of 5.1. |
Zhang et al.(22 Zhang Y, Chen Z, Zhang Y, Hu J, Wang J, Xu M, et al. Vestibular-evoked myogenic potentials in patients with large vestibular aqueduct syndrome. Acta Otolaryngol. 2020 Nov 26;140(1):40-5. http://dx.doi.org/10.1080/00016489.2019.1687937. PMid:31769324.
http://dx.doi.org/10.1080/00016489.2019....
) |
29 patients diagnosed with enlarged vestibular aqueduct (EVA) syndrome, 23 children (3 to 12 years old) and 6 adults (15 to 33 years old) |
To perform the VEMP, the Otometrics (Taastrup, Denmark) ICS Chartr EP analyzer was used. The patient remained lying in the supine position and was instructed to raise their head 30° when listening to the sound in the headphones. |
The surface electrodes were placed in the following positions: active on the SCM muscle bilaterally, reference above the sternoclavicular joint, and grounding on the midline of the forehead. The acoustic stimulus used was a 500 Hz tone burst. VEMP thresholds were recorded as lower stimulus intensities that could cause a repeatable and clear biphasic wave. |
VEMP parameters were recorded from the elicited short-latency reproducible biphasic waveform. The Pearson chi-square test or Fisher's exact test were used to compare response rates. The t-test was used to compare thresholds, amplitudes, P1 and N1 latencies and latencies between peaks. Collected data were analyzed with IBM SPSS Statistics version 19.0.0 (IBM SPSS Statistics, Armonk, NY). |
Liu et al.(1717 Liu X, Ren L, Li J, Ji F, Liu X, Du Y, et al. Air and bone-conducted vestibular evoked myogenic potentials in children with large vestibular aqueduct syndrome. Acta Otolaryngol. 2021;141(1):50-6. http://dx.doi.org/10.1080/00016489.2020.1815836. PMid:32964775.
http://dx.doi.org/10.1080/00016489.2020....
) |
54 children, 44 with enlarged vestibular aqueduct syndrome as the study group and 10 normal-hearing children as the control group. Patients over 14 years of age were excluded from the study. |
To perform the cVEMP, the Eclipse equipment (Interacoustics A/S, Denmark) was used. The cVEMP test was performed with patients sitting and instructed to turn their head to the side contralateral to the stimulus, both via air and bone conduction . |
The surface electrodes were placed in the following positions: active on the manubrium of the sternum, reference on the superior position of the sternocleidomastoid muscle (SCM) and grounding on the forehead. |
cVEMP thresholds by air conduction were categorized as “normal” if they were 70 to 80 dB, as “low” if they were 65 dB or less, and as “elevated” if they were greater than 90 dB nHL. Bone conduction cVEMP thresholds were categorized as “low” if they were 25 dB nHL or less, and “high” if they were equal to or greater than 45 dB nHL. |
| Air conduction: the type of stimulus used was 500 Hz tone burst and the stimulation rate was 5.1/s, with an initial intensity of 100 dB nHL with steps of 5 or 10 dB to elicit the threshold. The high-pass filter was 10 Hz and the low-pass filter was 750 Hz. The recording window was defined from 20 to 80 ms. 200 stimuli were used and the P wave was set to the upward direction. Bone conduction: B-81 bone transducer, mastoid placement. Initial stimulation intensity of 70 dB nHL and adjusted to 5 or 10 dB. |
| The Wilcoxon test was applied to analyze the difference in VEMP parameters (P1, N1, P1-N1 latency, amplitude and threshold). The analyses were performed using SPSS 17.0 software (IBM, New York, USA, 2020). |
Thumbnail
