MSA ENT Academy Center, Cassino, Italy.
Ear Hear. 2012 Jul-Aug;33(4):508-20. doi: 10.1097/AUD.0b013e3182498c09.
The aim of this study was to investigate the effect of superior semicircular canal dehiscence (SSCD) on the n10 component of the ocular vestibular evoked myogenic potential (oVEMP n10) and the p13-n23 component of the cervical vestibular evoked myogenic potential (cVEMP p13-n23) evoked by 500 Hz bone-conducted vibration (BCV) at the midline forehead at the hairline (Fz) in 26 patients with computed tomography-verified SSCD. Previous evidence has led to the proposal that the oVEMP n10 is of utricular origin whereas the cVEMP p13-n23 is of saccular origin. The question is can the oVEMP n10 to 500 Hz BCV indicate SSCD?
A hand-held Bruel & Kjaer 4810 Minishaker was used to provide BCV stimulation using surface electromyography electrodes to record oVEMP n10 and cVEMP p13-n23. The stimulus was 7 msec bursts of 500 Hz BCV at either Fz or at the vertex of the skull (Cz). Twenty-seven healthy subjects were tested in the same paradigm.
In response to 500 Hz Fz BCV in SSCD patients the oVEMP n10 amplitude beneath the contraSSCD eye was substantially and significantly larger than the oVEMP n10 beneath the ipsiSSCD eye, whereas in these same patients the cVEMP p13-n23 amplitude over the ipsiSSCD sternocleidomastoid muscle to Fz BCV was slightly but significantly larger than the cVEMP p13-n23 amplitude over the contraSSCD sternocleidomastoid muscle. In SSCD patients there was a significant relationship between the size of the dehiscence and the amplitude of the contralateral oVEMP n10 potential. The oVEMP n10 to Cz stimulation was still present in SSCD patients, but small or absent in healthy subjects.
In response to 500 Hz Fz BCV an asymmetrical oVEMP n10 with a significantly increased amplitude of contralesional oVEMP n10 (compared with population values of healthy subjects) is a simple useful indicator of SSCD, confirmed by the Cz response. oVEMP testing with 500 Hz Fz BCV allows very simple, very fast identification of a probable unilateral SSCD.
本研究旨在探讨上半规管裂（SSCD）对中线上额（Fz）发际线处 500Hz 骨导振动（BCV）诱发的眼震性前庭诱发肌源性电位（oVEMP n10）和颈性前庭诱发肌源性电位（cVEMP p13-n23）n10 成分的影响，26 例经 CT 证实的 SSCD 患者在 Fz 处接受 500Hz BCV 刺激。先前的证据表明，oVEMP n10 起源于椭圆囊，而 cVEMP p13-n23 起源于球囊。问题是，500Hz BCV 诱发的 oVEMP n10 能否提示 SSCD？
使用 Bruel & Kjaer 4810 迷你振荡器作为手持设备，通过表面肌电图电极记录 oVEMP n10 和 cVEMP p13-n23，进行 BCV 刺激。刺激为 7ms 时的 500Hz BCV 爆发，分别在 Fz 或颅骨顶点（Cz）处。27 名健康受试者在相同的范式下接受测试。
在 SSCD 患者对 500Hz Fz BCV 的反应中，对侧 SSCD 眼下方的 oVEMP n10 振幅明显大于同侧 SSCD 眼下方的 oVEMP n10 振幅，而在这些相同的患者中，同侧 SSCD 胸锁乳突肌相对于 Fz BCV 的 cVEMP p13-n23 振幅略高于对侧 SSCD 胸锁乳突肌。在 SSCD 患者中，裂隙大小与对侧 oVEMP n10 电位振幅之间存在显著关系。在 SSCD 患者中，500Hz Cz 刺激仍存在 oVEMP n10，但在健康受试者中较小或缺失。
在 500Hz Fz BCV 刺激下，对侧 oVEMP n10 出现不对称、振幅明显增加（与健康受试者的人群值相比）是 SSCD 的一个简单有用指标，Cz 反应可证实这一点。500Hz Fz BCV 诱发的 oVEMP 测试可非常简单、快速地识别单侧 SSCD 的可能性。
