Effects of cochlear implants on otolith function as evaluated by vestibulo-ocular reflex and vestibular evoked myogenic potentials
Effects of cochlear implants on otolith function as evaluated by vestibulo-ocular reflex and vestibular evoked myogenic potentials
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DOI：
10.1016/j.anl.2019.03.011
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发表时间：
2019-12-01
影响因子：
1.7
通讯作者：
Inohara, Hidenori
中科院分区：
文献类型：
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作者：
Imai, Takao;Okumura, Tomoko;Inohara, Hidenori
目的：本研究的目的是探讨人工耳蜗术后是否伴有耳石功能的恶化。方法：对2016年5月至2017年11月收治的12例双侧重度感音神经性聋患者行人工耳蜗术前、术后的颈、眼前庭诱发肌源性电位(CVEMP)和眼前庭诱发肌源性电位(OVEMP)及偏心旋转时的线性前庭眼反射(LVOR)检测，评价耳石功能。CVEMP和oVEMP采用不对称比(AR)计算，计算公式为：[(非手术侧p13和n23波幅之和)-(手术侧)]/[(非手术侧)+(手术侧)]。用偏心旋转时的VOR增益与中心旋转时的VOR增益之比来评估LVOR。对于偏心旋转，患者在偏离旋转轴的同时进行旋转。同时，线加速度刺激了椭圆体，并诱发了左心室震荡。所有患者均于术前和术后30d左右进行cVEMP和oVEMP检测以及中心旋转和偏心旋转试验。结果：排除了3例术前无cVEMP反应的患者，9/12例术前cVEMP检测结果。在其中5例患者中，脑梗塞后cVEMP的AR增加，表明cVEMP评价的球囊功能在术后没有明显恶化。排除1例脑梗塞前无oVEMP反应的患者，将术前oVEMP结果留给11/12例患者。其中10例患者的oVEMP的AR在CI手术后增加，表明oVEMP评估的椭圆形功能在术后显著恶化。然而，由于CI后偏心旋转时的VOR增益与中心旋转时的VOR增益的比值没有变差，所以根据LVOR评估，术后椭圆囊功能没有明显恶化。12例患者中有2例在CI后眩晕症状加重。结论：CI不会导致cVEMP评价的球囊功能恶化。虽然CI在oVEMP测试中确实会导致椭圆球功能的恶化，但在LVOR测试中这一点并不一致。这些结果表明，CI引起椭圆形功能的轻微恶化，不足以引起眩晕或LVOR的恶化。(C)2019爱思唯尔B.V.保留所有权利。
Objective: The aim of this study was to investigate whether the insertion of an implant into the cochlea is accompanied by a deterioration in otolith function. Cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP) and linear vestibulo-ocular reflex (lVOR) during eccentric rotation were assessed before and after cochlear implantation (CI) to evaluate otolith function.Methods: Twelve patients with bilateral severe sensorineural hearing loss who had undergone CI surgery in our hospital between May 2016 and November 2017 were included in this study. cVEMP and oVEMP were assessed using the asymmetry ratio (AR), calculated with the following formula: [(peakto-peak amplitude calculated as the sum of the p13 and n23 amplitudes in the non-operated side) - (that in the operated side)]/[(that in the non-operated side) + (that in the operated side)]. The ratio of VOR gain during eccentric rotation against VOR gain during center rotation was used to assess lVOR. For eccentric rotation, patients were rotated while displaced from the axis of rotation. At the same time, linear acceleration stimulated the utricle and induced lVOR. All patients underwent cVEMP and oVEMP tests and center and eccentric rotation tests before and about 30 days after CI surgery.Results: Three patients with absent cVEMP responses before surgery were excluded, leaving pre-surgery cVEMP results for 9/12 patients. In five of these patients, the AR of cVEMP increased after CI, indicating that saccular function, as evaluated by cVEMP, did not deteriorate significantly postoperatively. One patient with an absent oVEMP response before CI was excluded, leaving pre-surgery oVEMP results for 11/12 patients. In 10 of these patients, the AR of oVEMP increased after CI surgery, indicating that utricular function, as evaluated by oVEMP, deteriorated significantly postoperatively. However, because the ratio of VOR gain during eccentric rotation against VOR gain during center rotation did not become worse after CI, utricular function, as evaluated by lVOR, did not deteriorate significantly postoperatively. Symptoms of vertigo became worse after CI in two of the 12 patients.Conclusion: CI does not cause a deterioration in saccular function, as evaluated by cVEMP. Although CI does cause a deterioration in utricular function in oVEMP tests, this is not consistent in lVOR tests. These results indicate that CI causes a slight deterioration in utricular function that is insufficient to cause vertigo or deterioration of lVOR. (C) 2019 Elsevier B.V. All rights reserved.