Abou-Elew M H, Hosni N A, Obaid E A, Ewida A H
Audio-Vestibular Unit,ORL Department,Otorhinolaryngology Department,Faculty of Medicine,Cairo University,Cairo,Egypt.
Audiology Department,King Faisal Specialist Hospital and Research Center,Jeddah,Saudi Arabia.
J Laryngol Otol. 2017 Apr;131(4):334-340. doi: 10.1017/S0022215117000317.
This study aimed to evaluate the presence of the N3 potential (acoustically evoked short latency negative response) in profound sensorineural hearing loss, its association with the cervical vestibular evoked myogenic potential and the relationship between both potentials and loss of auditory function.
Otological examinations of 66 ears from 50 patients aged from 4 to 36 years were performed, and the vestibular evoked myogenic potential and auditory brainstem response were measured.
The N3 potential was recorded in 36 out of 66 ears (55 per cent) and a vestibular evoked myogenic potential was recorded in 34 (52 per cent). The N3 potential was recorded in 23 out of 34 ears (68 per cent) with a vestibular evoked myogenic potential response and absent in 19 out of 32 ears (59 per cent) without a vestibular evoked myogenic potential response. The presence of an N3 potential was significantly associated with a vestibular evoked myogenic potential response (p = 0.028), but there was no significant difference in the latency or amplitude of the N3 potential in either the presence or absence of a vestibular evoked myogenic potential.
The presence of an N3 potential in profound sensorineural hearing loss with good or poor vestibular function can be explained by the contribution of the efferent cochlear pathway through olivocochlear fibres that join the inferior vestibular nerve. This theory is supported by its early latency and reversed polarity, which is masked in normal hearing by auditory brainstem response waves.
本研究旨在评估极重度感音神经性听力损失中N3电位（听觉诱发短潜伏期负反应）的存在情况、其与颈前庭诱发肌源性电位的关联以及这两种电位与听觉功能丧失之间的关系。
对50例年龄在4至36岁之间患者的66只耳朵进行了耳科检查，并测量了前庭诱发肌源性电位和听觉脑干反应。
66只耳朵中有36只（55%）记录到了N3电位，34只（52%）记录到了前庭诱发肌源性电位。在有前庭诱发肌源性电位反应的34只耳朵中有23只（68%）记录到了N3电位，在无前庭诱发肌源性电位反应的32只耳朵中有19只（59%）未记录到N3电位。N3电位的存在与前庭诱发肌源性电位反应显著相关（p = 0.028），但在前庭诱发肌源性电位存在或不存在的情况下，N3电位的潜伏期或波幅均无显著差异。
在前庭功能良好或不佳的极重度感音神经性听力损失中，N3电位的存在可通过经橄榄耳蜗纤维加入下前庭神经的传出性耳蜗通路的作用来解释。这一理论得到了其早期潜伏期和反向极性的支持，而在正常听力中，这些特征被听觉脑干反应波所掩盖。
