Dalbert Adrian, Huber Alexander, Veraguth Dorothe, Roosli Christof, Pfiffner Flurin
University of Zurich and Department of Otorhinolaryngology-Head and Neck Surgery, University Hospital Zurich, Zurich, Switzerland.
Otol Neurotol. 2016 Jun;37(5):446-53. doi: 10.1097/MAO.0000000000000998.
To assess cochlear trauma during cochlear implantation by electrocochleography (ECoG) and cone beam computed tomography (CBCT) and to correlate intraoperative cochlear trauma with postoperative loss of residual hearing.
ECoG recordings to tone bursts at 250, 500, 750, and 1000 Hz and click stimuli were recorded before and after insertion of the cochlear implant electrode array, using an extracochlear recording electrode. CBCTs were conducted within 6 weeks after surgery. Changes of intraoperative ECoG recordings and CBCT findings were correlated with postoperative threshold shifts in pure-tone audiograms.
Fourteen subjects were included. In three subjects a decrease of low-frequency ECoG responses at 250, 500, 750, and 1000 Hz occurred after insertion of the electrode array. This was associated with no or minimal residual hearing 4 weeks after surgery. ECoG responses to click stimuli were present in six subjects and showed a decrease after insertion of the electrode array in three. This was associated with a mean hearing loss of 21 dB in postoperative pure-tone audiograms. Scalar dislocation of the electrode array was assumed in one subject because of CBCT findings and correlated with a decrease of low-frequency ECoG responses and a complete loss of residual hearing.
Hearing loss of ≤11 dB is not associated with detectable decrease in ECoG recordings during cochlear implantation. However, in a majority of patients with threshold shifts of >11 dB or complete hearing loss, an intraoperative decrease of high- or low-frequency ECoG signals occurs, suggesting acute cochlear trauma.
通过电耳蜗图（ECoG）和锥形束计算机断层扫描（CBCT）评估人工耳蜗植入过程中的耳蜗损伤，并将术中耳蜗损伤与术后残余听力丧失相关联。
使用耳蜗外记录电极，在人工耳蜗植入电极阵列插入前后记录对250、500、750和1000赫兹短纯音以及短声刺激的ECoG记录。术后6周内进行CBCT检查。术中ECoG记录的变化和CBCT结果与纯音听力图中的术后阈值变化相关联。
纳入14名受试者。在3名受试者中，电极阵列插入后，250、500、750和1000赫兹的低频ECoG反应降低。这与术后4周无残余听力或残余听力极少相关。6名受试者存在对短声刺激的ECoG反应，其中3名在电极阵列插入后反应降低。这与术后纯音听力图中平均21分贝的听力损失相关。由于CBCT结果，一名受试者被认为电极阵列出现了鼓阶脱位，这与低频ECoG反应降低和残余听力完全丧失相关。
人工耳蜗植入过程中，听力损失≤11分贝与ECoG记录中可检测到的降低无关。然而，在大多数阈值变化>11分贝或完全听力丧失的患者中，术中高频或低频ECoG信号会降低，提示急性耳蜗损伤。
