Lambert P R, Ruth R A
Department of Otolaryngology-Head and Neck Surgery, University of Virginia Medical School, Charlottesville 22908.
Otolaryngol Head Neck Surg. 1988 Jun;98(6):575-80. doi: 10.1177/019459988809800607.
Monitoring auditory evoked potentials, especially surface recorded responses (ABR), during neuro-otologic surgery is being widely used. Recording of the most peripheral components of the ABR with surface electrodes can be difficult, however, in patients with hearing loss. To enhance wave I, a newly designed canal electrode for noninvasive electrocochleography (ECoG) has been used. A small reticulated foam plug is inserted in the ear canal and serves as the electrode. The signal is transduced through a center polyethylene tube. The advantages of this system for ECoG are several: (1) simplified signal presentation, obviating the need for custom ear mold or button transducer; (2) large electrode surface area that lowers impedance and improves signal to noise ratio; and (3) stability of the electrode during manipulations within the surgical field. There are several advantages to supplementing ABR with simultaneous ECoG. First, there is a significant enhancement in wave I amplitude, an important factor when monitoring from hearing impaired patients in an operating room environment. Ability to clearly define wave I permits use of the I-V interwave interval, which can be a more sensitive parameter than wave V latency alone. Secondly, more rapid feedback on changes in cochlear function is available since, compared to surface recordings alone, fewer responses need to be averaged.
在神经耳科手术期间监测听觉诱发电位，尤其是表面记录的反应（ABR），正被广泛应用。然而，对于听力损失患者，使用表面电极记录ABR最外周成分可能会很困难。为了增强I波，一种新设计的用于无创耳蜗电图（ECoG）的耳道电极已被使用。一个小的网状泡沫塞插入耳道并作为电极。信号通过中心聚乙烯管进行传导。该系统用于ECoG的优点有几个：（1）简化信号呈现，无需定制耳模或纽扣式换能器；（2）电极表面积大，降低了阻抗并提高了信噪比；（3）在手术视野内操作期间电极的稳定性。同时进行ECoG补充ABR有几个优点。首先，I波幅度有显著增强，这在手术室环境中监测听力受损患者时是一个重要因素。能够清晰定义I波允许使用I-V波间期，它可能是比单独的V波潜伏期更敏感的参数。其次，由于与仅进行表面记录相比，需要平均的反应更少，所以可以更快地反馈耳蜗功能的变化。
