Colletti V, Fiorino F G
ENT Department, University of Verona, Italy.
Acta Otolaryngol. 1993 Nov;113(6):746-54. doi: 10.3109/00016489309135895.
To facilitate identification and preservation of the auditory nerve during cerebello-pontine angle surgery, bipolar recording of cochlear nerve compound action potentials (CNAPs) was performed. Two silver wires insulated with teflon up to the exposed ends were utilized as electrodes. They were twisted together, the distance between the two tips being 1 mm or less. Rarefaction polarity clicks (31/s) ranging from the psychoacoustical threshold to 120 dB pe SPL were used as stimuli. The investigation was performed in three groups of patients. The first group consisted of 9 patients submitted to vestibular neurectomy and 4 patients operated on by microvascular decompression of the eighth nerve. The second group comprised 8 patients with acoustic tumors smaller than 2 mm and serviceable hearing. Postoperative audiometric results in the subjects in the second group were compared with those obtained in well-matched homogeneous controls consisting of patients with acoustic neuroma operated on without the aid of CNAP recording. Bipolar recording from the eighth nerve was extremely selective, a good response being obtained only when positioning the electrode on the cochlear portion of the eighth nerve. During removal of the acoustic neuroma, repeated bipolar probing of the tumor and eighth nerve facilitated the task of distinguishing the cochlear nerve from other nervous structures and from the tumor, and contributed to preserving hearing in most patients.
为便于在桥小脑角手术中识别和保留听神经，进行了耳蜗神经复合动作电位（CNAPs）的双极记录。两根用聚四氟乙烯绝缘至裸露端的银丝用作电极。将它们绞合在一起，两个尖端之间的距离为1毫米或更小。使用从心理声学阈值到120 dB pe SPL的稀疏极性咔嗒声（31次/秒）作为刺激。该研究在三组患者中进行。第一组包括9例接受前庭神经切除术的患者和4例接受第八神经微血管减压手术的患者。第二组包括8例小于2毫米且听力尚好的听神经瘤患者。将第二组受试者的术后听力测试结果与由未借助CNAP记录进行手术的听神经瘤患者组成的匹配良好的同质对照组的结果进行比较。第八神经的双极记录具有极高的选择性，只有将电极置于第八神经的耳蜗部分时才能获得良好的反应。在切除听神经瘤期间，对肿瘤和第八神经进行反复双极探测有助于将耳蜗神经与其他神经结构以及肿瘤区分开来，并有助于在大多数患者中保留听力。
