OBJECTIVE Recording derivations for intraoperative brainstem auditory evoked potential (BAEP) monitoring consist of a preauricular electrode referenced to Cz'. These derivations are prone to unfavorable signal amplitude. This study analyses whether an alternative noncephalic electrode positioned over ipsilateral Erb's point, thereby generating a new Erb's point-vertex recording derivation, improves BAEP recordings. METHODS Electrodes were placed preauricularly (A1/A2) and at left and right Erb's point (EP1/EP2). They were referenced to Cz'. Click sound stimulation (80-95 dB above hearing level) was applied. At intraoperative baseline conditions, latencies and amplitudes of waves I-V of all derivations were analyzed. RESULTS Data of 30 patients (54 ± 15 years/17 females) with normal hearing or mild symmetrical presbycusis undergoing infratentorial surgeries (15 microvascular decompressions) were analyzed. Using EP1-Cz'/EP2-Cz' derivations compared to A1-Cz'/A2-Cz', amplitudes for wave IV (left +65%, p < 0.001; right +43%, p = 0.002) and wave V (left +54%, p < 0.001; right +48%, p < 0.001) were significantly increased. Only in the left (EP1) derivation, there was a tendency towards less reproducibility of wave I, resulting in a decrease of amplitude (-35%, p = 0.005). CONCLUSIONS Adding an Erb's point electrode derivation resulted in larger amplitudes of waves IV to V. whereas conventional preauricular or mastoid derivation is preferential for wave I assessment. SIGNIFICANCE Increased wave amplitudes facilitate detection of pathologically reduced wave forms (wave V in particular) which represents a significant advancement.

中文翻译：

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术中 Erb 的点顶点记录增加脑干听觉诱发电位波 V 幅值

目的 术中脑干听觉诱发电位 (BAEP) 监测的记录推导包括一个以 Cz' 为参考的耳前电极。这些推导容易产生不利的信号幅度。本研究分析了替代的非头电极是否位于同侧 Erb 点上，从而产生新的 Erb 点-顶点记录推导，改善 BAEP 记录。方法电极放置在耳前（A1/A2）和左右Erb点（EP1/EP2）。它们被引用到 Cz'。应用点击声刺激（高于听力水平 80-95 dB）。在术中基线条件下，分析了所有推导的 IV 波的延迟和幅度。结果 分析了 30 名接受幕下手术（15 次微血管减压术）的听力正常或轻度对称性老耳病患者（54 ± 15 岁/17 名女性）的数据。使用 EP1-Cz'/EP2-Cz' 推导与 A1-Cz'/A2-Cz' 相比，波 IV（左 +65%，p < 0.001；右 +43%，p = 0.002）和波 V（左 +54%，p < 0.001；右 +48%，p < 0.001) 显着增加。仅在左侧 (EP1) 推导中，波 I 的可重复性趋于降低，导致振幅降低 (-35%, p = 0.005)。结论 添加 Erb 的点电极推导导致波 IV 到 V 的更大振幅。而传统的耳前或乳突推导优先用于波 I 评估。