Verma N P, Dela Cruz C
Wayne State University School of Medicine, Allen Park, MI.
Clin Electroencephalogr. 1988 Oct;19(4):231-4. doi: 10.1177/155005948801900411.
We utilized an ipsilateral to contralateral earlobe (Ai-Ac) derivation in addition to the scalp to ipsilateral ear (Cz-Ai) and scalp to contralateral ear (Cz-Ac) derivations, in 12 normal hearing community volunteers and 36 patients with a variety of referrals and varying degrees of hearing loss. In normal subjects, the latency of wave I in the Ai-Ac derivation was identical to that in Cz-Ai, but amplitude was consistently smaller (0.21 +/- 0.1 vs. 0.30 +/- 0.13 microV, p less than 0.005). The wave III behaved in a reverse manner. These data can be easily explained based on traditional principles of near- and far-field potentials. The amplitude differences of the wave I in Cz-Ai and Ai-Ac derivations were, however, small and the phase-reversals of that wave between the 2 derivations were striking and consistent in all subjects and patients. This observation indicates that the addition of Ai-Ac derivation to the conventional 1 or 2 channel montage may aid in the identification of wave I.
我们在12名听力正常的社区志愿者和36名因各种原因转诊且听力损失程度不同的患者中，除了采用头皮到同侧耳朵（Cz - Ai）和头皮到对侧耳朵（Cz - Ac）的导联方式外，还采用了同侧到对侧耳垂（Ai - Ac）的导联方式。在正常受试者中，Ai - Ac导联中I波的潜伏期与Cz - Ai导联中的相同，但振幅始终较小（0.21±0.1与0.30±0.13微伏，p<0.005）。III波的表现则相反。基于近场和远场电位的传统原理，这些数据很容易解释。然而，Cz - Ai和Ai - Ac导联中I波的振幅差异较小，且该波在两个导联之间的相位反转在所有受试者和患者中都很明显且一致。这一观察结果表明，在传统的单通道或双通道组合中增加Ai - Ac导联可能有助于识别I波。
