著者

沖津 卓二 草刈 潤 富岡 幸子 伊藤 和也

出版者

耳鼻咽喉科臨床学会

雑誌

耳鼻咽喉科臨床 (ISSN:00326313)

巻号頁・発行日

vol.72, no.12, pp.1591-1597, 1979

被引用文献数

1

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Auditory brainstem electric response (ABR) is generally recorded as the potential difference between the electrode on the ear lobe and on the vertex [Lobe-Vertex recording]. Among the five waves recorded the latency and the presence or absence or Wave I and V are particularly important factors.<br>The purpose of the present study was to obtain a clear appearance of Waves I and V even at the low intensity of sound by simultaneous performance of Lobe-Vertex and Membrane-Vertex recordings. As the tone stimulus is decreased toward the subjective threshold in Lobe-Vertex recording, each wave becomes smaller, and the waves, except for Wave V are frequently undetectable near the threshold.<br>On the other hand, in the recording of the potential difference between the electrodes on the posterior marginal portion of the tympanic membrane and on the vertex [Membrane-Vertex recording], Wave I is larger and Wave V smaller than that of Lobe-Vertex recording, and the clearly detectable Wave I can be obtained by the tone stimulus near the subjective threshold. Namely, the detectability of Wave I and V depends on the site of the recording electrode and there is no statistical difference between the two recording methods regarding latencies of the two waves.<br>Typical wave patterns recorded from three patients were demonstrated: two of acoustic tumor and the other of a C-P angle tumor.<br>In one patient with an acoustic tumor and the one with an C-P angle tumor, although no waves were detected in Lobe-Vertex recording, Wave I was clearly detected in Membrane-Vertex recording.<br>In the other patient with an acoustic tumor, Waves I and V were not so clearly detected in Love-Vertex recording, but in Membrane-Vertex recording, Waves I and V were clearly detected and the prolongation of the latency interval between Waves I and V could be measured.<br>From these results, it is suggested that the simultaneous Lobe-Vertex and Membrane-Vertex recording technique in ABR is most useful for the detection of cochlear nerve and the brainstem disorders.