Text

Perbandingan dan Korelasi Ambang Respons Auditorik Batang Otak dengan Ambang Respons Auditorik Kortikal pada Hewan Coba Kucing menggunakan Stimulus Akustik = Comparison and Correlation of Auditory Brainstem Response Threshold and Auditory Cortical Response Threshold in Cats using Acoustic Stimulus.

Ambang respons auditorik batang otak dan ambang respons auditorik kortikal telah digunakan untuk menilai fungsi pendengaran. Akan tetapi, belum terdapat penelitian yang membandingkan dan mengkorelasikan ambang respons auditorik batang otak dan ambang respons auditorik intrakortikal. Penelitian ini bertujuan mencari tahu apakah terdapat perbedaan bermakna dan korelasi antara ambang respons auditorik pada batang otak, korteks auditorik primer (A1) dan posterior auditory field (PAF) hewan coba kucing dengan stimulus akustik. Penelitian ini juga bertujuan mencari tahu ada tidaknya perbedaan bermakna antara ambang respons auditorik kortikal yang ditentukan dengan perbandingan amplitudo prestimulus–post-stimulus dan inter-trial phase coherence (ITPC). Perekaman pada 5 ekor kucing dilakukan di bawah anestesi isoflurane. Respons auditorik batang otak direkam dengan elektrode permukaan, sedangkan respons auditorik A1 dan PAF direkam dengan elektrode invasif intrakortikal. Ambang respons auditorik kortikal ditentukan dengan perbandingan amplitudo pre-stimulus–post-stimulus dan ITPC dan ambang respons auditorik batang otak ditentukan dengan ITPC. Tidak terdapat perbedaan bermakna antara ambang respons auditorik kortikal yang ditentukan dengan perbandingan amplitudo pre-stimulus–post-stimulus dan ITPC (p=0,673). Ambang respons auditorik batang otak ditemukan berbeda bermakna dengan ambang respons auditorik kortikal (p < 0,001), dengan median paling rendah pada batang otak dan paling tinggi pada PAF. Tidak ditemukan korelasi antar ambang respons auditorik batang otak–A1 (r = 0,066, p = 0,189), batang otak–PAF (r = – 0,099, p = 0,062), dan A1–PAF (r = 0,181, p = 0,001). Penelitian ini menunjukkan bahwa ITPC berpotensi digunakan untuk menilai ambang respons auditorik batang otak dan kortikal secara objektif tanpa data pre-stimulus. Peningkatan ambang respons auditorik tanpa adanya korelasi sepanjang hierarki jaras pendengaran kemungkinan menggambarkan kompleksitas jaras pendengaran, terutama pada korteks auditorik.Oleh karena itu, walaupun berpotensi membantu diagnosis pada kasus gangguan pendengaran sentral, penilaian pendengaran dengan ambang respons auditorik kortikal perlu diinterpretasikan dengan hati-hati.
Kata kunci: penilaian ambang auditorik, ambang respons auditorik kortikal, ambang respons auditorik batang otak, korteks auditori, hewan coba kucing, stimulus akustik


Auditory brainstem response threshold and auditory cortical response threshold have been used to assess hearing function. However, there has not been any research that compares and correlates auditory brainstem response threshold and auditory intracortical response threshold. As such, this study aims to find out whether there are any significant difference and correlation between brainstem, primary auditory cortex (A1), and posterior auditory field (PAF) auditory response thresholds in cats as animal models using acoustic stimulus. This study also aims to find out whether there is any significant difference between auditory cortical response thresholds obtained from two different methods, namely pre-stimulus–post-stimulus amplitude comparison and inter-trial phase coherence (ITPC). Recordings were done on 5 cats under isoflurane anesthesia. Auditory brainstem responses were recorded with surface electrodes, while auditory cortical responses in A1 and PAF were recorded with invasive intracortical electrodes. Auditory cortical response thresholds were determined using both pre-stimulus–post-stimulus amplitude comparison and ITPC, while auditory brainstem response thresholds were determined using ITPC. There was no significant difference between auditory cortical response thresholds obtained from both methods (p=0,673). Auditory brainstem response thresholds were found to be significantly different from auditory cortical response thresholds in both A1 (p < 0,001) and PAF (p < 0,001), with the lowest median in brainstem and highest median in PAF. No correlation was found between auditory response thresholds in brainstem–A1 (r = 0,066, p = 0,189), brainstem–PAF (r = –0,099, p = 0,062), and A1–PAF (r = 0,181, p = 0,001). This study demonstrates that ITPC has the potential to objectively assess brainstem and cortical auditory response thresholds without pre-stimulus data. The increase in auditory response threshold across the auditory pathway with an absence of significant correlation between the thresholds indicate the increasing complexity of the auditory pathway, especially the auditory cortex. Therefore, despite its potential to aid diagnosis in cases of central hearing loss, hearing assessments using cortical auditory response thresholds need to be interpreted with caution.
Keywords: auditory threshold assessment, auditory cortical response threshold, auditory brainstem response threshold, auditory cortex, cats as animal model, acoustic stimulus