腦幹功能障礙之聽覺誘發電位變化

Brain Stem Auditory Evoked Potentials in Brain Stem Dysfunction

陳贊如(Tsan-Ju Chen) ； 許勝光(Hseng-Kuang Hsu) ； 陳順勝(Shun-Sheng Chen)

《The Kaohsiung Journal of Medical Sciences》 4卷4期 (1988/04) Pp. 238-247

https://doi.org/10.6452/KJMS.198804.0238

摘要

本實驗乃為建立腦死之動物模式，在人工可控制之情境下造成老鼠腦幹功能障礙，以研究其腦幹聽覺誘發電位(BAEPS)之變化。選用Long-Evans的雄性大老鼠14隻，體重350-450公克，以sodi-um pentobarbital麻醉之。將兩隻小螺絲釘栓在頭蓋骨上之乳突之額竇骨的部位，但不穿透硬腦膜，以當作記錄電極之用。BAEPS的記錄則採常規的方法。另以鈍頭螺絲釘由頂骨傾斜栓入硬膜外腔中，導致腦幹赫尼亞式〈herniation〉壓迫性之發生，而造成其腦幹功能障礙。將老鼠分成三組，第一組老鼠〈A-D〉持續予以壓迫直到死亡為止，可觀察到其BAEPS之波形從第Ⅳ波往第Ⅰ波逐漸消失；第二組老鼠〈E-I〉在BAEPS之第Ⅳ波消失後才拔出螺絲釘以去除壓迫，可見所有老鼠最後均死亡；第三組老鼠〈J-N〉在第Ⅴ波消失而第Ⅳ波未消失前予以去壓迫，此時所有老鼠均可存活。經由上述實驗，可發現因腦部赫尼亞式壓迫而致腦幹功能障礙時，BAEPS的波形由後往前逐漸消失，其第Ⅳ波之消失可考慮為一腦死之定點變化。無論如何，此關係須再進一步的探討，尤其須加強對老鼠人工呼吸之施予。

並列摘要

To set up an animal model of brain stem death, a pilot experiment of brain stem dysfunction using rats was undertaken. Fourteen adult male Long-Evans rats, weighing 350-450 gm, were anesthetized with sodium pentobarbital. Two screw electrodes were inserted into the skulls on the mastoid and frontal sinus areas without penetrating the dura to serve as cortical recording electrodes. The BAEPS were recorded by routine procedure. The waveⅠthrough Ⅳlatencies of BAE:S in 14 normal rats were (mean±S.D.): 1.53±0.01, 1.97±0.14, 2.80±0.17, 3.81±0.23, 5.17±0.47, 6.41±0.63 msec respectively. Brain stem dysfunction was produced by screwing a dull metal nail into the epidural space of the contralateral parietal bone which resulted in the herniation compression of the brain stem. Continuous compression until death performed in 4 rats and stepwise disappearances of BAEP waves from Ⅳ toⅠwere observed. The other 10 rats were carefully evaluated for both their clinical manifestations and changes of BAEPS. With the occurrence of Cheyne-Stokes respirations, there was a disappearance of waveⅤ&Ⅵ, prolonged latencies ofⅠthrough Ⅳ (1.82±0.28, 2.43±0.36, 3.14±0.41, 4.24±0.44mses) and interpeak latency ofⅠ-Ⅲ(p＜0.01). If decompression was made until the absence of wave Ⅳ, the wave latencies fromⅠtoⅢ could be prolonged and all rats(5 rats) would die. If the screw was pulled out before the disappearance of Ⅳ, all of the five rats would remain alive. The morphologic changes of the brain stem were studied after the rats were sacrificed. In brain stem dysfunction caused by brain herniation, the stepwise absence of wave Ⅳ is considered to be a critical point. However, its relationship to brain stem dysfunction should be further explored, especially after artificial respiratouy care of the rats.

並列關鍵字

brain stem dysfunction ； BAEPS ； brain herniation