外淋巴瘘对内耳损害的实验研究

经颅骨钻孔，蛛网膜下腔注射加压，对５０只健康豚鼠建立了外淋巴瘘（ＰＬＦ）的实验动 物模型。采用耳蜗电图描记，火棉胶切片及耳蜗铺片法观察内耳功能和形态学变化。结果：在听功能 上，造瘘术后一些动物的蜗神经动作电位（ＡＰ）出现了不同程度地升高；８０ｄＢ Ｎ１波潜伏期随 ＡＰ 阈值升高而延长；在形态学上，内耳存在不同的病理变化．包括前庭膜塌陷或破裂，外淋巴腔积血， 内淋巴水肿和柯替器受压，个别严重损害的耳蜗可见毛细胞破坏。提示：ＰＬＦ若不合并蜗管内其它 损害，单纯的窗膜破裂不引起内耳实质损害；ＰＬＦ内耳病理变化的多样性，决定了其功能表现上无 特异性；对听力下降的治疗，单纯修补瘘孔是不够的。

Experimental study of perilymphatic fistula to inner ear damage

The experimental animal model of perilymphatic fistula (PLF) was made by drilling a small hole in the skull and injecting artificial perilymph into the subarachnoid space in 50 Guinea pigs. The electrocochleography, conventional celloidin embedding and surface preparation techniques were employed for the cochlear functional and morphologic study. The results showed that for the hearing function, the AP threshold increased in some animals after the operation, and the latency of N1 (80 dB) prolonged with the increase of AP threshold.As to the morphology, various pathologic changes were observed in the cochlea, including the collapse or rupture of the Reissner's membrane, hemorrhage in perilymphatic space, endolymphatic hydrops and the compression of the Corti's organ. The hair cell damage could be found in the severely injured individual cochleas. The present study revealed that,if not accompanied by other injury, only the rupture of the window membrane can not cause a sub- stantial damage in the inner ear; owing to the various pathologic changes in the inner ear, there is no specificity in the function 1 the simply repaired window membrane is not enough to improve hearing loss.