Study of electron microscopical structure and taste function of regenerated chorda tympani nerve after severance during middle ear surgery

1.神经修复的方法及再生鼓索神经的发生率中耳手术切断鼓索神经后，近、远侧残端在颞肌筋膜上不缝合。即使造成神经缺损处，近端和远端的断端几乎都被置于颞肌筋膜的原始位置，而不需要神经移植。中耳胆脂瘤二期手术中，重建鼓膜黏膜下层可见再生神经。鼓索神经再生率为46%(33/71例)。33例鼓索神经再生患者中，61%(20/33例)有味觉功能。在87例中耳手术中鼓索神经切断的患者中，24%(21/87例)的患者在Eather电测法或滤纸片法…中显示味觉功能恢复更多.3。第Ⅱ期鼓索神经再生和味觉功能恢复病例的菌状乳头形态(分布和大小)研究，用数字显微镜观察菌状乳头的分布和大小，并将其形态记录在记忆卡中。菌状乳头的分布分为三组。(1)双侧舌乳头分布无明显差异。(2)双方在分布上存在差异。(3)舌切断侧菌状乳头完全变性。在35例神经切断后味觉功能恢复的患者中，1组占31%，2组占69%；87例味觉功能未恢复的患者中，2组占61%，3组占39%。较少

1. Method of nerve repair and incidence of regenerated chorda tympani nerveAfter the chorda tympani nerve was severed during middle ear surgery, the proximal and distal stumps were anastomosed without suture on the temporal muscle fascia. Even if a nerve gap defect was created, the proximal and distal cut ends were placed on the temporal muscle fascia almost in the original position without nerve graft. During the second stage surgery of middle ear cholesteatoma, regenerated nerve was detected in submucosal layer of the reconstructed eardrum. Incidence of regenerated chorda tympani nerve was 46% (33/71 cases).2. Functional result using electrogustometry and filter-paper disk method after severance of the nerveIn 33 cases with regenerated chorda tympani nerve, 61% (20/33 cases) had taste function. In other 87 cases whose chorda tympani nerves were severed during middle ear surgery, 24% (21/87 cases) showed recovery of taste function in eather electrogutometry or filter-paper disk method … More .3. Morphological study of fungiform papillae (distribution and size)In cases in which regeneration of the chorda tympani nerve was detected during the second stage of the surgery and taste function recovered, distribution and size of the fungiform papillae were observed using digital microscopy and their morphology was recorded in memory card. Distribution of the fungiform papillae was divided into three groups. (1)There was no difference in distribution of papillae between both sides on the tongue. (2)There is a difference in distribution between both sides. (3)The fungiform papillae was completely degenerated on the severed side of the tongue. In 35 cases whose taste function recovered after severance of the nerve, 31% was included in group 1 and 69% was in group 2. On the other hand, in 87 cases in which taste function did not recover, 61% was included in group 2 and 39% was in group 3.These results indicate that, after severance of the chorda tympani nerve, the chorda tympani nerve regenerate in the middle ear and these regenerated nerve fibers reach to fungiform papillae and re-obtained taste function. Less