Pirsig W, Kida A
Laryngol Rhinol Otol (Stuttg). 1977 Jan;56(1):50-6.
Chorda tympani nerve specimens of 10 patients were studied by the light and electron microscope. The nerve specimens were obtained while performing stapedectomy in 7 patients, a tympanoplasty in two patients with otitis media chronica, and from one patient whodied 8 months after hemiglossectomy, neck-dissection and radiotherapy because of squamous cell carcinoma. The chorda tympani nerve is built up by few 10 to 12 micron thick and numerous 3 to 4 micron thick myelinated fibers in the semithick sections. The 10 to 12 micron axons are largely reduced in patients with chronic middle ear infection and in older patients. In persons with otosclerosis degenerative alterations of the axons and inclusions in the cytoplasm of the Schwann cells can be demonstrated similar to those of the diabetic, alcohol induced and ischemic neuropathy. In patients with chronic middle ear disease the degenerative changes mainly occur in the myelin sheats and in axoplasma finally leading to axolysis. A total degeneration and fibrous transformation of the chorda tympani nerve can be observed after hemiglossectomy. By means of morphological criteria afferent and efferent axons can not be distinguished in this material.
对10例患者的鼓索神经标本进行了光镜和电镜研究。7例患者在进行镫骨切除术时获取神经标本，2例慢性中耳炎患者在进行鼓室成形术时获取标本，1例因鳞状细胞癌行半舌切除术、颈部淋巴结清扫术及放疗8个月后死亡的患者提供了标本。在半厚切片中，鼓索神经由少数10至12微米厚的和许多3至4微米厚的有髓纤维组成。在慢性中耳感染患者和老年患者中，10至12微米的轴突大量减少。在耳硬化症患者中，可证明轴突有退行性改变以及施万细胞胞质内有包涵体，类似于糖尿病性、酒精性和缺血性神经病变。在慢性中耳疾病患者中，退行性改变主要发生在髓鞘和轴浆中，最终导致轴突溶解。半舌切除术后可观察到鼓索神经完全变性和纤维性转化。根据形态学标准，在此材料中无法区分传入和传出轴突。
