大型听神经瘤显微切除术中应用IFNM技术可视化面神经

目的探讨术中面神经监测(IFNM)技术在显微切除大型听神经瘤过程中保留面神经的效果。方法对86例单侧大型听神经瘤(直径≥3cm)病人采用枕下乙状窦后入路显微切除肿瘤。切开肿瘤背侧包膜前,根据电刺激肿瘤表面及边缘产生的激发性肌电图来探查并确认面神经的行走路径;术中采用自发性肌电图监测面神经,使其免受牵拉、挤压或损伤,交替采用激发性肌电图实时探查、确认面神经,从而在虚拟状态下达到面神经"可视化"。结果本组肿瘤全切除79例,占91.9%;次全切除5例,占5.8%;大部分切除2例,占2.3%。面神经解剖保留74例,保留率达86.0%;实用听力保留28例,占32.6%。术后面神经功能House-Brackman分级:Ⅰ～Ⅱ级64例,占74.4%;Ⅲ～Ⅳ级15例,占17.4%;Ⅴ～Ⅵ级7例,占8.2%。结论采用IFNM技术术中"可视化"面神经是大型听神经瘤切除术后面神经得以保留的关键,而娴熟的显微手术技巧、扎实的桥小脑角局部解剖知识是手术成功的保障。     

面肌诱发电位在巨大听神经瘤术中面神经保护的研究及预后分析

目的 探讨经头皮颅骨刺激面肌诱发电位（TCeMEP）在巨大听神经瘤切除术中的面神经保护作用。方法 对28例巨大听神经瘤术中监测TCeMEP．并比较其变化和术后面肌功能的关系。结果 16例术后TCeMEP下降大于75％，其中9例明显面瘫，7例轻度面瘫；12例术后TCeMEP下降小于75％，其中2例明显面瘫，7例轻度面瘫，3例基本正常。两组明显面瘫率经x^2检验，P〈0．05。结论 TCeMEP可以术中实时监测全部面肌传导通路的功能．为术中保护面神经功能提供可靠的电传导依据。TCeMEP波幅下降75％可以作为术后可能发生明显面瘫的警戒点。     

听神经瘤术后面神经损伤的临床分类、分级研究

目的研究听神经瘤术后面神经颅内段损伤的分类、程度及临床分级。方法分析病理诊断明确的165例听神经瘤病例,肿瘤大小1.5~5.5 cm,术前面神经功能障碍19例。术中面神经损伤程度按Sunderland五级分类法分为Ⅰ级85例,Ⅱ级37例,Ⅲ级21例,Ⅳ级9例,Ⅴ级13例。结果随访1~3年,面神经功能House-BrackmannⅠ级88例,Ⅱ级12例,Ⅲ级20例,Ⅳ级9例,Ⅴ级3例,Ⅵ级33例。结论临床分级研究有助于量化面神经损伤的程度,提高对面神经损伤程度的认识,判断预后,评价手术效果。     

大型听神经瘤显微手术切除及面听神经保留技巧

目的 介绍大型听神经瘤显微手术切除及面听神经保留技巧。方法 对51例大型听神经瘤采用乙状窦后入路显微手术切除。结果 所有51例病人均行肿瘤全切,面神经解剖保留率为96％。根据House-Brackmann面神经功能分级标准,20例（39％）术后3个月内面神经功能为Ⅰ-Ⅱ级,27例（53％）为Ⅲ－Ⅳ级,4例（8％）为Ⅴ－Ⅵ级。根据Gardener-Robertson听力分级标准,3例（6％）听力保留。无手术死亡、脑干和后组颅神经损害及其他严重并发症。结论 采用显微手术技术,绝大多数大型听神经瘤均可以在保留面神经解剖完整的前提下手术全切。     

听神经瘤手术涉及的面神经段显微解剖及临床意义

目的探讨听神经瘤涉及的面神经段显微解剖．为听神经瘤手术提供解剖学数据。方法采用10％甲醛溶液充分同定的成人尸头标本15例，对面神经的脑干端、桥小脑角段、内耳道段及其毗邻结构进行测量和拍摄。结果面神经脑干端与周同解剖结构有恒定距离；桥小脑角段由面神经运动根、中间神经组成，与前庭蜗神经走行关系恒定；内耳道段面神经运动根在位听神经前上方．中间神经和面神经运动根在内耳道中部合成一干，面神经在内耳道底的横嵴上垂直嵴前走行：迷路段是面神经在颞骨内最短、最细的部分。结论研究听神经瘤涉及的面神经段显微解剖，有助于听神经瘤的切除，保护面神经。     

Electrophysiological characterization of pre- and postoperative facial nerve function in patients with acoustic neuroma using electrical and magnetic stimulation techniques

Facial nerve function was examined in patients who underwent posterior fossa surgery for unilateral acoustic neuroma. Examinations took place prior to surgery (n = 47 patients), early after surgery (0–12 days, n = 16 of 47 patients), and late after surgery (187–1505 days, n = 29 of 47 patients). Clinical signs of facial palsy were present to a variable extent in 13 of 47 patients before, in 12 of 16 patients early, and in 18 of 29 patients later after surgery. Electrophysiologically, the facial nerve was stimulated electrically at the stylomastoid fossa and magnetically at its proximal intracanalicular segment. In addition, the faceassociated motor cortex was stimulated magnetically. In patients with facial palsy, any of these stimulation methods resulted in a decreased amplitude of the response in the nasalis muscle. The decrease showed a linear relationship to the clinical grade of palsy, pre- and postoperatively. Corticomuscular latencies remained unchanged. We conclude that: (i) the electrophysiological characteristics of facial nerve lesions due to compression by acoustic neuromas or due to a complication of neuroma removal are those of a purely axonal neuropathy; (ii) the three stimulation techniques have a similar diagnostic yield, thus making the use of all three of them redundant; and (iii) the electrophysiological techniques allowed no prediction of the final facial nerve function. © 1994 John Wiley & Sons, Inc.     

听神经瘤的锁孔手术治疗

目的探讨听神经瘤的微创手术治疗。方法对35例听神经瘤病人采用枕下乳突后锁孔入路开颅进行显微外科手术治疗。肿瘤最大径2.3~5.6 cm。手术骨窗大小为3.0 cm ×2.5 cm,暴露横窦与乙状窦交汇处。对小于3 cm的肿瘤先磨开内听道,切除内听道内肿瘤并分离出内听道端面神经及耳蜗神经后,逐步切除颅内肿瘤;对超过3 cm的肿瘤先分块切除颅内肿瘤,找到脑桥端面神经后再逐步将面神经从肿瘤上分离,最后磨开内听道,切除其内肿瘤。术中均行面神经监护。结果肿瘤均获得全切除。面神经解剖保存率为100%,7例(20.0%)保留耳蜗神经。术后1周House-Brackmann分级Ⅳ级者17例,Ⅲ级12例,Ⅱ级6例;术后3个月随访,House-Brackmann分级Ⅳ级3例,Ⅲ级19例,Ⅱ级11例,Ⅰ级2例。结论运用显微外科技术,采用锁孔外科手术治疗听神经瘤,不仅能有效地对肿瘤实施全切除,而且可大大减少手术创伤。     

桥小脑角区肿瘤术中面神经功能监护

目的总结桥小脑角区肿瘤术中面神经功能的电生理监测经验。方法对48例桥小脑角区肿瘤病人术中应用肌电图进行连续实时监护，同时进行脑于听觉诱发电位监测，结果术中当接近、触及、牵拉、刺激面神经时，自发肌电图出现突发、双相或多相的高幅电位改变，面神经得以准确定位。脑干听觉诱发电位各波变化中以Ⅴ波潜伏期延长及波幅降低最为显著。肿瘤全切除45例．面神经解剖保留44例，功能保留38例，术后2周House—Brackmann面神经功能分级：Ⅰ-Ⅱ级38例，Ⅲ～Ⅳ级8例，Ⅴ级2例；其中Ⅰ～Ⅱ级的术中刺激值为0．1～0．2mA。尢死亡及长期昏迷病例。结论突发的双相或多相的高幅肌电图改变，及脑干听觉诱发电位示Ⅴ波潜伏期延长和波幅下降，均为敏感的变化指标：桥小脑角区肿瘤术中实施监护．有助于提高面神经的功能保留率。     

大型听神经瘤的术中面神经保护（附38例分析）

目的总结显微外科技术与电生理监测技术在大型听神经瘤显微切除术中的经验。方法回顾性分析38例大型听神经瘤的临床资料。术前面神经功能House—Brackrnann分级（H—B分级）：Ⅰ～Ⅱ级36例,Ⅲ～Ⅳ级2例。结果肿瘤全切除33例,次全切除5例;术中面神经解剖保留32例,术后死亡1例。出院时面神经功能H—B分级：Ⅰ～Ⅱ级28例,Ⅲ-Ⅳ级6例,Ⅴ-Ⅵ级3例。结论应用显微外科技术与电生理监测技术可明显提高大型听神经瘤显微切除术的疗效。严格保持肿瘤表面蛛网膜的完整性是保留面神经功能的关键。术中尽量重建断裂的面神经,对术后神经功能恢复有一定帮助。     

Comparative study of evoked electromyography and facial nerve latency test in the prognosis of idiopathic facial nerve palsy in childhood

We report our results from the application of evoked electromyography (EEMG) and facial nerve latency testing (FNLT) in 30 children aged 4–14 years with idiopathic facial palsy. Our aim was to define the value of these tests as prognostic tools in Bell's palsy. From the EEMG results we ascertained that, when the amplitude of the compound muscle action potential varied between 51% and 95% of the normal value, the neuronal damage is slight (neurapraxia). When the percentage value of muscle response decreases, the prognosis is worse. The results of the FNLT showed that, when the latency is within normal limits, the damage to the nerve is slight (neurapraxia). If the latency is prolonged, the prognosis is worse. Evaluation of our results and comparison with the index of facial nerve functional recovery showed that those two tests have a high percentage of correctness (100% for the EEMG and 96.7% for the FNLT) and a low percentage of error. We conclude that these tests are excellent for predicting the outcome of facial nerve palsy in childhood and we suggest that young patents undergo both so that the determination of the lesion may be as correct as possible.