耳神经外科术中神经监测

术中利用肌电图(electromyography,EMG)监测面神经最早应用于颅内手术是1979年[1]。在此以前,监测面神经术中是否受损或受到刺激多采用直接观察面部运动或使用特制小铃缝在病人面部皮肤,若发生面肌收缩则带动小铃,通过听铃声的办法来“监测”面神经。术中耳蜗神经监测最早应用于桥脑小脑角手术是1980年[2]。目前术中面神经监测已常规应用于听神经瘤手术和其它桥脑小脑角手术,直接听神经动作电位和听性脑干电位监测也逐步被耳神经外科医师广泛接受。     

BAEP在耳神经外科术中监测的应用

脑干听觉诱发电位（brainstem auditoyry evoked potentials,BAEP)等电生理技术中监测是耳神经外科应用最早、最广泛的监测技术，它可以通过早期发现听神经的电位变化，术中最大限度地避免或减轻听神经损伤，并对术后听力进行预测评估。本文对其在耳神经外科中监测的应用情况作一综述。     

听神经瘤手术中的面神经功能保护

听神经瘤手术中的面神经功能保护周梁，金西铭由于耳显微外科和耳神经外科的发展，听神经瘤手术在完全切除肿瘤的基础上保留面神经功能已成为耳神经外科医生关注的重要课题。我科１９９１年２月～１９９３年８月间手术治疗听神经瘤７例，其中男２例，女５例。左侧１例，右...     

BAEP在耳神经外科术中监测中的应用

脑干听觉诱发电位 (brainstem auditory evoked potentials,BAEP)等电生理技术术中监测是耳神经外科应用最早、最广泛的监测技术 ,它可以通过早期发现听神经的电位变化 ,术中最大限度地避免或减轻听神经损伤 ,并对术后听力进行预测评估。本文对其在耳神经外科术中监测的应用情况作一综述。     

173 BAEP在耳神经外科术中监测的应用

脑干听觉诱发电位(brainstem auditory evoked potentials,BAEP)等电生理技术术中监测是耳神经外科应用最早、最广泛的监测技术,它可以通过早期发现听神经的电位变化,术中最大限度地避免或减轻听神经损伤,并对术后听力进行预测评估.本文对其在耳神经外科术中监测的应用情况作一综述.     

畸变产物耳声发射用于耳神经外科手术中听觉监测的实验研究

目的:探讨畸变产物耳声发射(DPOAE)用于耳神经外科手术中听觉监测的可行性。方法:将24只纯种新西兰大白兔随机等分为3组,分别观察无手术、暴露桥脑小脑角后下压小脑、暴露面听神经复合体后阻断内听动脉血流5min共3种状态下的DPOAE值,并行组织学检查。结果:下压小脑、阻断内听动脉血流后均记录到DPOAE发生改变,部分频率未引出,引出频率的DPOAE值降低,与术前比较差异有统计学意义(P<0.05),并与组织学变化相符。结论:DPOAE能有效监控耳神经外科手术中的听损伤,具有较好的临床应用前景。     

内耳血供阻断对听觉影响的实验观察

以兔为实验对象，模拟耳神经外科手术暴露小脑桥脑角的过程，观察内耳血供阻断不同时间与听觉损伤的关系，为提高耳神经外科手术的听觉保留效果提供借鉴。     

听神经瘤术中连续听力监测的初步探讨

目的探讨听神经瘤外科术中连续听力监测的意义。方法采用乙状窦人路，在听性脑干反应（auditory brainstem response，ABR）和耳蜗电图（electrocochleogram，ECochG）监测下完成的听神经瘤切除术10例。对手术过程和术后听力结合术中监测进行分析。结果10例听神经瘤术前听力A级3耳，B级4耳，C级3耳（美国耳鼻咽喉头颈外科学会分级标准）。术前的ABR检查Ⅰ、Ⅲ、Ⅴ波存在者5耳（A级3耳，B级2耳），仅见Ⅰ波者5耳（B级2耳，C级3耳）。麻醉后手术前的监测显示：Ⅰ、Ⅲ、Ⅴ波存在者2耳，仅Ⅰ波存在者6耳，以复合动作电位（compound action potential，CAP）的N1波代替波Ⅰ；无波形者2耳。术后听力保留2耳，肿瘤均〈2cm，术前听力都为A级；连续听力监测显示1耳术中及术毕时Ⅰ、Ⅲ、Ⅴ持续存在，1耳Ⅰ、Ⅲ波存在，Ⅴ波消失；术后听力均为A级。听力未保留8耳，其中6耳术中监测时仅CAP的N1（波Ⅰ）存在，手术过程中夹内听动脉或处理内耳道处肿瘤时，4耳CAP波幅明显下降，甚至下降至0，术毕又恢复至术前的50％～60％或正常；1耳蜗神经与肿瘤一并切除，但CAP始终存在；1耳因牵拉脑干侧的耳蜗神经，CAP波幅降至0，手术结束亦未恢复。2耳为全身麻醉后术前监测中未引出任何波形者，其中1耳术中切除部分肿瘤后，出现CAP波，但波幅低，直至术毕；1耳始终未出现波形。结论联合应用ABR和ECochG术中监测，对提高听力保护率有积极意义，能及时反映术中与保留听力相关的敏感手术步骤，然而外科医师的熟练的解剖和精确的手术技巧是手术成功的最基本因素。     

内窥镜耳科手术

在耳鼻咽喉科采用硬管内窥镜进行损伤极轻微的具窦手术已受到极大关注。耳科和耳神经外科采用硬管内窥镜替代开放性手术较晚，近年来文献报道已增多。本文回顾了采用硬管内窥镜技术进行各种耳科及耳神经外科手术，包括中耳探查术，慢性耳病手术，二期乳实根治术，听神经瘤手术和前庭神经切断术。诊室中耳探查术：目前可在诊室内用中耳内窥镜进行中耳探查术。用中耳内窥镜的激光鼓膜切开术（LAT）操作使得能够用硬管内窥镜直接检查中耳。首先用地卡因溶液（160mg粉末溶解在0．2ml异丙醛乙醇内）作鼓膜局部麻醉8分钟，麻醉可持续2小时。CO。…     

乙状窦后径路听神经瘤切除术中内镜辅助应用价值的探讨

目的：探讨内镜辅助在行乙状窦后径路听神经瘤切除术中的应用和意义。方法：在内镜辅助下经乙状窦后径路听神经瘤切除术12例,术中行面、听神经监测,手术前后面听功能评估,并与未采用内镜辅助的乙状窦后径路手术进行综合比较。结果：12例听神经瘤完全切除,手术完成顺利,术后无并发症。术中面听神经均获解剖保留,术中神经监测以观测面听神经功能保留情况,术后半年面神经功能与术前相比无明显改变,所有患者听觉功能与术前相比均有不同程度下降。内镜辅助下手术组术后面神经功能及听觉功能改变与未采用内镜辅助手术组差异无统计学意义。结论：在乙状窦后径路手术中应用内镜辅助能为桥小脑角区手术提供精确的信息,在避免后半规管、颈静脉球损伤的前提下,完全切除内耳道底的肿瘤,减少并发症的发生,但对面听神经功能保留无明显作用。     

Acoustic neuroma surgery: use of cochlear nerve action potential monitoring for hearing preservation

OBJECTIVES: To compare the hearing preservation results obtained with use of two intraoperative eighth nerve monitoring methods, cochlear nerve action potential (CNAP) and auditory brainstem response (ABR), during complete acoustic neuroma (AN) resection. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS: Thirty-three consecutive patients who underwent hearing preservation AN surgery. INTERVENTIONS: Intraoperative monitoring by CNAP and/or ABR during AN resection. MAIN OUTCOME MEASURE: Postoperative hearing. Hearing preservation was considered achieved for pure-tone average < or =50 dB and speech discrimination > or =50%. RESULTS: Thirty-two patients met inclusion criteria for the study. Monitoring was successfully performed in 23 of 25 patients (92%) who underwent attempted CNAP monitoring and 13 of 27 (48%) who underwent attempted ABR monitoring. When tumor size was < or =20 mm in greatest dimension, hearing preservation was achieved in 12 of 18 patients (67%) monitored with CNAP, versus 2 of 8 patients (25%) not monitored with CNAP (p = 0.05). Monitoring by ABR did not improve hearing preservation rates compared with those not monitored with ABR (40% vs. 63%). At the completion of surgery, the presence or absence of CNAP predicted the presence or absence of hearing preservation in 18 of 23 cases (p = 0.01), while ABR successfully predicted hearing results in 10 of 13 cases (p = 0.05). CONCLUSIONS: When CNAP and ABR monitoring techniques during AN surgery were compared, CNAP was more frequently obtainable. Monitoring by CNAP was significantly associated with a higher chance of hearing preservation. Monitoring by ABR did not have a positive influence on hearing preservation results. Both ABR and CNAP were useful for predicting postoperative hearing.     

Acoustic neuroma surgery: absent auditory brainstem response does not contraindicate attempted hearing preservation.

OBJECTIVE: Absence of auditory brainstem response (ABR) waveforms has been associated with a poor likelihood of hearing preservation following resection of acoustic neuromas. Our experience is reviewed for patients with absent preoperative ABR regarding hearing preservation, hearing improvement, and return of ABR. STUDY DESIGN: Retrospective review of 22 cases of acoustic neuroma resection. Nine patients with absent preoperative ABR were identified. All underwent tumor resection utilizing intraoperative cochlear nerve action potential (CNAP) monitoring. Postoperative hearing results and ABR waveforms were examined. METHODS: Charts were reviewed and tabulated for age, sex, tumor side, tumor size, preoperative and postoperative audiometric and ABR results, intraoperative monitoring results by ABR and CNAP, and surgical complications. RESULTS: Hearing preservation was achieved in seven of nine patients (78%) with absent preoperative ABR, as well as six of seven patients (86%) with tumors less than or equal to 20 mm in greatest dimension. Although intraoperative ABR monitoring was not possible in any of these patients, CNAP monitoring was successful in all. Return of ABR waveforms was observed in four of the six patients (67%) tested from 3 to 22 months postoperatively. Four of the seven patients (57%) enjoyed improvement in hearing class as defined by the guidelines of the American Academy of Otolaryngology-Head and Neck Surgery. CONCLUSIONS: Absent ABR waveforms have not been a negative prognostic sign regarding hearing preservation. CNAP monitoring is possible in these patients and likely helps to minimize iatrogenic cochlear nerve trauma. Patients with no ABR waveforms have hope of hearing preservation and even improvement following acoustic neuroma resection performed utilizing CNAP monitoring and hearing preservation surgical techniques.     

两种听觉监护在听神经瘤术中的联合应用及评价

目的　探讨听神经瘤手术中听觉监护的意义。比较听性脑干反应（ABR）和蜗神经动作电位（cochlear nerve action potential,CNAP）在听觉监护应用中的价值。方法　回顾性分析我中心12例保留听力手术的听神经瘤患者资料及术中情况,患者术前均有实用听力（AAO-HNS分级A级、B级）,可引出ABR波形,V波分化可,所有手术均采取乙状窦后径路摘除肿瘤。所有患者均全程ABR监护,术中打开脑膜后联合监测CNAP。结果　手术过程中所有患者ABR波形较术前基线均有不同程度的变化,可记录到V波潜伏期均较基线延长（0.68±0.41）ms。CNAP波幅个体差异性较大,可记录到的P1潜伏期均较基线延长（0.25±0.16）ms。12例中有8例（66.7%）患者术后保留可用听力;另外4例（33.3%）术后达不到可用听力,此4例患者ABR表现为3例V波消失,1例V波潜伏期延长。CNAP表现为2例CNAP的P1消失,2例P1延长。电钻钻磨造成的震动和噪声、手术时神经被牵拉或热损伤后等急性损伤后ABR和CNAP波幅均出现短时间急剧下降,手术暂停5 min后,部分患者波幅可在一定程度恢复。结论　听神经瘤手术中ABR和CNAP对于听觉监护均有一定意义。ABR波形稳定可靠,但叠加时间相对较长;CNAP叠加快速,可提升监测灵敏度,但波形变异度较大。电钻钻磨造成的震动和噪声、操作过程中对神经组织的牵拉以及热损伤均被及时监控,两者联合应用可提升听神经瘤手术的听觉功能保留率。     

Intraoperative monitoring of early auditory evoked potentials in hearing acoustic neuroma patients complemented by cochlear nerve action potentials]

Hearing preservation was attempted in eight cases of acoustic neurinomas with good preoperative hearing. This was successful in 3 cases. Brain-stem auditory evoked potentials (BAEP0 were monitored in all cases, and compound nerve action potentials (CNAP) were recorded from the cochlear nerve in the last 3 cases. The BAEP was extremely sensitive to intraoperative manipulation. Intraoperative loss of wave V in BAEP was observed not only in all 5 cases with postoperative hearing loss, but also in 2 out of 3 cases with successful hearing preservation. CNAP correlated better with the hearing outcome than BAEP. In the cases where hearing was preserved, intact CNAP responses were demonstrated at the end of the operation. Conversely, deterioration of CNAP was seen in a case of postoperative hearing loss. CNAP was 10-15 times larger in amplitude than BAEP, so that the new responses were obtainable in shorter intervals. This capability of frequent examination seemed to increase the possibility of avoiding irreversible damage to the hearing by changing surgical tactics. The addition of CNAP monitoring is a good supplement to conventional BAEP monitoring in acoustic neurinoma surgery.     

听性脑干反应和蜗神经直接动作电位联合听觉监护在侧颅底手术中的应用

目的:通过听性脑干反应(ABR)和蜗神经动作电位(CNAP)在侧颅底外科手术中的应用,分析造成听力损伤的原因,并对这两种听觉监测技术作出评价。方法:在手术过程中对14例保留听力的侧颅底手术的患者进行听觉监测。ABR在整个手术过程中监测,CNAP在打开脑膜、暴露蜗神经后进行监测。在患者出院后1个月左右随访听力。结果:所有患者在手术过程中都有不同程度的ABR变化,尤其是耳科电钻使用后[相对使用前延长(0.19±0.16)ms)]和颅内操作时[相对操作前延长(0.29±0.25)ms]。部分患者的波形潜伏期延长在术毕时有所恢复[10例,平均缩短(0.27±0.16)ms]。结论:侧颅底手术中应用听觉监护能防止听觉损伤。电钻使用造成的震动和噪声对听力有损伤,解除引起波形潜伏期延长的诱因后可恢复部分听力。术后的听力预后与术毕潜伏期的延长有相对应关系。术中监测的新趋势是联合应用ABR和CNAP,取长补短。     

Evaluation of three intraoperative auditory monitoring techniques in acoustic neuroma surgery

OBJECTIVE: To assess the efficacy of three intraoperative auditory monitoring techniques: auditory brainstem response (ABR), electrocochleography (ECoG), and direct eight nerve monitoring (DENM). STUDY DESIGN: A retrospective review of the intraoperative recordings of ABR, ECoG, and DENM was performed. SETTING: A private, neurotologic practice. PATIENTS: Sixty-six patients with usable preoperative hearing underwent intraoperative auditory monitoring with ABR, ECoG, or DENM. INTERVENTIONS: Intraoperative auditory monitoring. MAIN OUTCOME MEASURES: Postoperative pure-tone hearing threshold and word recognition scores. RESULTS: Of the 66 patients, 16 (24%) had postoperative serviceable hearing. Five (18%) of the 28 with ABR monitoring, 3 (17%) of the 18 with ECoG monitoring, and 8 (40%) of the 20 with DENM monitoring had serviceable hearing after surgery. CONCLUSIONS: This study suggests that DENM may be more effective than ABR or ECoG, although the differences in hearing preservation rates are not statistically significant.     

听神经瘤术中听力监测及术后听力保留影响因素分析

目的探讨听神经瘤术中听力监测的应用及术后听力保留的可能影响因素。方法16例采用乙状窦后入路手术切除听神经瘤的成年患者,分为两组,术中采用听性脑干反应(auditory brainstem response,ABR)和耳蜗电图(electrocochleogram,ECochG)联合监测为监测组(8例),未监测者为未监测组(8例),比较两组患者术后听力保留情况,采用单因素分析,分析影响听力保留的可能因素,包括:年龄、病程、肿瘤大小、术前纯音听阈和言语识别率、术中是否行ABR和ECochG联合监测、内听道是否扩大、肿瘤和神经是否粘连等。结果前庭诱发肌源性电位(VEMP)提示16例患者肿瘤来源于前庭上神经,监测组中6例术中及术毕ABR波Ⅰ、Ⅴ和复合动作电位(CAP)持续存在,术后听力保留;1例术中ABR波Ⅰ、Ⅴ和ECochG CAP持续存在,但术后无可用听力;1例术中切除肿瘤时ECochG与基线重复性良好,ABR波V消失,手术结束波V仍未恢复;监测组术后听力保留率为75.0%(6/8),未监测组术后无一例保留听力,差异有统计学意义(P=0.007)。单因素分析显示,年龄、病程、肿瘤大小、术前纯音听阈以及内听道扩大与术后听力保留率无关(P>0.05),术前言语识别率、术中ABR和ECochG联合监测、肿瘤和神经粘连与否与术后听力保留率相关(P<0.05)。结论听神经瘤切除术中ABR和ECochG连续监测对指导手术和提高术后听力保留率有重要意义,肿瘤与神经粘连是术后听力保留的重要影响因素,手术技巧、术前听力、肿瘤大小、内听道扩大等是否是术后听力保留的影响因素需扩大样本进一步研究验证。     

The efficacy of brainstem auditory evoked potentials in acoustic tumor surgery

As the identification of patients with small acoustic neuromas and salvageable hearing increases, intraoperative auditory nerve monitoring has been used increasingly in an attempt to improve the hearing preservation rate. Far-field recordings obtained by brainstem auditory evoked potentials (BAEP), at times enhanced by electrocochleography, have become a standard method of intraoperative auditory nerve assessment. To evaluate the usefulness of this monitoring technique, the hearing preservation results of a series of unmonitored acoustic tumor removals were compared to a series of patients monitored via the standard brainstem auditory evoked potentials. With comparable average tumor sizes, 4 of 7 unmonitored patients had hearing preserved at preoperative levels compared to 4 of 9 monitored patients. Neither preoperative BAEP assessments nor absolute tumor size were predictive of hearing preservation. This report brings into question the effectiveness of far-field intraoperative BAEP monitoring during acoustic tumor resection and suggests that direct auditory nerve monitoring may be more appropriate.     

Association between surgical steps and intraoperative auditory brainstem response and electrocochleography waveforms during hearing preservation vestibular schwannoma surgery

Intraoperative monitoring of the auditory pathway by means of either electrocochleography or auditory brainstem response audiometry is valuable during hearing preservation vestibular schwannoma (VS) surgery. A more than 75% intraoperative reduction of the amplitude of these evoked auditory potentials was thought to be related with clear hearing compromise of hearing. We identified 22 patients who satisfied this intraoperative criterion in a cohort of 86 consecutive patients who had attempted hearing preservation VS surgery. The surgical step that temporally coincided with the above event was considered to be the most critical step for hearing monitoring during this kind of surgery. Most frequently, drilling of the internal auditory canal and direct tumor resection were associated with the aforementioned changes, but also drilling of the cortical temporal bone at the very beginning of surgery or the opening of the dura could be implicated. This profound intraoperative amplitude decrease was associated with a profound postoperative hearing impairment in 84% of the cases.