人工耳蜗植入者EABR与ECAP分析

目的探讨听觉电诱发电位对人工耳蜗植入者的电听觉传导功能客观评价的意义。方法对14例人工耳蜗植入者行电诱发听性脑干反应（electrically evoked audiotory brainstem responses,EABR）和电诱发听神经复合动作电位（electrically evoked compound action potential,ECAP）检查,根据第1、10、22号电极ECAP波形的检出与否将其分成A（1、10、22号电极ECAP均检出）、B（1、10、22号三个电极中有一个及以上ECAP未检出）两组,检测A组和B组患者的EABR阈值、波Ⅲ、Ⅴ潜伏期、Ⅲ-Ⅴ波间期并对其结果进行比较。结果刺激脉宽分别为25、50、75、100、125μs时,22号电极的EABR阈值B组高于A组,差异有显著统计学意义（P〈0.001）;刺激脉宽为50μs时：1号和10号电极的EABR阈值B组高于A组,差异有显著统计学意义（P〈0.001）。A、B两组患者22、10、1号电极EABR波Ⅲ、Ⅴ潜伏期和Ⅲ-Ⅴ波间期之间的差异无统计学意义（P〉0.05）。结论 ECAP波形较好者的EABR阈值较ECAP波形较差者的EABR阈值低。EABR波Ⅲ、Ⅴ潜伏期、Ⅲ-Ⅴ波间期与ECAP波形引出与否无明显相关性,ECAP灵敏性高而EABR稳定性好。     

大前庭水管综合征患者ABR和人工耳蜗术后EABR反应特征分析北大核心CSCD

目的探讨大前庭水管综合征(LVAS)患者的听性脑干反应(ABR)及人工耳蜗植入术后电诱发听性脑干反应(EABR)的特点,为LVAS患者人工耳蜗植入围手术期的电生理监测反应特征提供参考。方法选择2013年1月至2016年3月在我院行人工耳蜗植入的14例大前庭水管综合征患者。记录人工耳蜗植入前ABR反应阈值及潜伏期,观察声诱发短潜伏期负反应(ASNR)的表现,并统计该波的出现概率。记录患者术后EABR波形、V波阈值及III、V波潜伏期,计算III、V波引出率及EABR分级。比较ABR的V波和EABR的V波的潜伏期差异。比较ABR出现与不出现ASNR组的EABR反应阈值和V波潜伏期差异。结果 14例患者中有5例术前ABR可引出ASNR,9例无ASNR,V波潜伏期6.6～8.15ms。人工耳蜗植入后有13例引出有意义的EABR波形,平均EABR阈值为190.8CL,平均III波潜伏期为1.80ms,平均V波潜伏期为3.59ms,有1例EABR未引出反应。根据Gibson EABR分级标准,ASNR组与无ASNR组EABR波形分化无明显差异。ASNR组EABR阈值177.5CL,无AS-NR组阈值196.7CL,二者有统计学差异。ASNR组V波潜伏期4.71ms,无ASNR组V波潜伏期4.68ms,二者无统计学差异。EABR的V波潜伏期比ABR的V波潜伏期短,二者有统计学差异。结论 LVAS患者的ABR反应中出现ASNR波是其听力学特征性表现之一,但EABR记录不到相应的短潜伏期负反应。EABR的V波潜伏期较ABR短。植入前存在ASNR的大前庭水管综合征患者具有较低的植入后EABR反应阈。     

人工耳蜗植入术后NRT与EABR动态变化研究

目的观察人工耳蜗植入后短期神经反应遥测（neural response telemetry,NRT）、电诱发听性脑干反应（electrically auditory brainstem response EABR）的动态变化,探讨人工耳蜗植入术后神经传导通路的动态变化。方法：对12例极重度感音神经性聋患者分别于人工耳蜗植入术后1月（开机）及术后2月（开机1月）行NRT、EABR检测,观察NRT、EABR阈值及EABR波v潜伏期变化。结果：术后1月及术后2月NRT阈值无显著性差异（P〉0．05）;术后2月与术后1月相比,20号电极EABR阈值显著降低（P〈0．05）、EABR波V潜伏期显著缩短（P〈0．05）。10号、3号电极在两个不同时间点EABR阈值、EABR波V潜伏期均无显著性差异（P〈0．05）.结论：人工耳蜗植入术后短期内,NRT阈值变化不明显,而EABR阈值、波V潜伏期在发生变化,提示人工耳蜗术后患者的听觉神经传导通路具有动态变化趋势。     

电诱发听性脑干反应在人工耳蜗植入中的应用

目的分析人工耳蜗植入患者耳蜗植入前电诱发听性脑干反应（electrical auditory brainstem response,EABR）的测试结果并初步探讨其意义。方法对14例不同病因、不同年龄的人工耳蜗植入患者耳蜗植入前进行测试,采用EMG外置电刺激器连接面神经探针作为刺激电极,采用Neuro Soft公司生产的Neruo Audio听觉诱发电位仪及调试软件进行EABR测试,测量并分析EABR波形,各波潜伏期和波间期,Ⅴ波波幅、阈值。结果EABR的Ⅱ、Ⅲ、Ⅳ、Ⅴ波与声诱发ABR相似,Ⅲ、Ⅴ波的潜伏期较声诱发ABR缩短,但Ⅲ~Ⅴ波间期与声诱发ABR相同。14例耳聋患者均记录到EABR的Ⅲ波/Ⅴ波,引出率为100％。4例极重度感音神经性聋未合并其他异常患者术中2.5、2.0 mA刺激Ⅲ、Ⅴ波典型,潜伏期和波间期均正常,术中神经反应遥测技术（neural response telemetru,NRT）引出,提示其听神经脑干传导通路无异常,预后效果良好。其他部分患者存在潜伏期延长或波形分化不良或刺激阈值较高等表现,提示可能由于不同因素所导致听觉传导通路异常。结论EABR是通过电刺激耳蜗来了解听觉系统对电刺激的生理反应,最接近人工耳蜗的工作状态,可以对患者听力康复的效果提供更准确的预测;特别是对于一些特殊患者,具有评估人工耳蜗植入效果的优势。而对各种特殊类型耳聋的人工耳蜗植入术前检测、术后评估数据仍需深入探索。     

人工耳蜗植入后EABR动态变化的初步研究

目的观察人工耳蜗植入儿童电诱发听性脑干反应(electrically auditory evoked response EABR)的动态变化,了解慢性电刺激后听觉通路反映特性的变化,为听觉系统的可塑性变化研究提供实验依据。方法本研究采用前瞻性设计,对19例平均年龄为3.2±1.0岁的语前聋儿童在接受人工耳蜗植入术中电极植入后进行EABR检测,患者在人工耳蜗植入后5.4±3.2月后再次进行EABR检测,观察EABR阈值、波III、波V潜伏期以及EABR输入输出曲线指标的变化。结果EABR平均阈值从人工耳蜗植入术中的196.9±11.1CL下降到术后5.4±3.2个月的189.2±13.2CL CL,配对t检验显示显著性差异（p=0.006）。平均阈上20CL V波潜伏期从人工耳蜗植入术中的4.72±0.21ms缩短到术后5.4±3.2月的4.60±0.18ms,配对t检验显示显著性差异（p=0.032）。结论耳聋儿童在接受人工耳蜗电刺激后EABR的反应阈值和潜伏期变化在最初的5.4±3.2月已经出现,提示3岁左右年龄段儿童听觉系统具有较好的可塑性,人工耳蜗植入后早期的听觉、言语训练尤为重要。     

正常耳与聋耳电诱发听性脑干反应实验动物的研究

目的 通过耳蜗外电刺激探讨正常听力与致聋家猫耳蜗EABR检测效果的差异性.方法 选取听力正常家猫,行蜗外EABR检测,刺激电极置于圆窗龛6点和12点方向,分别记录EABR;联合应用卡那霉素和利尿酸钠制备重度耳聋实验动物模型,行蜗外圆窗龛6点方向的EABR检测,比较不同耳蜗外位点及致聋前后EABR的差异.结果 圆窗龛6点方向时EABR阈值为529+27μA,Ⅲ波及Ⅳ波潜伏期为2.16+0.12ms,2.91+0.14ms,12点方向时阈值为545+44μA,Ⅲ波及Ⅳ波潜伏期为2.18±0.13ms,2.93±0.10ms,两者无统计学差异(P＞0.05);致聋前EABR阈值为525+23μA,Ⅲ波及Ⅳ波潜伏期为2.16±0.11ms,2.89±0.14ms,致聋后EABR阈值为558+37μA,Ⅲ波及Ⅳ波潜伏期为2.17±0.09ms,2.91±0.12ms,致聋前后阈值及波潜伏期相比均无统计学差异.结论 刺激电极位点位于圆窗龛6点和12点方向时,EABR阈值及Ⅲ、Ⅳ波潜伏期无统计学差异,但6点方向时波形更容易引出;聋耳EABR波形形态与正常耳EABR形态相似,致聋前与致聋后EABR阈值、Ⅲ波及Ⅳ波潜伏期相比均无统计学差异.     

不同脉宽条件下人工耳蜗植入者术中 电诱发听性脑干反应检测的特点分析

摘要：目的比较不同脉宽条件下人工耳蜗植入者术中电诱发听性脑干反应（electrically evoked auditory brainstem response,EABR）的特点,分析脉宽与EABR波V引出率和阈值之间的关系,总结不同脉宽条件对EABR波V引出率和阈值的影响,选择更优化的EABR脉宽测试参数。方法无残余听力的人工耳蜗植入患者24例作为实验组,其中耳蜗形态正常12例、大前庭导水管综合征（large vestibular aqueduct syndrome,LVAS）4例、Mondini畸形4例、共同腔畸形（common cavity deformation,CCD）2例、内听道狭窄2例;筛选条件相近的24例有残余听力的人工耳蜗植入者配对作为对照组。应用改装的Cochlear Freedom人工耳蜗及自制的铂铱合金球电极对拟行人工耳蜗植入的两组者术中分别给予50、100、200 μs不同脉宽的电刺激,Bio logic Navigator Pro听觉诱发电位仪记录不同脉宽条件下EABR波V引出率和阈值。结果脉宽50、100、200 μs时,EABR波V引出率实验组（均为91.7%）低于对照组（分别为100%、100%、95.8%）,差异无统计学意义（P均>0.05）;而EABR阈值实验组［分别为(183.73±8.96)CL、(151.28±10.05)CL、(120.56±12.82)CL］高于对照组［分别为(175.50±9.14)CL、(142.71±11.45)CL、(110.63±10.24)CL］,差异均具有统计学意义(t值分别为18.87、16.82、17.64,P均<0.05)。结论蜗内单极刺激能诱发出良好的EABR波形,无残余听力的患者EABR阈值要明显高于有残余听力的患者。相对于脉宽200 μs,50、100 μs时EABR波形波V引出率高;脉宽50 μs波形分化更好、动态范围广,内耳畸形严重可能需要适当加大刺激量（如将脉宽改为100 μs）。     

人工耳蜗植入者电诱发听性脑干反应阈值与行为测听阈值相关性研究

目的　通过对人工耳蜗植入者行为测听阈值和电诱发听性脑干反应（electrical evoked auditory brainstem response，EABR）阈值相关性比较，探讨用EABR波Ⅴ阈值 进行术后调试的可行性。方法　对19例（20耳）人工耳蜗植入者分别选取第1、6、11、16、22号刺激电极行EABR和行为测听测试，获得阈值。结果　刺激电极EABR波Ⅴ潜伏期为（3.73±0.37）ms；第1、6、11、16、22号电极EABR阈值分别为（145.50±9.85）、（144.75±7.69）、（148.25±11.04）、（146.50±9.20）和（142.25±10.45）CL；行为测听阈值分别为（138.95±7.87）、（138.20±9.04）、（136.50±9.32）、（137.90±10.23）和（134.40±13.43）CL。EABR阈值与行为测听阈值显著相关（r =0.533、0.671、0.580、0.749和0.811，P 均＜0.05）。结论　EABR阈值与行为测听阈值显著相关，EABR为低龄或无法配合行为测听的人工耳蜗植入者术后调机提供一种客观检测手段。     

电诱发听性脑干反应在人工耳蜗植入术后的临床应用分析[论著]

目的　探讨电诱发听性脑干反应（electrically evoked auditory brainstem responses，EABR）的特性和其在判断人工耳蜗植入术后听觉传导通路完整性中的作用，以及不同脉冲宽度的EABR阈值与人工耳蜗植入术后调试行为测试数值之间的相关性，为人工耳蜗植入术后首次开机不会配合行为测试的植入者科学设定刺激参数提供参考。方法　选取郑州市第三人民医院植入诺尔康晨星人工耳蜗（CS-10A植入体）、能配合行为测试的植入者20例，采用行为测试测得阈值（T值）和最大舒适阈（C值），在标准屏蔽室内做ABR检查，采用3、10、20电极分别测脉冲宽度为25、50、75 μs/相的EABR平均阈值，分析引出率和波形分化特点，并对两种数据进行统计学分析。结果　EABR越容易引出波形越清晰，患儿的听觉反应越灵敏，也反映了术后植入体系听觉传导通路越完整（P<0.05）；EABR脉冲宽度为75 μs/相的平均阈值与人工耳蜗的C值有良好的相关性（P<0.05）。结论　EABR检测可客观的判断人工耳蜗植入术后植入体系完整的听觉传导功能，客观评价人工耳蜗植入效果。人工耳蜗调试中，可以通过EABR脉冲宽度为75 μs/相的平均阈值来指导不能配合主观行为测试的植入者C值的判定，为患儿早期开始听觉刺激，建立听觉重塑带来帮助。     

人工耳蜗植入术中电刺激中潜伏期听觉诱发电位的检测

目的 建立人工耳蜗植入术中电刺激中潜伏期听觉诱发电位(electrical evoked middle latency response,EMLR)的检测方法,为进一步评估植入者听觉传导通路及高位听觉反应的特点奠定基础.方法 20例人工耳蜗植入者,其中语前聋14例,语后聋6例,全部使用Cochlear公司Nucleus CI24R (CA)人工耳蜗.术中将言语处理器与计算机接口及听觉诱发电位仪触发端口连接,电极植入后,选取第3号电极,先常规进行电刺激听神经复合动作电位(electrically evoked auditory nerve compound active potentials,ECAP)测试初步了解听神经功能状态,然后进行EMLR检测.选择电刺激听性脑干反应(electrical auditory brainstem response,EABR)模式,采用单极刺激,双相交替脉冲电流方波,脉宽50 ～ 100μs,强度(电流级,current leve1,CL)由ECAP阈值上20 CL起,以5 CL为步长递减或递增,听觉诱发电位仪记录EMLR波形.对ECAP阈值与EMLR阈值进行相关性分析.另外选择6名听力正常健康受试者,行声刺激中潜伏期听觉诱发电位(auditory middle latency response,AMLR)测试,作为EMLR波形和潜伏期的声刺激对照.结果 6例听力正常受试者均可记录到AMLR波形,平均反应阈为(12.5±8.6)dBnHL,接近纯音测听阈值(10.8 ±7.3)dBHL.20例人工耳蜗植入者均可记录到EMLR波形,与AMLR波形相似,但各波潜伏期和波间期缩短,波幅变化不大;语前聋较语后聋总体上波幅小,潜伏期长.EMLR平均阈值为(140.55 ±9.92)CL,低于ECAP的平均阈值 ( 160.75±13.34) CL,差异具有统计学意义(t=10.467,P＜0.01);二者阈值之间呈正相关(r=0.763,P＜0.01).结论 人工耳蜗植入术中可成功记录到EMLR波形,其阈值较ECAP低,可以作为判断植入者中枢高位听觉传导功能的客观检查.     

神经反应遥测技术应用于婴幼儿人工耳蜗植入的作用和体会

目的探讨应用神经反应遥测技术（NRT）在人工耳蜗植入术中监测,术后调机中的作用和经验体会。方法回顾性分析38例经历人工耳蜗植入的婴幼儿的临床资料,收集每例患者在术中、术后开机、调机应用NRT测试电诱发听神经复合动作电位（ECAP）的阈值数据,应用听觉整合量表（IT MAIS）评估行为听觉言语功能。结果38例婴幼儿在术中植电极进入耳蜗后均实施NRT测试,每例测试5个电极,分别为1、6、11、16、22号电极,共测试了190个电极,其中163个电极（85.8%）引出了ECAP,其平均阈值为（163.8±21.2）CL。近端1号电极ECAP阈值显著高于远端22号电极（P<0.05）。从开机到开机后12个月,各电极ECAP阈值无显著变化。3岁以下患儿中,25例患儿在各次NRT测试时所有电极都能引出ECAP,而8例患儿存在1~5个电极不能引出ECAP,在开机12个月后,后者的IT MAIS积分与前者比较差异无统计学意义（P>0.05）。结论人工耳蜗植入后NRT测试的ECAP阈值在近端电极显著高于远端电极,耳蜗内数个电极引不出ECAP不影响术后的听觉言语康复。     

Toward a battery of behavioral and objective measures to achieve optimal cochlear implant stimulation levels in children

OBJECTIVES: Children require audible and comfortable stimulation from their cochlear implants immediately after device activation. To accomplish this, a battery of objective measures may be needed that could include the electrically evoked stapedius reflex (ESR), compound action potential from the auditory nerve (ECAP), and/or auditory brain stem response (EABR). In the present study, the following specific research questions were asked: In children using cochlear implants, 1) Can the ECAP, EABR, and ESR be recorded at the time of cochlear implantation? 2) What is the feasibility of measuring the ECAP, EABR, and the ESR repeatedly without the use of sedation over the first year of implant use? 3) Do ECAP, EABR, and ESR thresholds or behavioral measures change over time? 4) What is the relation between ECAP, EABR, and ESR thresholds and behavioral measures of threshold and comfortably loud levels? DESIGN: In 68 children, ECAP, EABR, and ESR responses as well as behavioral measures of stimulation threshold and maximum stimulation were recorded at regular intervals over the first year of implant use. In each child, responses were recorded to electrical pulses provided by three different electrodes along the implanted array. Visual inspections of the stapedius reflex (V-ESR) evoked by activation of the same three electrodes at the time of surgery were performed in an additional 20 children. RESULTS: ECAP and EABR measures were obtained in more than 84% of electrodes tested and 89% of children tested both in the operating room at the time of implant surgery (OR) and after surgery in nonsedated children. ESRs were recorded by using immittance measures in more than 65% of electrodes tested and 67% of children tested by 3 mo of implant use, but this technique was less successful in the OR and during early stages of device use. V-ESRs and ECAP thresholds were higher in the OR than ESRs and ECAPs at postoperative recording times. EABR and ECAP thresholds did not significantly change over the first 6 and 12 mo of implant use, respectively, whereas ESR thresholds increased. Behavioral measures of threshold decreased over time, whereas maximum stimulation levels rose over time. Behavioral measures of threshold and loudness were highly correlated at all test times. ECAP, EABR, and behavioral measures were lower when evoked by an electrode at the apical end of the implanted array than by more basal electrodes. Behavioral thresholds could be predicted mainly by ECAP thresholds, whereas maximum stimulation levels could best be predicted by ESR thresholds; both were significantly affected by the age at implantation. CONCLUSIONS: A combination of nonbehavioral measures can aid in the determination of useful cochlear implant stimulation levels, particularly in young children and infants with limited auditory experience. These measures can be made in the operating room and can be repeated after surgery when needed. Correction factors to predict threshold stimulation levels should be based on ECAP thresholds or EABR thresholds if necessary. Correction factors should be made for at least one apical and mid-array electrode, should take into account the age of the child, and may have to be revised during the first year of implant use. Maximum stimulation levels may be best determined by using the ESR.     

人工耳蜗植入术中EABR监测的应用

目的探讨人工耳蜗植入术中进行EABR监测的方法，以了解耳蜗电刺激下听觉传导通路的神经反应情况。方法20例人工耳蜗植入患者，男14例，女6例，平均年龄13．6岁，语前聋患者14例，语后聋患者6例。全麻后安置体表记录电极，将PPS与听觉诱发电位仪触发端口连接，并选定听觉诱发电位仪的外触发模式。人工耳蜗电极植入后，先行常规NRT监测，然后将NRT刺激参数改为EABR模式，采用Basic双极刺激，脉宽50μs，强度由200CL起以10CL为步长递减至反应阈值。结果20例患者均记录到EABR，阈上20CL时Ⅲ波．Ⅴ波的平均潜伏期分别为2．04±0．20ms．3．96±0．41ms。相同刺激条件下的EABR反应平均阈值为148．46±11．63CL，NRT反应平均阈值为160．72±13．56CL。一例脑白质轻度发育异常患儿，术中NRT波形引出良好，EABRⅠ～Ⅳ波分化良好，Ⅴ波波形低钝，Ⅴ波／Ⅲ波振幅比〈1／2，考虑可能存在耳蜗核上性神经发育不良，现正在语言康复训练随访中。结论人工耳蜗植入术中进行EABR监测比NRT能提供更完整的．更接近听觉中枢的神经反应信息，能更进一步了解听觉传导通路的功能状态，以期对患者听力康复的效果提供更准确的预测。     

人工耳蜗植入前电刺激听神经复合动作电位检测方法的建立和初步应用

目的 建立术中利用探测电极施行电刺激听神经复合动作电位(electrically evoked auditory nerve compound active potentials,ECAP)检测的方法,在植入人工耳蜗装置前评估患者耳蜗听神经功能状况.方法 选择20例人工耳蜗植入患者,其中耳蜗形态发育正常12例,5例双侧前庭导水管扩大,3例双侧耳蜗Mondini畸形.测试完成后全部使用Cochlear人工耳蜗.全麻后常规人工耳蜗手术进路,行标准耳蜗鼓阶开窗,将自制测试用多通道试验电极置入鼓阶,电极连接Cochlear公司体外言语处理器及自制电刺激发生器,连接电脑,采用Custom Sound EP 2.0软件,调整优化刺激参数进行神经反应遥测(neural responsetelemetry,NRT)初步了解听神经功能状态;刺激强度以5 CL为步长递减或递增至反应阈值给予电刺激脉冲,同时自动记录ECAP波形和阈值.植入人工耳蜗后常规进行NRT检测,记录ECAP波形和阈值;术后1个月患者开机后采集T、C值,将两种电极测试所得阈值和开机C值进行相关性研究,并进行数据统计分析.结果 试验电极ECAP引出率为90%,商业电极ECAP引出率为90%,平均阈值分别为(160.50±15.12)CL和(160.00±11.27)CL,两者经统计学检验没有显著性差异(P>0.05);和开机后C值(177.40±10.61)有明显相关性(R2=0.844,r=0.919).结论 成功建立了术中植入人工耳蜗装置前的ECAP检测方法,为内耳和/或听觉通路发育异常及无残余听力患者提供有效的听神经反应信息,对了解听觉系统发育程度及初步预测术后患者康复情况提供客观依据.     

神经反应遥测技术在人工耳蜗植入术中的监测应用

目的探讨在人工耳蜗植入术中能快速、准确地判断人工耳蜗装置的完好性和患者客观听觉反应的监测方法.方法在40例患儿人工耳蜗植入术中先测定电极阻抗,然后使用神经反应遥测技术(neuralresponsetelemetry,NRT)监测6个电极的电诱发听神经复合动作电位(electricallyevokedauditorynervecompoundactionpotentials,ECAP).结果患儿所有电极阻抗正常,ECAP的检出率分别为97.5%(39例/40例)和92.1%(221个电极/240个电极).其中33例内耳无畸形的患儿所有198个测试电极中有195个电极测出清晰的ECAP波形(98.5%).7例内耳Mondini畸形患者共42个测试电极中有26个电极测得ECAP波形(61.9%),两组之间差异有极显著性.靠近耳蜗底回(高频区)的电极比靠近蜗尖(低频区)的电极具有较高的ECAP反应阈值和较高的ECAP饱和阈值.结论NRT技术可以简便、快速和准确地判断患者的听神经反应,可望成为术中常规监测方法,内耳Mondini畸形是影响ECAP检出的重要因素.     

小儿耳蜗植入后电诱发复合动作电位的阈值及其临床应用

目的：研究应用神经反应遥测（neural response telemetry,NRT)技术，测试电诱发复合动作电位（electrically-evoked compound action potential,ECAP)阈值以指导小儿人工耳蜗映射调图的策略与时机。方法：应用NRT3．0软件对辐值增长函数进行线性拟合，确定ECAP阈值。比较6例儿童植入者在术后1、2、3个月ECAP阈值的变化，同时比较了7例儿童术中、术后ECAP阈值的差异。结果：ECAP幅值增长函数在接近阈值或进入饱和时不再呈线性。术后ECAP阈值保持稳定。各导电极的术中ECAP阈值比术后阈值平均高约15CL，二者有显著性相关（R2＝0．9154）。结论：应选取幅值增长函数的直线段部分进行拟合以确定ECAP阈值。术后应用ECAP阈值指导小儿映射调图时，测试一次ECAP阈值即可。术中ECAP阈值可用作开机时映射图的C值。     

神经反应遥测技术在人工耳蜗植入术中的监测应用

目的：探讨在人工耳蜗植入术中能快速,准确地判断人工蜗装置的完好性和患者客观听觉反应的监测方法。方法：在40例患儿人工耳蜗植入术中先测定电极阻抗,然后使用神经反应遥测技术（neural response telemetry,NRT)监测6个电极的电诱发听神经复合动作电位（electrically evoked auditory nerve compound action potentials,ECAP)。结果：患儿所有电极阻抗正常,ECAP的检出率分别为97．5％（39例／40例）和92．1％（221个电极／240个电极）,其中33例内耳无畸形的患儿所有198个测试电极中有195个电极测出清晰的ECAP波形（98．5％）,7例内耳Mondini畸形患者共42个测试电极中有26个电极测得ECAP波形（61．9％）,两组之间差异有极显著性,靠近耳蜗底回（高频区）的电极比靠近蜗尖（低频区）的电极具有较高的ECAP反应阈值的ECAP饱和阈值。结论：NRT技术可以简便,快速和准确地判断患者的听神经反应,可望成为术中常规监测方法。内耳Mondini畸形是影响ECAP检出的重要因素。     

Characteristics of electrically evoked 'auditory' brainstem responses elicited with the nucleus 22-electrode intracochlear implant

Electrically evoked auditory brainstem responses (EABRs) were measured in cochlear implant patients fitted with the Nucleus 22 electrode system. The typical response waveform consisted of a series of two to three peaks. The largest peak was similar in form to the wave V of acoustically evoked ABRs and was most prominent for stimulus intensities nearly equal to the patients' maximum comfortable (MC) behavioural stimulus level for the test electrode. The first identifiable wave V amplitude was observed at stimulus levels greater than the patients' psychophysical threshold. With increasing stimulus intensity, wave V amplitude increased rapidly to plateau at a level highly correlated with the patients' MC level at the EABR stimulus rate of 17/s. Wave V peak latency was generally shorter than normal ABRs (4.0 cf. 5.5 ms) and varied with electrode position: apical electrodes had shorter latencies than basal electrodes by approximately 0.4 ms. These results suggest that EABRs can be used as an objective estimate of a patient's electrode-specific MC level, once the correlation of EABR growth functions at 17/s to those at clinically employed rates of 250/s has been determined. EABRs may indicate differences in nerve action potential generation for apical and basal electrodes.     

Electrically evoked auditory brain stem responses for lateral and medial placement of the Clarion HiFocus electrode

OBJECTIVE: The purpose of this study was to compare the electrically evoked auditory brain stem response (EABR) for lateral and medial placement of the Clarion HiFocus cochlear implant electrode array via the electrode positioning system (EPS). DESIGN: Twenty-five adult and pediatric cochlear implant recipients participated in the study. Intraoperatively recorded EABRs were evoked by stimuli via three intracochlear electrodes representing apical, medial, and basal locations, and responses were elicited before and after positioner insertion. Evoked potential measures of wave V amplitude and threshold were examined for statistical significance using ANOVA for repeated measures and Chi-Square methods. RESULTS: For a given supra-threshold stimulus level, the increase in EABR wave V amplitude was significantly larger after EPS placement compared to before EPS placement for electrodes 1 (apical) and 13 (basal). Likewise, when the stimulus was decreased to obtain a minimal amplitude, the wave V threshold was significantly lower after EPS placement for electrodes 7 (medial) and 13. The number of measurements that showed decreased wave V threshold after EPS insertion was significantly dependent on intracochlear electrode location. CONCLUSIONS: Placement of the Clarion Electrode Positioning System following HiFocus electrode insertion resulted in a reduction in the electrical current required to activate the auditory system. The effect of the EPS was greatest for the basal location, demonstrated by lower wave V thresholds and a larger percentage increase in wave V amplitude. The EABR reflected electrophysiologic changes relative to lateral-to-medial changes in intracochlear electrode position due to the EPS.