人工耳蜗植入术后神经反应遥测阈值与行为阈值及舒适阈的比较

目的　通过对人工耳蜗植入术后不同患者神经反应遥测 (neuralresponsetelemetry,NRT)阈值与行为反应阈值 (T level,T级 )及舒适阈 (C level,C级 )的比较 ,试图为小年龄或不能给予准确反应的患者客观估算人工耳蜗植入术后行为反应T、C级提供依据。方法　受试对象为使用NucleusCI2 4M型多导人工耳蜗系统的 70例患者。共测试 3 2 9个电极。测试软件为NRT2 0 4版本。NRT阈值的测试采用单极刺激方式 (monopolarstimulationmode) ,分别测试每一位患者的第 3、5、10、15、2 0号电极。T级和C级的测试均于NRT测试同日进行。结果　 70例患者的 3 2 9个电极的NRT波形检出率为 92 7%。同一患者不同编号电极的NRT反应幅值和阈值及不同患者同一编号电极的NRT反应幅值和阈值均存在差异。NRT阈值的均值介于行为反应T级和C级的均值之间。NRT阈值及T、C级的数值自蜗底至蜗顶呈下降趋势。结论　NRT阈值、T级和C级的个体差异较大 ,尚不能根据NRT阈值对T级和C级进行准确的判断。但NRT技术可为不能配合术后调试的儿童患者的行为反应T、C级的估算提供客观的方法。NRT这一新技术仍有待于改进     

儿童人工耳蜗植入术后神经反应遥测阈值与行为反应值的关系

目的：本文通过分析儿童人工耳蜗植入术后神经反应遥测（neural response telemetry,NRT)阈值与行为反应值(T－level,T级）及最大舒适有（C-level,C级）的关系，试图为小年龄，合并其它残疾或不能配合调试的儿童客观估算术后行为反应T、C级提供依据，方法：受试对象为使用Ncleus CI24M型多导人工耳蜗系统的54例儿童患者，测试软件为NRT2．04版本。硬件包括计算机、IF5（Interface5)卡、调试控制界面（processor control interface,PCI)及多导人工耳蜗系统。NRT阈值的测试采用单极刺激方式（monopolar stimulation mode)，分别测试每一例患者的第3、5、10、15、20号电极。T、C级测试均于NRT测试同日进行。结果：54例患者的254个电极的波形检出率为92．1％。所有电极的NRT阈值均大于T级，NRT阈值超过C级的电极占31．5％，NRT阈值的均值介于T级和C级的均值之间。NRT阈值与T级的相关系数为r=0.43(P=0.0000)，而NRT阈值和C级的相关系数为r=0.48(P=0.0000)，这些相关关系为中等强度但地具有显著性。结论：NRT阈值的测试为不能配合术后调试的儿童患者的行为反应T级和C级的估算提供客观的方法。NRT阈值，T级和C级的个体差异较大，尚不能单独根据NRT阈值对T级和C级进行准确的判断。NRT这一技术仍有待于改进。     

儿童人工耳蜗植入术后神经反应遥测阈值与行为反应值的关系

目的 :本文通过分析儿童人工耳蜗植入术后神经反应遥测 (neural response telemetry,NRT)阈值与行为反应阈值 (T- level,T级 )及最大舒适级 (C- level,C级 )的关系 ,试图为小年龄、合并其它残疾或不能配合调试的儿童客观估算术后行为反应 T、C级提供依据。方法 :受试对象为使用 Nucleus CI2 4 M型多导人工耳蜗系统的 5 4例儿童患者。测试软件为 NRT2 .0 4版本。硬件包括计算机、IF5 (Interface 5 )卡、调试控制界面 (processor control interface,PCI)及多导人工耳蜗系统。 NRT阈值的测试采用单极刺激方式 (monopolar stimulation mode) ,分别测试每一例患者的第 3、5、10、15、2 0号电极。 T、C级测试均于 NRT测试同日进行。结果 :5 4例患者的 2 5 4个电极的波形检出率为 92 .1%。所有电极的NRT阈值均大于 T级 ,NRT阈值超过 C级的电极占 31.5 %。NRT阈值的均值介于 T级和 C级的均值之间。NRT阈值与 T级的相关系数为 r=0 .4 3(P =0 .0 0 0 0 ) ,而 NRT阈值和 C级的相关系数为 r=0 .4 8(P =0 .0 0 0 0 ) ,这些相关关系为中等强度但却具有显著性。结论 :NRT阈值的测试为不能配合术后调试的儿童患者的行为反应 T级和 C级的估算提供了客观的方法。 NRT阈值、T级和 C级的个体差异较大 ,尚不能单独根据 NRT阈     

儿童人工耳蜗植入术后神经反应遥测阈值的变化

目的:通过对儿童患者术后神经反应遥测 (NRT) 阈值的分析,总结其变化规律,为儿童人工耳蜗植入术后调试提供帮助.方法:测试40例接受Nucleus CI24R 型多导人工耳蜗单侧植入术的患儿.测试使用澳大利亚Cochlear公司提供的便携式调试系统及NRT3.1版本软件.采用削减算法提取NRT反应波形,分别测试每位患者的第1、5、10、15、20号电极,NRT阈值使用NRT软件计算.分别在开机时、开机3、6和12个月时进行测试.结果:在术后同一测试时间,位于耳蜗不同部位电极的NRT阈值存在差异.耳蜗底部和顶部电极的NRT阈值较低,而位于耳蜗中部的电极NRT阈值较高.经单因素方差分析,不同部位NRT阈值均差异有统计学意义.同一测试电极,随术后开机时间的增长,NRT阈值呈逐渐增加的趋势.经单因素方差分析,术后不同测试时间NRT阈值均差异有统计学意义.结论:术后开机1年内,NRT阈值呈逐渐增加的趋势.若人工耳蜗植入术后调试需要NRT进行辅助,每次均应测试NRT阈值,以便更准确估算患者的行为反应T、C级,尤其对植入术后1年内的儿童患者更为重要.     

人工耳蜗术后编程中神经反应遥测阈值及行为T值的比较分析

目的 了解人工耳蜗术后神经反应遥测(NRT)阈值的变化,NRT与行为T值之间的相关性,以及长期行为T值的变化,为人工耳蜗植入术后的患儿编程提供帮助。 方法 20例接受Nucleus CI24R型多导人工耳蜗植入的患儿,在开机时及6个月调试时对1、11、20号电极进行NRT阈值测试,通过NRT值进行电子耳蜗程序设置;开机后1年和2年对患儿进行行为T值测试,并设置程序;收集开机时及6个月的NRT值分别与1年及2年的行为T值比较。 结果 1号电极开机时和6个月时NRT相互比较差异无统计学意义,11号和22号电极开机时和6个月时NRT差异有统计学意义,三对电极1年与2年行为T值差异都无统计学意义;开机时NRT阈值与行为T值的相关关系中:开机时NRT阈值与行为T值只有22号电极呈正相关,其余两电极中无相关关系。6个月NRT阈值与行为T值的相关关系中:1号电极6个月NRT阈值与行为T值均为正相关;22号电极开机6个月NRT值与1年行为T值为正相关,其他无相关关系。 结论 各电极NRT阈值自开机时基本保持稳定,NRT阈值与行为T值部分电极具有相关性,开机时和最初几次调机时患儿不能配合进行行为测试可以选择NRT阈值来参考调试耳蜗;1年和2年的行为T值也基本稳定,说明患儿术后1年能较好配合行为T值测试,对于配合较好者的患儿可以适当延长调试时间。     

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。     

儿童人工耳蜗植入术后电诱发复合动作电位分析

目的 应用神经反应遥测(NRT)技术,观察人工耳蜗植入后不同时间段的电诱发复合动作电位(ECAP)阈值变化,探讨其对人工耳蜗术后调机的指导意义。方法 对33例使用Nucleus CI24R(CA)型人工耳蜗植入的患儿,于术中及术后1、1.5、2、4、6个月进行ECAP 阈值测试,统计分析其变化规律。结果 33例165个电极的波形检出率为93.3%。电极1、7、11、17、22的术中ECAP阈值与术后30d开机时的ECAP阈值的差异有统计学意义。同一测试电极,随术后开机时间的增长,ECAP阈值呈逐渐增加的趋势。经单因素方差分析,术后不同测试时间ECAP阈值差异有统计学意义。结论 ECAP检出率高,术中可用于检测神经反应;术后可协助估算患者的行为反应T、C级,指导调机,尤其对儿童患者更为重要。     

人工耳蜗植入编程中NRT值和行为测试T值比较分析

目的:了解人工耳蜗植入编程中神经反应遥测(NRT)阈值与行为反应阈值的差别,寻找更好的编程方法。方法:对77例进行澳大利亚24型人工耳蜗植入的患儿在调试时对1、6、11、16、20号电极进行NRT值测试和行为T值测试,在能获得可靠的NRT和行为T值的时候收集数据,并进行统计学分析。结果:各个电极的vNRT值和行为T值的相关系数范围为0.40～0.54。各个电极vNRT的最小值为135μV,最大值为215μV。行为值的最小值为120CL,最大值为190CL。1,6,11,16,20号电极的vNRT和行为T差值的均值为27±14,24±13,31±14,26±13,20±13。vNRT和行为T值的最大差值为65,最小差值为-15。从20号电极到1号电极,平均T值幅度范围为148～159CL,平均vNRT值幅度范围为168～186μV,而且从低频电极到高频电极,vNRT值和行为T值呈上升趋势。结论:用vNRT阈值推测行为T值指导调机编程,个体差异较大,推测结果不是非常可靠,仅用于不能配合行为测试的患者。为了保证编程的准确性,最好对所有进行耳蜗编程的患者用行为T值来编程。     

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。     

人工耳蜗植入经耳蜗造孔注射药物对NRT阈值的影响

目的探讨人工耳蜗植入术中鼓阶内注射药物对NRT阈值的影响。方法收集2015年6月到2016年1月在我院进行Cochlear公司CI512及CI24RE两款弯电极的人工耳蜗植入临床资料,73例双耳极重度感音神经性聋患儿(总共75术耳,其中2例同期双耳手术,平均年龄4岁2个月)分为3组,地塞米松组:耳蜗造孔后于鼓阶内注入地塞米松1ml;透明质酸组:耳蜗造孔后于鼓阶内注入透明质酸1ml;未注药物组:耳蜗造孔后鼓阶内未注射任何药物。收集术中NRT监测数据及术后2周开机NRT阈值数据,5个电极(第1,6,11,16,22电极)的阈值进行分析。以单因素方差分析(ANOVA)分析三组NRT反应电极数及阈值变化;t检验及Wilcoxon符号等级检定来检验各组术中及开机时反应电极阈值变化;以卡方检定分别检验三组间低、高频电极无反应的电极个数比率差异。结果三组间在术中可监测出NRT电极个数(P=0.64)及术后开机NRT有反应的电极个数(P=0.85)差异无统计学意义。术中监测的N、DXM、HA等三组NRT平均阈值(P=0.13)及术后开机NRT平均阈值(P=0.77)的差异无统计学意义。但在高频段电极的术中监测时,DXM组的反应阈值显著低于HA组。各组在术后开机测得的NRT阈值比较术中监测的阈值明显下降,差异有统计学意义(P<0.01)。所有低频电极的反应阈值均较高频电极的阈值为低,差异有统计学意义(P<0.01)。结论人工耳蜗植入术中于鼓阶注入地塞米松或透明质酸并不影响NRT检测时有反应的电极数量;但在高频电极中,鼓阶注入地塞米松可于术中降低NRT反应阈值。     

Relation between neural response telemetry thresholds, T- and C-levels, and loudness judgments in 12 adult nucleus 24 cochlear implant recipients

OBJECTIVE: The primary purpose of this study was to determine if the contour of visual (vNRT) or predicted (tNRT) neural response telemetry (NRT) thresholds across electrodes could predict the contour of behaviorally programmed T-levels (minimum stimulation) and/or C-levels (maximum stimulation) across electrodes for well-fit MAPs. The secondary purpose was to determine the relation between NRT thresholds and loudness judgments obtained at the subject's MAP rate (250, 900, 1200, or 1800 pulses per second [pps]) and the NRT stimulus rate (80 pps). DESIGN: Twelve adult Nucleus 24 cochlear implant recipients participated in the study. The T- and C-levels from a preferred MAP, which had been worn for a minimum of 3 mo, were used in this study. Electrically evoked compound action potentials were measured on 11 active electrodes with NRT software (v3.0). Ascending loudness judgments from first hearing to maximum acceptable loudness were completed on these electrodes with the subject's preferred MAP rate stimulus, using the R126 (v.2.0) software and with an 80 pps rate stimulus, using the NRT software (v3.0). All measures were repeated approximately 1 mo later to determine their reliability. RESULTS: The reliability of the behavioral and objective measures was very high from the first to the second half of the study. The mean tNRT thresholds had a lower reliability (r = 0.73) than vNRT thresholds (r = 0.91). The loudness judgment dynamic range was notably different between rates. The NRT rate (80 pps) stimulus resulted in the narrowest dynamic range followed by increasingly wider dynamic range as the MAP rate increased. The NRT thresholds had a stronger correlation with loudness judgments made with the NRT rate stimulus than with the MAP rate stimulus. The group mean NRT thresholds were significantly correlated with C-levels (vNRT r = 0.69) (tNRT r = 0.66) but not T-levels. The relation between NRT thresholds and T- and C-levels varied for different MAP rates, with the NRT thresholds being closest to the C-levels for the 250 pps MAP rate. Each subject's vNRT thresholds and MAP levels were examined by fitting a third-order polynomial to the data. This analysis revealed significant variability demonstrating that no one fit predicts T- and C-levels well for all subjects. CONCLUSIONS: The results of this study provide important insight into the relation between NRT thresholds and loudness judgments for different stimulation rates and T- and C-levels at various MAP rates. The loudness judgment dynamic range and MAP dynamic range (T- and C-levels) varied notably for different stimulation rates. As a result, the relation of NRT thresholds to these measures also varied with stimulation rate. Overall, the mean vNRT thresholds fell higher in the loudness judgment dynamic range than the tNRT thresholds. Mean NRT thresholds fell between the judgments of medium soft and maximum acceptable loudness for all stimulation rates. Mean vNRT thresholds fell above C-levels, whereas almost half of tNRT thresholds fell just below C-levels. However, the relation between NRT thresholds and C-levels varied substantially for different MAP stimulation levels. In addition, there is substantial individual variability in the relation between NRT thresholds and MAP levels that is not reflected in the group data. The prediction of the contour of T- and C-levels from the contour of NRT thresholds across electrodes would not be appropriate for half of the subjects. Therefore, great care should be taken when applying a fitting rule that incorporates NRT thresholds without considering these individual differences. For adults who can provide appropriate loudness judgments and threshold responses it appears to be most efficient to primarily use behavioral measures to create MAPs.     

客观听觉监测技术在人工耳蜗植入中的临床应用

目的：比较电诱发镫骨肌反射技术（ESR）及神经反应遥测技术（NRT）的临床特点及应用价值。方法：对21例行Cochlear Nucleus 24R（CA）型人工耳蜗植入者分别选取1、7、11、17、22号电极,应用Cochlear公司提供的NRT3.0软件分别进行术中ESR和NRT检测、术后主观心理物理测试,测定电诱发镫骨肌反射阈值（ESRT）、电诱发听神经复合动作电位阈值（ECAP）和听阈阈值（T-levels）,并对其ESRT、ECAP和T-levels进行相关性研究。结果：ESRT、NRT、T-levels检出率分别为96.19%、93.33%、100%。ESRT平均阈值为206.61±10.74、208.48±13.64、205.52±14.63、203.76±12.97、199.5±11.19;NRT平均阈值分别为184.11±6.35、188.55±11.70、187.00±12.29、181.85±13.22、179.00±10.50;T-levels平均阈值分别为145.48±18.66、148.62±8.22、146.62±18.08、142.52±13.11、140.33±13.68。各电极ESRT阈值均远远大于心理物理测试得到的T-levels阈值。ESRT、NRT、T-levels三者的均值趋势有较强的一致性。术中测试时间、测试方式、单方检出率、ESR均优于NRT。以所有电极作为观察对象,ESRT与NRT的相关性为0.69,NRT与T值的相关性为0.62,ESRT与T值之间的相关性为0.39。结论：术中应用ESR和NRT技术,可以第一时间反映植入体及听觉传导通路的情况,相对于NRT而言,ESR更为灵活、方便、精确和直观,在低龄患儿术后调试方面前者显示出更加客观的优越性。     

Comparison of EAP thresholds with MAP levels in the nucleus 24 cochlear implant: data from children

OBJECTIVE: The purpose of this study is to examine the relationship between the electrically evoked compound action potential (EAP) thresholds and the MAP thresholds (T-levels) and maximum comfort levels (C-levels) in children implanted with the Nucleus 24 device. DESIGN: EAP thresholds were measured using the Neural Response Telemetry system of the Nucleus 24 device. Twenty children implanted with the Nucleus 24 cochlear implant participated in this study. EAP thresholds were compared with the behavioral measures of T- and C-level used to construct the MAP these children used on a daily basis. For these subjects, both EAP and MAP T- and C-levels were obtained the same visit, which occurred at 3 to 5 mo postconnection. RESULTS: EAP thresholds were shown to fall between MAP T- and C-level for 18 of 20 subjects tested; however, considerable variability across subjects was noted. On average, EAP thresholds fell at 53% of the MAP dynamic range. Correlations between EAP threshold and MAP T- and C-level improved substantially when combined with behavioral measures obtained from one electrode in the array. CONCLUSIONS: Moderate correlations were found between EAP thresholds and MAP T- and C-levels for the children participating in this study. However, a technique is described for improving the accuracy of predictions of MAP T- and C-levels based on EAP data combined with a small amount of behavioral information.     

The relationship between EAP and EABR thresholds and levels used to program the nucleus 24 speech processor: data from adults

OBJECTIVE: The objective of this study was to determine the relationship between electrically evoked whole nerve action potential (EAP) and electrical auditory brain stem response (EABR) thresholds and MAP threshold (T-level) and maximum comfort level (C-level) for subjects who use the Nucleus 24 cochlear implant system. DESIGN: Forty-four adult Nucleus 24 cochlear implant users participated in this study. EAP thresholds were recorded using the Neural Response Telemetry System developed by Cochlear Corporation. EABR thresholds were measured for a subset of 14 subjects using standard evoked potential techniques. These physiologic thresholds were collected on a set of five electrodes spaced across the cochlea, and were then compared with behavioral measures of T-level and C-level used to program the speech processor. RESULTS: EAP thresholds were correlated with MAP T- and C-levels; however, the correlation was not strong. A technique for improving the correlation by combining measures of T- and C-levels made on one electrode with the EAP thresholds was presented. Correlations between predicted and measured T- and C-levels using this technique were 0.83 and 0.77, respectively. Similar results were obtained using the EABR thresholds for a smaller set of subjects. In general, EABR thresholds were recorded at levels that were approximately 4.7 programming units lower than EAP thresholds. CONCLUSIONS: Either EAP or EABR thresholds can be used in combination with a limited amount of behavioral information to predict MAP T- and C-levels with reasonable accuracy.     

Evaluation of streamlined programming procedures for the Nucleus cochlear implant with the Contour electrode array

OBJECTIVE: The objective of this study was to evaluate streamlined programming procedures for the Nucleus cochlear implant system with the Contour electrode array. DESIGN: Phase 1 involved an examination of the clinical MAPs for the first 103 recipients implanted with the Contour electrode array in the Melbourne Cochlear Implant Clinic, to examine the ability to predict the entire MAP based on a smaller number of clinically determined T- and/or C-levels. In phase 2, a subset of the streamlined procedures was selected and clinically evaluated, using speech perception and subjective preference measures. In the first study, the clinical MAP was compared with a MAP based on interpolating across three behavioral T-levels and three behavioral C-levels in a group of newly implanted subjects. The second study investigated the use of a single interpolated profile as the basis to creating the entire MAP. Initial evaluation compared the clinical MAP with two streamlined MAPs, one in which the C-level profile was derived from interpolation across a subset of T-levels and one in which the T-level profile was derived from interpolation across a subset of C-levels. In this case, the interpolated profile was based on five behavioral measures. Subsequently, the use of either three or a single T-level measure as the basis for the interpolated T-level profile was evaluated. Eighteen subjects, who were experienced with the clinical MAP before enrollment in the study, participated in the initial evaluation. The subjects were selected to include a group whose RMS deviation from clinical MAP levels, as determined in Phase 1, was greater than that of the wider population. RESULTS: The Phase 1 analysis showed that as expected, larger differences were observed between the clinical and derived MAP levels as interpolation was applied across fewer measured electrodes and that the use of a single interpolated profile to create the entire MAP resulted in the greatest deviation. No significant group mean difference was found in speech perception scores for newly implanted subjects when mapped with the clinical versus the streamlined MAP based on three behavioral T- and three behavioral C-level measures. For some individual subjects, scores were higher with the streamlined MAP. Subjective reports from the comparative performance questionnaire were consistent with these findings. No significant group mean difference in speech perception scores was found in comparing the clinical MAP with the streamlined MAPs based on a single interpolated T- or C-level profile created from five behavioral measures. Individual effects were observed; however, there was no consistent finding across subjects. The use of three rather than five behavioral T-level measures in the procedure did not result in significantly lower group mean scores; however, significantly poorer scores were obtained for three of the 10 individual subjects. The use of a MAP based on a single behavioral measure did result in poorer speech perception scores when compared with the MAP based on five behavioral T-level measures. These findings were consistent with subjective results from the performance questionnaires administered to determine preference for program across a range of listening situations. CONCLUSIONS: Two streamlined programming procedures are recommended for use in the clinical setting: (1) interpolating across three measured T-levels and three measured C-levels and (2) interpolating across five measured T- or C-levels and using the interpolated profile for fitting of the alternative profile.     

神经反应遥测技术在人工耳蜗术后调试中的应用

目的通过对小儿人工耳蜗植入者术后言语处理器调试中运用NRT（神经反应遥侧）技术效果的分析．探讨NRT在人工耳蜗术后调试中的应用价值。方法选取10例术后主观调试配合欠佳的儿童．用Cochlear公司NRT3．0编程软件进行ECAP波形检测并测定ECAP阈值，利用测试结果判断主观阈值（T-值）和最大舒适阈（C-值），并得出言语处理器映射图（Map）。术后6个月行声场听阈测听。结果86．2％的电极引出ECAP波形，开机调试时反应阈值较小，以后逐渐升高，3～4个月左右闽值逐渐趋于稳定，而且靠近蜗底的阈值比蜗尖高。声场平均听阈为30～40dBSPL。经过言语康复训练，获得良好的效果。结论NRT技术可为术后快速准确地调试言语处理器提供客观依据．     

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.     

Cochlear implantees: Analysis of behavioral and objective measures for a clinical population of various age groups

Abstract

Introduction

As of 2014 more than 1200 patients have received a cochlear implant (CI) at Oslo University Hospital (OUS) and approximately half of them have been children. The data obtained from these patients have been used to develop a comprehensive database for a systematic analysis of several objective measurements and programming measurements. During the past 10 years, we have used an objective measurements protocol for our CI surgeries. Our intra-operative protocol includes: Evoked Compound Action Potentials (ECAP), visually observed Electrically evoked Stapedius Reflex Threshold (ESRT), and electrode impedances. Post-operative (Post-OP) programming sessions typically begin 4–6 weeks after surgery and continue on a scheduled basis. The initial programming data include threshold levels (T-levels) and comfortable levels (C-levels) for the different patient age groups. In this study, we compared initial stimulation levels and stimulation levels after at least 1 year of CI with objective measurements obtained intra-operatively.

Method

This study focused on the development of a comprehensive database of detailed intra-operative objective measures and post-OP programming measurements from a group of 296 CI patients who received the same type of CI and electrode configuration (Cochlear^® Corporation CI with Contour^® electrode). This group included 92 bilateral CI patients. Measurements from 388 CI devices were studied. Patients were divided into 5 different age groups at the age of implantation: 0–2, 2–5, 5–10, 10–20, and above 20 years in order to investigate age-related differences in programming levels and objective measurements. For the comparison analysis we used T- and C-levels obtained after the last day of initial programming and also after at least 1 year implant use. These programming levels were then correlated with some of the intra-operative objective measurements.

Results

T-levels were found to be the lowest for the youngest patient group and increased with age. C-levels varied within age groups and frequency range. Patients above 20 years of age had the highest comfort levels in the low to mid-frequencies (electrodes 22–8) and the lowest comfort levels in the high-frequency range (electrodes 1–7). Correlation coefficients between intra-operative objective measurements and programming levels were found to be in the range of no correlation to moderate correlation. Adult patients had the most significant correlation coefficients between ECAP thresholds and T-levels in the low frequencies. The younger patients aged 10–20 years and 5–10 years had more significant correlations in the higher frequency channels compared to the other age groups. Intra-operative visually observed ESRTs and electrode impedances were not significantly correlated with initial or stable programming levels for the children or adults.

Conclusion

Analyzing initial and follow-up mapping levels from previous patients is very important for a CI Center in terms of quality control. The mean T/C-levels reported in this study can provide guidance to our programming audiologists and help them determine the initial programming levels to be stored in the speech processor, especially for very young patients. Unfortunately intra-operative objective measures in our study, such as ECAP, ESRT, and electrode impedances did not provide statistically significant correlations that may help to predict the programming T- and C-levels for all patients. However, we have observed cases where the intra-operative objective measures of ESRT and TECAP profiles were very similar to an individual's MAP profile. It was not possible, however, to determine why some patients did not have an objective measures profile that was similar to their programming levels profile.