Analysis of audiological results of patients referred from newborn hearing screening program

Conclusion: As tools of confirmation of sensorineural hearing loss in neonates who are ‘referred’ from a newborn hearing screening program, both ASSR and DPOAE have high sensitivity and specificity. In addition, ASSR can be used as a substitute for ABR. Objectives: To analyze the confirmative audiological results of patients referred from a newborn hearing screening program. Patients and method: From January 2007 to December 2013, hearing tests were performed on 474 babies (804 ears) who were ‘referred’ from the hospital or other maternity centers. Auditory brainstem response (ABR), auditory steady-state response (ASSR), and distortion product otoacoustic emissions (DPOAE) were used for hearing evaluation. Results: Of 474 babies (804 ears), 232 had normal hearing, while 242 babies (358 ears) had over 30 dB nHL threshold from ABR. Among the 156 babies (312 ears) who underwent both ABR and ASSR, the mean ASSR threshold had a strong correlation with ABR threshold (r = 0.942, p < 0.001). Assuming that ABR results were the yardstick of abnormal hearing, sensitivity and specificity of ASSR to ABR were 90.6% and 95%. DPOAE tests were performed on 180 babies (360 ears), with sensitivity of 85.9% and specificity of 84.4%.     

听性稳态诱发反应在听力异常婴儿的诊断意义

目的听性稳态诱发反应（auditory steady—statere sponse，ASSR）新技术与视觉强化测听（vision reinforcement audiometry，VRA）阈值的相关性分析研究，探讨听神经病症侯群及其鉴别诊断。方法10例（20耳）对照组，年龄6～12个月，测得ASSR和VRA的正常阈值。16例（26耳）异常听力组患儿（年龄在3～6个月），根据其所患疾病分为3个亚组：Ⅰ组为早孕感染组5例（8耳），Ⅱ组为窒息缺氧组5例（10耳），Ⅲ组为高胆红素血症组6例（8耳），检测畸变产物耳声发射（DPOAE）、听性脑干反应（ABR）潜伏期、肌反射值与ASSR和VRA及其相关性结果对照。结果Ⅰ组中2例次（2耳次）为单纯疱疹病毒感染。5例次（8耳次）DPOAE消失，4例次（6耳次）ABR波Ⅰ潜伏期延长、Ⅰ—Ⅴ波间潜伏期缩短，3例次（6耳次）500Hz和1000Hz的镫骨肌反射正常，2例次（2耳次）镫骨肌反射阈偏高，初步推测单纯耳蜗性病变，排除听神经病可能，测得ASSR平均估计阈值与VRA平均阈值具有很好的相关性（r=0．95～0．98）。Ⅱ组中4例次（8耳次）畸变产物耳声发射消失，其中1例次（2耳次）ABR波Ⅰ、波Ⅲ、波Ⅴ消失和肌反射消失，3例次（5耳次）ABR波Ⅰ消失和波Ⅲ及波Ⅴ潜伏期延长，以及肌反射消失。2例次（3耳次）Ⅰ-Ⅲ波间潜伏期延长，肌反射也消失。推测可能为听神经病症侯群（耳蜗至脑干下听觉传导通路受损）伴有耳蜗功能障碍，测得ASSR平均估计阈值与VRA平均阈值具有较好的相关性（r=0．72～0．84）。Ⅲ组中6例次（8耳次）DPOAE存在，4例次（5耳次）ABR波Ⅰ、Ⅲ、Ⅴ和肌反射消失，2例次（3耳次）Ⅰ—Ⅴ波间潜伏期延长，镫骨肌反射阈正常偏高，初步分析推测为听神经病症侯群病损在脑干以上，测得ASSR平均估计阈值与VRA平均阈值具有很弱的相关性（r=0．43～0．64），ASSR阈值和VRA阈值不一致，进一步说明这组的病损应该在脑干或皮层。3个亚组的每个频率（0．25、0．5、1、2,4kHz）平均ASSR和VRA阈值差值比较，差异都具有统计学意义（F检验，P〈0．05、P〈0．01、P〈0．01、P〈0．05、P〈0．05）。结论通过ASSR阈值和VRA阈值相关性技术研究或许可提供诊断及鉴别诊断在各种频率听力障碍婴儿的听神经病症侯群（病变高位）、听神经病症侯群伴有耳蜗功能障碍（病变低位）以及单纯耳蜗性病（非听神经病）。     

小儿蜗后听觉神经损害的听力学特征

目的 探讨包含了听神经病在内的以听性脑干反应(ABR)严重异常、畸变产物耳声发射(DPOAE)正常为特征的蜗后听觉神经功能障碍小儿的听力学特征.方法 选取2002～2008年在广州市妇女儿童医疗中心听力专科检查中ABR严重异常(波Ⅴ阈值≥80 dB nHL)、DPOAE正常、排除中耳传导功能异常的患儿182例(350耳)为研究对象,患儿年龄4天～13岁,平均年龄15.67个月.结果 ①182例蜗后听觉神经损害患儿中,107例(58.79%)新生儿期有高胆红素血症,其中34例(18.68%)伴发核黄疸.在首次就诊的原因中,以"运动障碍"为主诉者最多,占32.42%(59例).因新生儿期听力损害高危因素进行听力评估而发现者占26.37%(48例).在伴随的疾病中,64例(35.16%)确诊伴随有脑性瘫痪.②本组182例蜗后病变患儿中,168例(占92.31%)双耳患病,14例(占7.69%)单耳患病.168例双耳均为蜗后病变的患儿中,最大强度刺激双耳均无Ⅰ波分化病例所占比例最高(94例,占55.95%).③在患蜗后听觉神经功能障碍的350耳中,172耳最大强度声刺激(103 dB nHL)ABR无波分化,69耳仅见波I分化,40耳见波I+Ⅲ+V分化,25耳仅见波V分化,20耳见波I+Ⅲ分化,15耳见波Ⅲ+V分化,5耳见波I+V分化,4耳见波Ⅲ分化.结论 高胆红素血症是包含听神经病在内的小儿蜗后听觉神经损害的最主要致病因素.小儿蜗后病变以双耳对称发病多见,双耳不对称患病的现象亦可出现,但相对少见.在蜗后听觉神经功能损害类型中,最常见的类型为ABR从波 I 开始就严重异常.小儿蜗后病变的听力学特征呈多样化.     

听性稳态反应与听性脑干反应阈值的比较

目的:通过比较同一组聋儿听性脑干反应(ABR)和听性稳态反应(ASSR)的反应阈值,对ASSR的临床应用价值作出评价。方法:分别记录65例年龄在2.5个月~5.5岁聋儿的ABR及ASSR结果并进行比较及相关分析。结果:本组聋儿ABR反应阈值左右耳分别为(85.82±12.39)和(82.70±14.93)dB nHL;ASSR 4个测试频率的反应阈值左耳为(86.91±16.70)(、90.32±16.11)、(91.02±16.58)、(89.80±17.08)dB HL,右耳为(85.15±18.16)(、89.32±17.76)(、90.41±18.87)(、85.15±17.03)dB HL。ASSR 4个测试频率的反应阈值与ABR结果的相关系数分别为左耳0.622、0.721、0.757、0.714和右耳0.613、0.732、0.795、0.739。结论:ASSR与ABR测试结果有显著的相关性,而ASSR所获得的是分频资料,因此这种测试方法有较高的临床应用价值。     

同步多频听觉稳态诱发反应与听性脑干诱发电位相关性研究

目的探讨同步多频听觉稳态诱发反应(auditory steady-state responses to multiple simultaneous stimuli,MSS-ASSR)与听性脑干诱发电位(auditory brainstem response audiometry,ABR)的关系。方法受试者为不同程度听力损失的儿童70名(140耳),年龄范围为3月龄～6岁。测试状态为水合氯醛镇静睡眠。仪器采用美国INTELLEGENT HEARING的诱发电位仪,MSS-ASSR及ABR测试的软件分别为SMART ASSR和SMART EP,刺激声信号的载波频率为0．5kHz、1kHz、2kHz及4kHz。左耳上述各个载波频率的调制频率分别为77Hz、85Hz、93Hz、101Hz,右耳为79Hz、87Hz、95Hz、103Hz。测试时,双耳八个调幅调制声信号经ER-3A标准插入式耳机同时给出。ABR的刺激声为短声,极性为交替波,刺激速率为19．3次／分,耳机也是ER-3A插入式耳机。受试儿先进行ABR测试、然后进行MSS-ASSR的测试,分别以降10升5法得出二者的反应阈。将MSS-ASSR 0．5kHz、1kHz、2kHz和4kHz的反应阈与ABR反应阈比较,以SPSS 10．0软件进行相关性分析。结果除去58耳ABR无反应外,剩余82耳ABR反应阈与MSS-ASSR 0．5kHz、1kHz、2kHz、4kHz的反应阈相关性具有显著性意义(P=0．000)。Pearson相关系数分别为0．757,0．854,0．906,0．912。结论MSS-ASSR作为儿童听力定量诊断的客观方法有很大的临床应用价值。     

Comparison of auditory steady-state response and click-evoked auditory brain response in infants with different types and degrees of hearing loss

Abstract

Background: Auditory steady-state response (ASSR) and click-evoked auditory brain response (c-ABR) have been used for hearing assessment for decades years, the correlation of the two methods and the effects of type and degree of hearing loss (HL) to the correlation in infants younger than 6?months of age are unclear.

Objectives: To compare the correlation of ASSR and c-ABR and then to analyse the effects of type and degree of HL on the correlation in infants younger than 6?months of age.

Material and methods: Retrospective study comparing ASSR thresholds at various frequencies with c-ABR thresholds. 182 ears from 96 infants were assessed and classified according to types and degrees of HL.

Results: The correlation coefficients were: 0.823, 0.864, 0.891, 0.871, 0.908, 0.915 and 0.913 between ASSR thresholds at 0.5, 1, 2, 4, 2–4, 1–2–4, 0.5–1–2–4?kHz and c-ABR thresholds respectively. The correlation coefficients in the group of sensorineural HL (SHL) (r?=?0.763–0.900) were higher than conductive HL (r?=?0.309–0.619) across all frequencies. The coefficients of severe-profound SHL (r?=?0.595–0.790) were higher than mild-moderate SHL (r?=?0.434–0.687) across all frequencies.

Conclusions and significance: ASSR was one valuable cross-check measure by providing frequency specific information in auditory assessment.     

气导和骨导ABR在先天性外耳道闭锁小儿听力评估中的应用

目的研究先天性外耳道闭锁小儿气导和骨导短声诱发的听性脑干反应（auditory brain stem response,ABR）的特点,评价骨导ABR的应用价值。方法将受试者分为两组。组1（闭锁组）为16例（21耳）先天性外耳道闭锁患者,年龄在1～13岁之间,平均为5．62岁;组2（对照组）为正常听力小儿15例（25耳）。年龄在1～13岁之间,平均为6．1岁。比较两组气、骨导ABR的特点。结果闭锁组气、骨导ABR反应阈值分别为（73．81&#177;7．4）dBnHL和（6．19&#177;4．98）dBnHL,正常组分别为（23．20&#177;4．76）dBnHL和（5．60&#177;5．07）dBnHL。30dBnHL刺激强度下闭锁组骨导ABR潜伏期与对照组相比差异无显著性。闭锁组气、骨导ABR阈值差值与正常组相比差异有显著性。结论骨导ABR可以用于评估先天性外耳道闭锁患者的耳蜗功能。     

Auditory sensitivity in children using the auditory steady-state response

OBJECTIVE: To determine the effectiveness of auditory steady-state response (ASSR) as a measure of hearing sensitivity in young children suspect for significant hearing loss. DESIGN: Within-subject comparisons of click auditory brainstem response (ABR) thresholds and ASSR thresholds. SUBJECTS: The study population comprised 42 children suspect for hearing loss and subsequently referred for hearing assessment using electrophysiologic techniques. MAIN OUTCOME MEASURES: Electrophysiologic threshold responses for click ABR and ASSR stimuli (0.5, 1, 2, and 4 kHz) for right and left ears. RESULTS: Based on ABR and ASSR thresholds, 50% of the subjects demonstrated significant hearing loss in the severe to profound range. In some subjects, ASSRs were present at higher stimulus levels when click ABRs were absent. Significant correlations (P<.05) were found between high-frequency ASSR and click ABR thresholds for this study sample. For some subjects, ASSR findings suggested differences between ears that were not observable from the no-response click ABR results. CONCLUSIONS: Auditory steady-state response testing may provide additional information for children who demonstrate hearing levels in the severe to profound range. This information may be helpful when selecting the ear for cochlear implantation for a young hearing-impaired child. Multiple objective methods, such as ABR and ASSR testing, may be needed to determine accurate hearing sensitivity for young children being considered for sensory devices, and in particular, cochlear implants.     

Is auditory brainstem response a prognostic factor in patients with sudden sensorineural hearing loss?

Abstract

Background: Serum thyroid hormone levels are closely related to the normal functioning of the cochlea. However, the relationship between initial auditory brainstem response (ABR) results and levels of thyroid hormone remained unclear until we adopted ABR as a prognostic factor in Idiopathic sudden sensorineural hearing loss (ISSNHL) patients.

Objective: This investigation aimed to elucidate the association between ABR and outcomes in patients with ISSNHL.

Material and methods: Thirty-three patients presenting with unilateral ISSNHL underwent blood sampling and ABR tests on the day of admission. The mean latencies of the ABR results were compared among the groups which were classified by ISSNHL outcome, based on Siegel’s criteria. The association between the ABR results and the thyroid hormone serum levels (TSH, T3, and free T4) were assessed.

Results: The overall successful recovery rate was 60.6% (n?=?20). The mean latencies of all the ABR parameters were not significantly different between the different treatment outcome groups (Mann–Whitney U test). Wave V latency, III–V interval and I–V interval were negatively associated with T3 serum levels.

Conclusion: The results indicate that clinical caution should be exercised when conducting ABR tests without assessing thyroid hormone levels.     

轻度感音神经性听力损失婴儿骨导ABR检测结果分析

目的探讨骨导听性脑干反应(ABR)检测在婴儿轻度感音神经性听力损失诊断中的价值。方法分别对30例(52耳)轻度感音神经性听力损失婴儿(患儿组)和30例(60耳)听力正常婴儿(正常组)行骨、气导ABR检测,并对两组结果进行分析比较。结果从40 dB nHL刺激强度开始,随着刺激强度下降,患儿组骨导ABR波V引出率逐渐下降;在40 dB nHL刺激强度下,患儿组骨导ABR波Ⅰ、Ⅲ、Ⅴ潜伏期较正常组稍延长,但差异无显著统计学意义(P>0.05)。患儿组骨、气导ABR反应阈均较正常组显著升高(P<0.05),但两组骨气导反应阈差值无明显差异(P>0.05)。结论骨导ABR检测对轻度感音神经性听力损失婴幼儿听力损失性质的鉴别诊断和评估具有重要的临床参考价值。     

短纯音诱发的听性脑干反应测试中声诱发短潜伏期负反应研究

目的 总结在有听力损失儿童中行短纯音诱发的听性脑干反应(tbABR)测试时记录到的声诱发短潜伏期负反应(acoustically short latency negative response,ASNR)的特点.方法 在有听力损失的0～6岁儿童中应用SmartEP听觉诱发电位仪记录短声和短纯音ABR的反应阈,在记录到ASNR的受试者中分析其反应阈和潜伏期.结果 在所有80受试耳中共7耳(8.75%)在cABR测试中引出ASNR,40耳(50%)在tbABR测试中引出ASNR,其中1 kHz引出率最高(37耳,46.25%),2 kHz次之(25耳,31.25%).引出ASNR者ABR波V反应阈最低65 dB nHL,ASNR反应阈最低80 dB nHL.0.5、1、2和4 kHz短纯音诱发的ASNR潜伏期分别为6～8、5～7、3～5、3～4 ms.随刺激强度的增加,其潜伏期缩短.结论 有听力损失的儿童tbABR测试中可以记录到AS-NR,但不影响以波V反应阈评估听力.     

Obstructive Sleep Apnea–Hypopnea Ssyndrome and Hearing in Children

ObjectiveTo explore the relationship between hypoxemia and hearing in children with obstructive sleep apnea–hypopnea syndrome. Methods Auditory brainstem responses (ABRs) were recorded in 68 ears and distortion product otoacoustic emissions (DPOAEs) in 60 ears in children with OSAHS and type “A” tympanograms, and in 30 ears in normal children.ResultsABR latencies of waves I, III and V, and I–III, III–V and I–V intervals were not statistically different between OSAHS and normal children. Wave I latency was delayed in children with OSAHS compared to normal children3 (P < 0.05). DPOAE amplitudes in children with mild OSAHS were lower than normal children at 8 kHz (P < 0.05). DPOAEs were lower at 6 kHz and 8 kHz in children with moderate/severe OSAHS than normal children (P < 0.05).ConclusionCochlear function was affected when AHI was at or greater than 10/hour. ABR and DPOAE can be used to detect early changes in auditory function in children with OSAHS.     

Threshold changes of ABR results in toddlers and children

IntroductionAuditory brainstem response (ABR) is a clinically established method to identify the hearing threshold in young children and is regularly performed after hearing screening has failed. Some studies have shown that, after the first diagnosis of hearing impairment in ABR, further development takes place in a spectrum between progression of hearing loss and, surprisingly, hearing improvement.ObjectiveThe aim of this study is to evaluate changes over time of auditory thresholds measured by ABR among young children.Material and MethodsFor this retrospective study, 459 auditory brainstem measurements were performed and analyzed between 2010 and 2014. Hearing loss was detected and assessed according to national guidelines. 104 right ears and 101 left ears of 116 children aged between 0 and 3 years with multiple ABR measurements were included. The auditory threshold was identified using click and/or NB-chirp-stimuli in natural sleep or in general anesthesia. The frequency of differences of at least more than 10 dB between the measurements was identified.ResultsIn 37 (35%) measurements of right ears and 38 (38%) of left ears there was an improvement of the auditory threshold of more than 10 dB; in 27 of those measurements more than 20 dB improvement was found. Deterioration was seen in 12% of the right ears and 10% of the left ears. Only half of the children had stable hearing thresholds in repeated measurements. The time between the measurements was on average 5 months (0 to 31 months).ConclusionHearing threshold changes are often seen in repeated ABR measurements. Therefore multiple measurements are necessary when ABR yields abnormal. Hearing threshold changes should be taken into account for hearing aid provision.     

Evoked otoacoustic emissions and auditory brainstem responses: concordance in hearing screening among high-risk children

Objective Evoked otoacoustic emissions (OAEs) and diagnostic auditory brainstem responses (ABRs) were determined in 379 high-risk children referred for hearing screening.

Material and Methods This was a retrospective, cross-sectional study. The records of 379 children referred for hearing screening between January 2002 and March 2003 at the Ear Unit of the Philippine General Hospital were evaluated.

Results Of the 379 children, 53.6% were male and 46.4% were female and the mean age was 41±47 months. The age distribution was as follows: ≤12 months, 32.2%; 12–24 months, 52.2%; and>24 months, 11%. Out of 229 right and 232 left ears, 111 (48.5%) and 112 (48.3%) had “pass” responses and 113 (49.3%) and 116 (50.5%) had “refer” responses, respectively. Five right and four left ears had “noise” responses. Out of 266 right and 209 left ears, the ABR results showed 72 (27.1%) and 30 (14.4%) with normal auditory pathways and 194 (72.9%) and 179 (85.6%) with abnormal auditory pathways, respectively. Of the 131 children whose parents gave their consent for concomitant OAE and ABR testing, agreements were observed between the two tests in terms of classifying the results as normal or abnormal of 78.9% (κ=0.51; p=0.00) in right and 78.6% (κ=0.51; p=0.00) in left ears. When the children were classified as either “with hearing loss—bilateral abnormal ABRs” or “at least one normal ABR”, there was an observed agreement of 81% (κ=0.6; p=0.00). OAEs had a sensitivity of 76.9% (95% CI 66.7–84.8%) and a specificity of 90% (95% CI 75.4–96.7%).

Conclusion There is good concordance between OAE and ABR results among high-risk children referred for hearing screening.     

Auditory evoked potentials in premature and full-term infants

Accurate information about type, degree, and configuration of hearing loss are necessary for successful audiological early interventions. Auditory brainstem response with tone burst stimuli (TB ABR) and auditory steady-state response (ASSR) exams provide this information.AimTo analyze the clinical applicability of TB ABR and ASSR at 2 kHz in infants, comparing responses in full-term and premature neonates.Material and MethodThe study was cross-sectional, clinical and experimental. Subjects consisted of 17 premature infants and 19 full-term infants. TB ABR and ASSR exams at 2000 Hz were done during natural sleep.ResultsThe electrophysiological minimum response obtained with TB ABR was 32.4 dBnHL (52.4 dBSPL); the ASSR minimum was 13.8 dBHL (26.4 dBSPL). The exams required 21.1 min and 22 min, respectively. Premature and full-term infant responses showed no statistically significant differences, except for auditory steady-state response duration.ConclusionsBoth exams have clinical applicability at 2 kHz in infants, with 20 min of duration, on average. In general, there are no differences between premature and full-term individuals.     

脑性瘫痪患儿听性脑干反应及多频稳态听性反应分析

目的：通过听性脑干诱发反应（ABR）及听性稳态反应（ASSR）分析，探讨脑性瘫痪（脑瘫）患儿的听力障碍及脑干听通道功能变化。方法：采用美国GSIAudera听性脑干反应及听性稳态诱发电位测试仪，测试脑瘫患儿52例104耳。对照组为同龄健康儿童19例38耳。结果：脑瘫组患儿的ABR各波潜伏期及峰间潜伏期均较对照组明显延长；脑瘫组ASSR结果以轻度低频听力损失为著，并且各频率听力损失的平均值非常接近。结论：ABR和ASSR同时应用，为脑瘫患儿听力损失进行定性定量诊断提供了客观的测试方法。     

Comparison of threshold estimation in infants with hearing loss or normal hearing using auditory steady-state response evoked by narrow band CE-chirps and auditory brainstem response evoked by tone pips

Objective: The objective of this study is to compare air-conduction thresholds obtained with ASSR evoked by narrow band (NB) CE-chirps and ABR evoked by tone pips (tpABR) in infants with various degrees of hearing loss. Design: Thresholds were measured at 500, 1000, 2000 and 4000?Hz. Data on each participant were collected at the same day. Study sample: Sixty-seven infants aged 4 d to 22 months (median age?=?96 days), resulting in 57, 52, 87 and 56 ears for 500, 1000, 2000 and 4000?Hz, respectively. Results: Statistical analysis was performed for ears with hearing loss (HL) and showed a very strong correlation between tpABR and ASSR evoked by NB CE-chirps: 0.90 (n?=?28), 0.90 (n?=?28), 0.96 (n?=?42) and 0.95 (n?=?30) for 500, 1000, 2000 and 4000?Hz, respectively. At these frequencies, the mean difference between tpABR and ASSR was ?3.6?dB (±?7.0), ?5.2?dB (±?7.3), ?3.9?dB (±?5.2) and ?5.2?dB (±?4.7). Linear regression analysis indicated that the relationship was not influenced by the degree of hearing loss. Conclusion: We propose that dB nHL to dB eHL correction values for ASSR evoked by NB CE-chirps should be 5?dB lower than values used for tpABR.     

Interpreting auditory brainstem evoked responses and distortion product otoacoustic emissions in diabetic patients with normal hearing

ObjectiveHearing impairment is a reported late complication of diabetes mellitus (DM). Previous studies have suggested that microangiopathic complications may cause cochlear nerve function deterioration. We evaluated the auditory brainstem evoked responses (ABRs) and distortion product otoacoustic emission (DPOAE) results according to the presence of DM in subjects with normal hearing.MethodsA cross-sectional comparative study was conducted from January 2016 to January 2018. Auditory function tests including ABR and DPOAE were performed for outpatients complaining of unilateral tinnitus. All of analyses were conducted in ears without tinnitus on contralateral side of tinnitus ears. We included subjects showing hearing thresholds within 25 dB at 0.5, 1k, 2k, and 4k on pure tone audiometry. 45 ears in patients with type 2 diabetes mellitus and 85 ears in non-diabetic patients were finally enrolled in our study.ResultsDiabetic subjects showed significantly more prolonged absolute peak latencies (I, III, V) and inter-peak latencies (I–V, III–V) than non-diabetic subjects. However, there was no significant difference in the inter-peak latency (I–III) between these two groups. Diabetic subjects also showed significantly lower amplitudes at f2 frequencies of 1001, 1200, 1587, 4004, 5042, and 6348 Hz than non-diabetic subjects. Additionally, the prevalence of a DPOAE response, defined as 3 dB above the noise floor, was significantly lower in diabetic subjects than that in non-diabetic subjects.ConclusionDiabetic patients with normal hearing can still have abnormal ABR and DPOAE results due to diabetic neuroangiopathy. ABR and DPOAE assessments can help in detecting subclinical auditory dysfunction, which precedes the manifestation of hearing impairment in diabetic patients.     

小儿蜗后听觉神经损害的临床与听力学特征及定位

目的 探讨包含了听神经病在内的ABR严重异常、DPOAE正常为特征的蜗后听觉神经功能障碍小儿的临床与听力学特征及其可能的病损部位.方法 选取2002至2006年听力专科中ABR严重异常、DPOAE正常,排除中耳传导功能异常的患儿86例(165耳),年龄8 d～7岁,平均1岁1个月,入选为本研究对象.选择ABR严重异常、DPOAE异常、排除中耳病变的听功能障碍26例(29耳)患儿作为蜗性病变对照组,选择健康同龄儿童86例(166耳)作为正常对照组,比较蜗后病变、蜗性病变、正常听力3组间ABR波Ⅰ、波Ⅲ、波Ⅴ潜伏期和振幅,以及Ⅰ～Ⅲ波间期等参数的异同.所有数据采用SPSS11.0统计软件包进行t检验.结果 86例蜗后听神经损害患儿中,51例(59.3%)的病例新生儿期有高胆红素血症史,其中40例血中间接胆红素水平达重度标准,11例为轻中度;在首次就诊的原因中,主诉运动障碍者40例(46.5%),听力言语障碍者10例(11.6%);在伴随的疾病中,32例(37.2%)确诊伴随有脑性瘫痪.在86例165耳蜗后听觉神经功能障碍患耳中,103耳最大强度声刺激(103 dB)ABR无波分化,27耳仅见波Ⅰ分化,19耳仅见波Ⅴ分化,13耳见波Ⅰ+Ⅲ分化,3耳见波Ⅰ+Ⅴ分化.仅见波Ⅰ分化耳,其波Ⅰ潜伏期较正常听力耳延长,振幅较正常听力耳低矮(t值分别为-6.75和2.58,P值均<0.05);有波Ⅰ+Ⅲ分化耳,波Ⅰ潜伏期和振幅与正常听力耳差异无统计学意义,波Ⅲ潜伏期则较正常听力耳延长,振幅较正常听力耳低矮(t值分别为-2.77和3.63,P值均<0.05),Ⅰ～Ⅲ波间期较正常听力耳Ⅰ～Ⅲ波间期延长(t=-2.99,P<0.05).结论 在蜗后听觉神经功能损害类型中,最常见的类型为ABR从波Ⅰ开始就严重异常,即听神经病,其病变主要在第Ⅷ颅神经听支;仅见波Ⅰ分化耳,其病变部位主要在第Ⅷ颅神经听支以后;ABR有波Ⅰ+波Ⅲ分化耳,主要病变部位在波Ⅲ的发源神经核团,即上橄榄核以后的听觉神经通路.振幅低矮的波Ⅴ不是听神经病独有的特征.高胆红素血症导致的蜗后听觉神经系统病变的病例中,其受侵害部位的先后次序可能为大脑皮层、腩干听觉神经核团、第Ⅷ对颅神经听支.     

Auditory brainstem,middle and late latency responses to short gaps in noise at different presentation rates

Objective: The effects of rate on auditory-evoked potentials (AEP) to short noise gaps (12?ms) recorded at high sampling rates using wide-band filters were investigated. Design: Auditory brainstem (ABR), middle latency (MLR), late latency (LLR) and steady-state (ASSR) responses were simultaneously recorded in adult subjects at four gap rates (0.5, 1, 5 and 40?Hz). Major components (V, Na, Pa, Nb, Pb, N1 and P2) were identified at each rate and analysed for latency/amplitude characteristics. Gap responses at 40?Hz were recovered from Quasi-ASSRs (QASSR) using the CLAD deconvolution method. Study Sample: Fourteen right ears of young normal hearing subjects were tested. Results: All major components were present in all subjects at 1?Hz. P1 (P50) appeared as a low-pass filtered component of Pa and Pb waves. At higher rates, N1 and P2 disappeared completely while major ABR-MLR components were identified. Peak latencies were mostly determined by noise onsets slightly delayed by offset responses. Conclusions: Major AEP components can be recorded to short gaps at 1?Hz using high sampling rates and wide-band filters. At higher rates, only ABR and MLRs can be recorded. Such simultaneous recordings may provide a complete assessment of temporal resolution and processing at different levels of auditory pathways.