多频稳态诱发电位评估中度感音神经性聋儿童的应用

目的探讨多频稳态听觉诱发电位评估儿童中度感音神经性聋的可靠性。方法所有患者经纯音测听（PTA）检查筛选出中度感音神经性聋30例5～6岁儿童（共40耳），然后口服10％水合氯醛镇静睡眠后，行多频稳态听觉诱发电位（ASSR）检测，其阈值与纯音听阂阈值进行比较，分析不同频率处听力阈值分布情况及其相关性。结果分别比较语言频率ASSR阂值与纯音听闽阈值，结果显示，0．5kHz处相关性较差，其差值为2-18dB，而在4kHz处相关性最好。结论可以应用多频稳态听觉诱发电位评估中度感音神经性聋儿童的听力阈值，但需要注意0．5kHz处的相关性差异。     

Auditory steady-state responses for estimating moderate hearing loss

The auditory steady-state response (ASSR) has gained popularity as an alternative technique for objective audiometry but its use in less severe degrees of hearing loss has been questioned. The aim of this study was to investigate the usefulness of the ASSR in estimating moderate degrees of hearing loss. Seven subjects (12 ears) with moderate sensorineural hearing loss between 15 and 18 years of age were enrolled in the study. Forty-eight behavioural and ASSR thresholds were obtained across the frequencies of 0.5, 1, 2, and 4 kHz. ASSR thresholds were determined using a dichotic multiple frequency recording technique. Mean threshold differences varied between 2 and 8 dB (±7–10 dB SD) across frequencies. The highest difference and variability was recorded at 0.5 kHz. The frequencies 1–4 kHz also revealed significantly better correlations (0.74–0.88) compared to 0.5 kHz (0.31). Comparing correlation coefficients for behavioural thresholds less than 60 and 60 dB and higher revealed a significant difference. Eighty-six percent of ASSR thresholds corresponded within 5 dB of moderate to severe behavioural thresholds compared to only 29% for mild to moderate thresholds in this study. The results confirm that the ASSR can reliably estimate behavioural thresholds of 60 dB and higher, but due to increased variability, caution is recommended when estimating behavioural thresholds of less than 60 dB, especially at 0.5 kHz.     

Comparison of auditory steady-state responses and auditory brainstem responses in audiometric assessment of adults with sensorineural hearing loss

Objective

Many of the medico-legal patients who claimed compensation may exaggerate hearing loss that varies in degree, nature, and laterality. The purpose of this study was to investigate whether Auditory Steady-State Response (ASSR) could be used to predict the hearing level of adults, and whether ASSR could become a better testing method than Auditory brainstem response (ABR) in audiometric assessment of adults with sensorineural hearing loss.

Methods

This was a prospective study, which was conducted in a tertiary referral hospital. From January to June 2007, 142 subjects (284 ears) with varying degrees of sensori-neural hearing impairment were included in this study. Four commonly used frequencies (500, 1000, 2000, 4000 Hz) were evaluated. All subjects received pure-tone audiometry, multi-channel ASSR, and ABR tests for threshold measurement. The correlation of pure tone thresholds with ASSR and ABR thresholds were assessed.

Results

Between multi-channel ASSR and pure tone thresholds, a difference of less than 15 dB was found in 71% while a difference of less than 25 dB was found in 89% of patients. The correlation coefficient (r) of multi-channel ASSR and pure tone thresholds were 0.89, 0.95, 0.96, and 0.97 at 500, 1000, 2000, and 4000 Hz, respectively. The strength of the relationship increased with increasing frequency. On the other hand, between ABR and pure-tone thresholds, a difference of less than 15 dB was found in 31%; a difference of less than 25 dB was found in 62% of patients. The r correlation value for ABR and pure tone thresholds was 0.83.

Conclusion

ASSR is a more reliable test for the accurate prediction of auditory thresholds than ABR. It can be a powerful and convenient electro-physiologic examination tool for clinically assessing of adults with sensorineural hearing loss.     

Auditory steady-state responses and clinical applications

The auditory steady-state responses to single continuous tones modulated in amplitude have been proposed as an alternative to objective frequency-specific audiometry. The aim of this study was to compare thresholds obtained by pure-tone audiometry (PTA) and by auditory steady-state responses in normal hearing or affected by hearing loss in adults and in order to evaluate the applicability of this objective test in no collaborative hearing-impaired subjects. Eleven people, 6 normal hearing and 5 with hearing loss, underwent PTA and multiple frequency auditory steady-state responses; simultaneous carrier tones (0.5, 1, 2 and 4 KHz) modulated in amplitude at different rates (77–105 Hz) were presented monaurally (TDH 49 earphones) at variable intensities (110–20 dB SPL). The mean threshold difference between PTA and multiple frequency auditory steady-state responses was 28 dB (standard deviation=14.2) and R correlation value at 0.5-1-2-4 kHz was 0.71 (P=0.0012) at the Pearson’s test. These differences were significantly smaller considering the hearing-impaired separately (11.7 dB, standard deviation=2.9). The results of this study confirm previous reports showing that the multiple auditory steady-state response method is an accurate predictor of the behavioural audiogram in patients with sensory-neural hearing impairments and can be used as a valid support for behavioural evaluations.     

Auditory evoked magnetic fields in children with functional hearing loss

Objectives

Abnormal cortical responses in patients with functional hearing loss were evaluated by magnetoencephalography, which can better separate bihemispherical activity than electroencephalography.

Methods

Auditory evoked fields in response to 1 kHz or 2 kHz tone bursts at 80 dB sound pressure level were measured by a helmet-shaped magnetoencephalography system in 22 patients with functional hearing loss (18 females, mean age 13.2 years) as well as 5 control subjects under 10 years old. Waveform, latency, and equivalent current dipole of N100m responses were used to evaluate activity in the bilateral auditory cortices.

Results

Abnormal N100m of the contralateral response to the stimulated ear, either absence or delayed latency in comparison to normal adult subjects, was found in 6 of the 7 patients with functional hearing loss aged 9 years or younger, but in only 3 of the 15 patients aged 10 years or older. However, such abnormalities were also observed in younger control subjects.

Conclusion

Auditory evoked field may be applied to objectively evaluate cortical auditory function in patients with functional hearing loss, but the normal findings for young children have not yet been established.     

同步多频听觉稳态诱发反应在小儿听力诊断中的应用

目的　探讨同步多频听觉稳态诱发反应在小儿听力诊断中的应用。方法　39例受试者,年龄6个月～5岁,平均2.75岁,男21例,女18例。分别进行同步多频听觉稳态诱发反应和小儿行为听力测试。同步多频听觉稳态诱发反应刺激声信号的载波频率为0.5 kHz 、1 kHz 、2 kHz及4kHz。双耳上述各个频率分别以70～100 Hz不同的调制频率进行调幅调制。测试时,双耳八个(每耳四个)声信号经ER-3A插入式耳机同步给出。测试状态为水合氯醛镇静睡眠。小儿行为听力测试中,6～24月龄小儿行视觉强化定向条件反应测听、25月龄～5岁行游戏测听。所有数据以SPSS统计软件分析。结果　①小儿行为听阈通常比同步多频听觉稳态诱发反应阈低,在0.5kHz、1kHz 、2kHz及4kHz二者差异的平均值及标准差分别为:15.2±9.1dB、8.8 ±7.5dB、8.2±7.7dB、10.7±8.8dB。各个频率之间这一差异存在统计学意义(F =10.395;μ 3 ;P=0.000),进一步的两两比较显示0.5 kHz行为听阈与反应阈的差异高于其它频率;②小儿行为听阈与同步多频听觉稳态诱发反应阈在各个频率均呈显著相关(P =0.000)。Pearson相关系数分别为0.799,0.859,0.894,0.850。结论　同步多频听觉稳态诱发反应测试具有频率特异性、客观及与行为听阈相关性好的特点,可以作为无法配合行为听力测试的小     

Auditory steady-state response and auditory brainstem response thresholds in children

The inclusion of the auditory steady-state response (ASSR) into test-batteries for objective audiometry has allowed for clinical comparisons with the most widely used procedure, the auditory brainstem response (ABR). The current study describes ASSR and ABR thresholds for a group of infants and young children with various types and degrees of hearing loss. A sample of 48 subjects (23 female) with a mean age of 2.8 ± 1.9 years SD were assessed with a comprehensive test-battery and classified according to type and degree of hearing loss. Thresholds were determined with a broadband click-evoked ABR and single frequency ASSR evoked with continuous tones (0.25–4 kHz) amplitude modulated (67–95 Hz). Mean difference scores (±SD) between the ABR and high frequency ASSR thresholds were 9.8 (±11), 3.6 (±12) and 10.5 (±12) dB at 1, 2 and 4 kHz, respectively. An ASSR mean threshold for 2–4 and 1–4 kHz compared to the ABR threshold revealed an average difference of 7 (±9) and 7.9 (±8) dB, respectively. The overall correlation between the ABR and ASSR thresholds was highest for the mean ASSR thresholds of 2–4 and 1–4 kHz (r = 0.92 for both conditions). Correlations between the ABR and individual ASSR frequencies were slightly less (0.82–0.86). The average of the 2–4 kHz ASSR thresholds correlated best with the click-evoked ABR for all categories of hearing loss except for the sensorineural hearing loss category for which the 1–4 kHz ASSR average was better correlated to ABR thresholds. Findings demonstrate the reliability of verifying high frequency ASSR thresholds with a click-evoked ABR as an important cross-check in infants for whom behavioural audiometry may not be possible.     

多频稳态诱发电位和听性脑干反应对感音神经性聋儿童客观听阈的评估

目的比较多频稳态诱发电位(MASSR)与短纯音听性脑干反应(Tb-ABR)对感音神经性聋儿童客观听阈的评估。方法对37名感音神经性聋儿童分别测试MASSR反应阈、Tb-ABR反应阈和行为听阈,参照行为听阈,比较MASSR反应阈和Tb ABR反应阈对行为听阈评估的准确性。结果MASSR反应阈、Tb-ABR反应阈和行为听阈之间均有较高的相关性。二者在频率为2、4kHz时,对行为听阈的评估具有相似的准确性;但在频率为0.5、1kHz时,MASSR的准确性较Tb ABR的准确性高。结论MASSR和Tb-ABR均可用作感音神经性聋儿童言语频率客观听阈的评估,但MASSR在低频(0.5、1kHz)时较Tb-ABR的准确性高。     

Maturation of bone conduction multiple auditory steady-state responses

The objective of this study was to compare bone-conduction (BC) auditory steady-state responses (ASSR) for infants and adults with normal hearing to investigate the time course of maturation of BC hearing sensitivity. Bone-conduction multiple ASSRs were recorded in 0–11-month-old (n=35), and 12–24-month-old infants (n=13), and adults (n=18). Low-frequency BC ASSR thresholds increased with age, whereas, high-frequency ASSR thresholds were unaffected by age except for a slight improvement at 2000Hz. Compared to adults, BC ASSR amplitudes for young infants were larger for low frequencies, whereas, their amplitudes were smaller or similar for high frequencies. Compared to adults, young infants are much more sensitive to low-frequency BC stimuli, and probably more sensitive to high-frequency BC stimuli; these differences between infants and adults persist until at least two years of age. Different ‘normal levels’ for infants of different ages must be used and are proposed in this study.     

Aided auditory steady-state responses in infants

Infants with hearing loss routinely receive hearing aids several months before reliable behavioral responses to amplified sound can be observed. This necessitates objective measures to validate hearing-aid fittings. A single report has demonstrated the use of ASSRs to determine aided thresholds in children but data in young infants is still lacking. The current study explored aided ASSR compared to unaided ASSR thresholds and subsequent behavioral thresholds in a group of six young infants with hearing loss who received hearing aids between three and six months of age. Aided ASSR thresholds were obtained in 83% of frequencies where aided behavioral thresholds were obtained, with a mean threshold difference of 13±13 dB. The aided ASSR-based threshold estimates were within 15 dB of behavioral thresholds in 63% of cases, indicating a moderate correlation (r = 0.55). Comparing aided and unaided ASSR measurements revealed an average functional gain of 36±15 dB. These results indicate that ASSRs can provide the first evidence of robust hearing aid benefit in young infants several months before behavioral responses are observed.     

Epileptiform electroencephalogram abnormality in children with congenital sensorineural hearing loss

Objectives

This work was designed to study electroencephalogram findings in children with congenital sensorineural hearing loss and correlate these findings with the SNHL parameters as duration, etiology, severity, and type.

Methods

Ninety children with bilateral congenital sensorineural hearing loss served as the study group. They were free from any neurological disorders or symptoms that are commonly associated with abnormal electroencephalogram as convulsions or loss of consciousness. Twenty children having normal hearing with no history of otological or neurological disorders served as the control group. All children participating in the study were subjected to full medical and audiological history, otological examination, neurological examination, audiological evaluation and electroencephalogram recording.

Results

Mean age of the children in the control group was 3.56 ± 2.1 years and mean age of the children in the study group was 3.8 ± 2.2 years. While none of the control children had abnormal electroencephalogram, 38 (42.2%) of children with congenital SNHL had epileptiform electroencephalogram abnormality. The epileptiform abnormality was generalized in 14 children (36.8%), focal temporal in 17 children (44.7%) and focal other than temporal in 7 children (18.4%). According to the hemispheric side affected, the abnormality was right in 14 children (36.8%), left in 10 children (26.3%) and bilateral in 14 children (36.8%). No statistically significant predominance of specific site or side of the epileptiform abnormality was found. Similarly, no statistical significant prevalent of the epileptiform abnormality was found in relation to the age or sex of children, duration of hearing loss or etiology of hearing loss (i.e., genetic vs. neonatal insults). On the other hand, the epileptiform abnormality was statistically prevalent in children with moderate degree of hearing loss, and in children with auditory neuropathy spectrum disorder.

Conclusions

The epileptiform electroencephalogram abnormality is a common finding in children with congenital sensorineural hearing loss especially those with auditory neuropathy spectrum disorder, suggesting the affection of the central nervous system despite the absence of neurological symptoms or signs. These findings raise the question of the requirement of medical treatment for those children and the effect of such treatment in their rehabilitation.     

感音神经性聋儿多频稳态诱发电位及短纯音听性脑干反应与行为测听的相关性

目的 比较多频稳态诱发电位（MASSR）、短纯音听性脑干反应（Tb—ABR）与感音神经性聋儿行为测试听阈的差值．研究MASSR和Tb—ABR反应阈与行为听阈之间是否存在相关性以及在不同听力损失聋儿、不同的频率之间的差异。方法 对60名感音神经性聋儿分别测试MASSR和Tb—ABR反应阈和行为听阈，评价MASSR反应阈、Tb—ABR反应阈与行为听阈的相关性。结果 MASSR反应阈、Tb—ABR反应阈和行为听阈之间均有较高的相关性。二者在频率为2、4kHz时，对行为听阈的预测具有相似的、较高的准确性；但在频率为0．5、1kHz时，MASSR的准确性较Tb—ABR高。结论 MASSR和Tb—ABR均可用作感音神经性聋儿言语频率客观听阈的预测，为低龄儿童及难以检测行为听力的患儿提供诊断依据。     

Threshold prediction in children with sensorioneural hearing loss using the auditory steady-state responses and tone-evoked auditory brain stem response

Objective

The purpose of this study was to compare ASSRs to tone-evoked ABR and to behavioral thresholds obtained on follow-up audiometry at 500, 1000, 2000, and 4000 Hz in infants and young children.

Methods

The study included 17 infants and young children ages between 2 months and 3 years old, with sensorineural hearing loss. The ASSRs thresholds were compared with the tone-evoked ABR thresholds, and with the behavioral thresholds obtained on follow-up audiometry.

Results

The correlation of tone-evoked ABR and ASSRs thresholds at 500, 1000, 2000 and 4000 Hz was 0.91, 0.76, 0.81, 0.89, respectively. ASSRs and behavioral hearing thresholds obtained on follow-up were highly correlated, with Pearson r values exceeding 0.94 at each of the test frequencies.

Conclusions

Multiple ASSRs have strong correlations to tone-evoked ABR and to behavioral thresholds obtained during follow-up in hearing impaired infants and young children. These results might be useful in order to provide further evidence for the use of multiple ASSRs, as an alternative tool to tone-evoked ABR, although further data are still required.     

突发性聋患者听觉中枢在功能性核磁的表现

目的 利用血氧水平依赖性的功能性磁共振成像（blood oxygen level dependent functional MRI,BOLD～fMRD技术,观察突发性聋患者在接受纯音刺激时听觉中枢的变化。方法研究对象分为两组,突发性聋患者13例（均为左耳患病）为试验组,12例双耳听力正常的健康成年志愿者作为对照组。通过CoolEditPr02软件编辑1000Hz、127dB纯音,刺激模式采用ON／OFF组块设计,通过耳机分别给予右耳及双耳音频刺激,采用荷兰Philips Achieva3．0T磁共振成像系统,采集脑部的BOLD—fMRI数据,最后通过SPM2软件对数据进行统计学分析（组分析）,得到脑功能活动的图像。结果右耳接受纯音刺激时听力正常组主要中枢激活区在双侧颞上回、左枕叶、左额上回,此外还有左小脑、双侧海马及双侧旁中央小叶激活,听觉中枢表现为右侧优势偏向;突聋组见双侧颞上回,以及左侧海马、右枕叶和左侧距状裂区激活,听觉中枢表现为左侧优势偏向,突聋组听中枢激活容积小于正常组。双耳同时刺激时,听力正常组激活区主要在双侧颞中回,右侧扣带回和左胼胝体亦明显激活;突聋组双侧颞中回,以及右侧颞上回、右小脑、右侧额下回及右楔前叶激活,两组听觉中枢均表现为右侧优势偏向。听力正常组与突聋组比较,正常组左小脑、左胼胝体区明显激活,突聋组出现新的激活区右侧颞上回、右侧额下回及右小脑区：突聋组听中枢激活容积小于正常组。结论突聋患者在单耳刺激时听觉中枢出现优势偏向的改变,提示单侧耳聋的病人听觉皮质存在着结构重组;听觉中枢具有可塑性。突聋患者在双侧刺激时通过听觉重组使双耳对外界声音的感知尽量达到正常水平;突聋患者听觉中枢不仅本身存在重组现象,且同视觉皮质之间也发生了感觉交互作用。     

The latency of auditory nerve-brainstem responses in sensorineural hearing loss

Summary The use of auditory nerve-brainstem responses in differential diagnosis of hearing loss is based on several properties of these responses including response latency. The auditory nerve response latency has been shown to be prolonged in conductive hearing loss. The latency of the brainstem responses is also often prolonged in retrocochlear hearing loss. However, the effect of sensorineural hearing losses on auditory nerve response latency is not clear. Several authors report that response latency is prolonged in sensorineural loss, whereas others claim that it is unchanged.To study this, auditory nerve-brainstem responses to 75 dB HL clicks were recorded in normal-hearing subjects and in those with various degrees of high-frequency sensorineural hearing loss. In the more extreme hearing losses, the auditory nerve response could not be seen in the response trace, so the latency of the earlobe positive wave from the region of the inferior colliculus was considered as mirroring auditory nerve response latency, since the time interval between these two waves has been shown to be constant.The average latency of the more severe hearing loss group (more than 40 dB hearing loss at 4 kHz) was found to be only 0.35 ms longer than that of the normal-hearing group. This value is smaller than that seen in most conductive and retrocochlear hearing losses.This result warrants continued use of prolonged auditory nerve response latency (greater than 0.35 ms) as an indicator of conductive hearing loss. Possible explanations for smaller latency prolongation than expected of the auditory nerve response in sensorineural hearing loss are discussed based on the properties of single auditory nerve fibers.Part of a PhD thesis to be submitted by R. Kinarti to the Senate of the Tel-Aviv Universtity     

Estimating audiometric thresholds using simultaneous acquisition of ASSR and ABR from QASSR in patients with sensorineural hearing loss

Objectives: To evaluate the accuracy with which the innovative QASSR method predicts behavioral thresholds in adult patients with sensorineural hearing loss. Design: Subjects were tested at four carrier frequencies (500, 1000, 2000, and 4000?Hz).The resulting QASSR recordings were analyzed for thresholds and magnitude/phase characteristics. Tone-burst ABR was recovered from QASSR signal using CLAD method and analyzed in the time domain. The electrophysiological estimates were compared to hearing thresholds determined behaviorally. Study sample: Sixteen ears of nine volunteer subjects recruited from a clinical population. Results: All mean threshold estimates differed less than 3?dB for QASSR and less than 5?dB for ABR at 1000, 2000 and 4000Hz (carrier or pure-tone test frequencies). The largest differences were observed for both at 500?Hz (5.63 and 11.56?dB respectively).The audiometric configurations of QASSR and ABR estimates followed those of the respective behaviorally determined configurations across ears tested. Conclusions: QASSR method merges two dissimilar stimulation techniques, transient and steady-state, to create a hybrid stimulation-and-analysis paradigm that seems to improve the overall performance of the electrophysiological threshold estimation. The unique feature of the QASSR technique is the additional information afforded by the transient ABR, recovered from the same recording. The QASSR thus holds promise to be a very useful tool for practical clinical applications.     

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.     

成人感音神经性聋的听觉稳态反应反应阈与纯音听阈

目的探讨成人感音神经性聋的听觉稳态反应（auditory steady-state responses,ASSR）反应阈与纯音听阈的关系。方法选择中国医科大学附属一院耳鼻咽喉科门诊感音神经性聋的成人患者,分别进行纯音听力测试、ASSR检查,比较ASSR在0.5、1、2、4 kHz频率处的反应阈与纯音听阈的相关性及按听力损失程度比较两者的差值。结果 ASSR反应阈与纯音听阈在各频率处的相关系数分别为0.840、0.905、0.886、0.924;随着感音神经性听力损失的加重二者的差值明显缩小。随着频率的增加,两者的差值明显缩小。结论成人感音神经性聋ASSR反应阈与纯音听阈有显著相关性,随着听力损失的加重,ASSR反应阈愈接近纯音听阈,ASSR作为成人感音神经性聋听力定量诊断的客观方法有很大的临床应用价值。     

骨导多频听觉稳态诱发反应的测试

目的：了解多频听觉稳态诱发反应（MASSR）对骨导客观听阈及对传导性聋评估的准确性。方法：对30例传导性聋患者进行气、骨导MASSR及纯音测听,并将MASSR反应阈和纯音听阈进行比较。结果：气、骨导MASSR反应阈和纯音听阈之间具有较好的相关性,MASSR对传导性聋评估的准确性和纯音测听相似。结论：MASSR可用作传导性聋患者客观听阈的评估。