全身麻醉对小儿听性脑干反应测试结果的影响

目的 研究应用听性脑干反应(auditory brainstem reaction，ABR)作为监测小儿全身麻醉深度与觉醒的客观指标。方法 选择听力正常的外科择期手术患儿45例，按照美国麻醉学家学会表针分为I～Ⅱ级，分别施行异丙酚静脉麻醉、芬太尼静脉麻醉及异氟醚吸入全身麻醉，随机每组15例，应用丹麦Madsen诱发电位反应仪监测并记录麻醉各阶段ABR的I、Ⅲ、Ⅴ波潜伏期及I-Ⅲ、Ⅲ-Ⅴ、I-Ⅴ波间期，研究观察潜伏期和波间期随时间推移及麻醉剂量变化之间的关系，探讨ABR在异丙酚、芬太尼及异氟醚等不同麻醉中的表现特征和规律。结果 ①异丙酚静脉麻醉和异氟醚吸入麻醉与剂量呈良好的正相关；②I波的潜伏期特性对于控制麻醉深度极为重要；③Ⅴ波监测麻醉具有最佳的稳定性及相关性；④停用麻醉药一段时间或患儿基本清醒时，ABR各波潜伏期和波间期有的仍高于正常值，这是滞后(延迟)反应；⑤ABR对芬太尼术中的觉醒监测不太敏感。结论 ABR各波的潜伏期及波间期变化，可判断小儿全身麻醉深度，在一定程度上可作为判断觉醒的参考，但应考虑有延迟反应的可能。     

Autism and auditory brain stem responses

OBJECTIVE: To study a controversy that has been discussed for more than two decades: whether or not children with autism have abnormalities affecting the cochlear nerve or the auditory pathway in the brain stem and, if so, to describe these abnormalities. DESIGN: A group of 153 children and adolescents with autistic disorder were included in an investigation of auditory brain stem responses (ABR). Two thirds of this group, 101 individuals (75 boys, 26 girls), had normal hearing and they were selected for an in-depth ABR study. The results from the study group were compared with those of an age-matched comparison group. RESULTS: The III-V interpeak latency (IPL) was significantly prolonged in both boys and girls with autism, compared with the controls. The latencies of ABR waves I and V were also significantly lengthened in the study groups. The individual test results showed that more than half of this normal-hearing autistic disorder group (58%) had abnormalities of one or more of eight ABR parameters studied. The most common abnormalities were prolongation of wave V (38%), and of I-V IPL (28%). A lengthening of the I-V IPL was also recorded in 27% of 49 children who were difficult to test or who had hearing loss. Abnormal left-right differences of ABR latencies were found in 18% of autism cases with normal hearing. CONCLUSIONS: Possible causes of the reported ABR abnormalities, observed here as well as in other studies, are discussed. Brain stem lesion, occult cochlear dysfunction, and involvement of the cochlear efferent system are probable factors that can explain the ABR findings     

The relative importance of head size, gender and age on the auditory brainstem response

Correlations between the ABR (auditory brainstem response) and subject characteristics of gender, age, and head diameter were established in simple and multiple regression analyses of normal hearing individuals. The simple regression tests demonstrated that head diameter and gender were significantly correlated with the latencies and amplitudes of waves I, III, and V and the I-V and III-V interpeak intervals. In nearly all cases, head diameter correlated more highly with the ABR waves than did gender. Males had longer latencies than females with comparable head diameter, suggesting that factors other than head size are differentiating them. Age was significantly correlated only with the latency of wave III. All significant subject variables also were compared simultaneously in a multiple regression analysis to determine their order of significance and relative contributions to the ABR wave latencies. This permitted the establishment of regression equations for each wave latency to predict the ABR with measurable subject characteristics.     

Auditory brainstem response in pediatric migraine: during the attack and asymptomatic period

OBJECTIVE: The aim of this study was to evaluate the hearing parameters of children with migraine during ictal and interictal period. METHOD: 16 pediatric patients with migraine and normal otolaryngologic examination were evaluated. Hearing parameters were assessed with auditory brainstem response (ABR) testing between and during the migraine attacks. Binaural absolute latencies of waves I, III and V, interpeak latencies I-III, III-V and I-V of ABR in response to 80 dB nHL clicks were calculated. Initial findings were compared with those of 20 healthy volunteers. RESULTS: Peak latencies of wave V and interpeak latencies of I-V were prolonged during the attack in migraineurs on the left. The side of latency elongation was not affected by the side of headache. When these parameters were separately compared for gender, they were prolonged in boys during the attack in migraineurs; however in girls, while there was statistically significant difference at interpeak latencies of I-V, no significant difference was noted at peak latencies of wave V. CONCLUSIONS: ABR waves did not exceed clinical norms in migraine patients in headache-free period. But, important effects on sensorineural hearing parameters were detected during the attack. Our results indicated a transient impairment of the auditory brainstem function during the headache in pediatric migraine patients.     

高刺激速率听性脑干反应实验室正常参考值研究*

目的获得正常青年的高刺激速率(high stimulus rate)听性脑干反应(ABR)实验室正常参考值范围并分析其特点,为诊断后循环缺血提供参考依据.方法对20例听力正常青年(男女各10例,共40耳)分别进行刺激速率为11.1次/s和51.1次/s的ABR检测,比较两种不同刺激速率下I、III、V波的潜伏期(peak latency,PL),I~III、III~V、I~V波间期(inter-peak latency,IPL)和波间期的差值(ΔIPL),并对测试的结果进行统计分析.结果刺激速率为11.1次/s时波I、III、V的PL分别为1.33±0.07、3.57±0.18、5.51±0.23 ms;I~III、III~V、I~V的IPL分别为2.25±0.19、1.93±0.16、4.18±0.21 ms.刺激速率为51.1次/s时波I、III、V的PL分别为1.44±0.06、3.74±0.16、5.80±0.18 ms;I~III、III~V、I~V的IPL分别为2.31±0.14、2.06±0.12、4.36±0.17 ms.高低刺激速率下I~III、III~V、I~V的ΔIPL分别为0.06±0.08、0.13±0.10、0.18±0.09 ms.不同刺激速率下I~V的ΔIPL实验室正常参考值范围为△I~V<0.328 ms.结论随刺激声速率升高,ABR各波PL、IPL、ΔIPL均会延长.本文提出了听力正常的青年人不同刺激速率下ABR各波潜伏期、波间期和I~V波间期差值的实验室正常参考值范围,为后循环缺血患者的早期诊断提供参考依据.     

Effects of gender and head size on the auditory brainstem response

Fifty audiologically normal young adults, 25 men and 25 women, were submitted to the auditory brainstem response (ABR) test. The mean latencies of the waves I, II, III, IV and V and the interpeak latencies (IPLs) I-III, I-V and III-V were calculated and compared to the normative values published by other groups. We have observed a great similarity among these values, specially in the interpeak latencies. The latencies of the principal ABR parameters were compared between the sexes showing significant differences in all the waves, particularly in the wave V. No significant correlations were found among the values when the head size and the ABR principal components latencies were confronted.     

Effects of age and sex on auditory brain stem response. A new aspect

The age and sex dependence of the latencies and interpeak intervals (IPI) of the auditory brain stem response (ABR) was investigated in 86 males and 69 females. The latencies of the waves I, III and V as well as the IPI I-V and III-V are significantly shorter in females than in males. A correlative linear dependence on age could be shown for the latencies of waves I, III and V in males and for the wave V latency in females. The slopes of the regression lines calculated for the dependence of ABR latencies I, III and V on age tend to be steeper in males than in females. The slope increases from wave I to wave V. The male and female regression lines intersect the latency axis at about the same point (at the same latency value at age A = O). On the basis of these results, the hypothesis is established, that age and sex dependence is not caused by different mechanisms. The ABR latency differences between males and females are in the main the result of the ABR age dependence being less pronounced in females than in males.     

Pentoxifylline response in alloxan-induced diabetic rats

Conclusion. This study in rats shows that pentoxifylline may reverse detrimental effects of diabetes mellitus (DM) on the auditory system. Objective. To investigate whether delayed auditory brainstem responses (ABRs) induced by DM improve following pentoxifylline treatment in rats. Materials and methods. Baseline ABRs were recorded in 25 ears of 13 normal-hearing rats. DM was induced by a single injection of alloxan (75 mg/kg of body weight) in all rats. Following a 1-month diabetic period, ABRs were recorded in six diabetic rats. Then, pentoxifylline treatment was administered for 6 weeks (20 mg/kg in drinking water), and final ABR testing was performed. Absolute latencies of waves I, III and V, and inter-peak latency differences (IPL) of I–V were measured in each stage of the experiment. These parameters were compared to each other in a pair-wise manner. Results. All wave latencies and IPL I–V were prolonged following induction of DM. Delay in waves III and V, and IPL I–V was significant (p<0.05). Pentoxifylline improved all of the wave latencies and IPL I–V, but significant improvement was observed in waves III and V (p<0.05). There was no significant difference between baseline measurements and measurements following pentoxifylline treatment.     

儿童分泌性中耳炎鼓膜置管前后听性脑干反应的特征

目的：评价儿童分泌性中耳炎鼓膜置管前后听性脑干反应（ABR）的特征及变化。方法：回顾性分析行鼓膜置管的37例分泌性中耳炎患儿（研究组）手术前后的ABR资料,并与30例健康儿童（对照组）的ABR资料相对比;将研究组再按波形分化程度分为波形分化不良组和波形分化较好组,对两组的病程及波Ⅴ反应阈等进行比较。结果：①儿童分泌性中耳炎可以影响ABR的波形分化和各波出现率,手术后有改善;术前波形分化不良组的波Ⅴ反应阈及病程与波形分化较好组相比,差异有统计学意义（P〈0．01或P〈0．05）。②Ⅰ、Ⅲ、Ⅴ波潜伏期术后较术前明显缩短且差异有统计学意义（P〈0．05）,但手术前后波间期的改变无统计学意义。③与对照组相比,手术前后均存在部分波潜伏期及波间期的异常,且有统计学意义。结论：儿童分泌性中耳炎的ABR表现为：波形分化及出现率的改变、波间期及波潜伏期的改变、波Ⅴ反应阈的改变,鼓膜置管术可以改善这些变化,但仍未达到对照组水平。     

Auditory brainstem evoked responses in insulin-dependent (ID) and non-insulin-dependent (NID) diabetic subjects with normal hearing

Hearing impairment has been reported to be one of the late complications of diabetes mellitus (DM), and the frequency varies. Previous data suggest that auditory brainstem potentials deteriorate long before the hearing impairment appears in patients with DM. Delay in neural conductance along the auditory pathway due to DM was assessed by means of auditory brainstem response (ABR) in 43 patients with normal hearing in a controlled study. Patients were classified according to age, presence of neuropathy. metabolic control, and duration and type of DM. ABR recordings revealed that absolute latencies of waves I, III and V were prolonged significantly in the diabetic group when compared to the control group (p < 0.05). When two diabetic groups (insulin-dependent and non-insulin-dependent) were compared with each other, the difference between the latency of wave I and the inter-peak latencies of I-III, III-V and I-V was not significant (p > 0.05). However, the difference between the latencies of waves III and V in the two diabetic groups was statistically significant. The duration of diabetes, blood glucose level and age were not associated with prolonged ABR latencies (p > 0.05). Prolongation of latency of ABR in patients with DM should alert us to possible damage to the auditory nerve, and close follow-up is needed in these patients.     

Auditory brain-stem responses in children with previous otitis media

The auditory brain-stem responses (ABRs) of 18 children who received tympanostomy tubes due to well-documented history of otitis media with effusion (OME) were compared with a matched control group with little or no history of effusion. The subjects in the OME group had significantly longer ABR latencies for waves III and V, with the most compelling delay for wave III and the III-I interwave interval. Although wave I prolongation in the OME group was not significant, the possible contribution of a peripheral effect on the latencies of waves III and V was investigated. The typical gender effect for the ABR latencies was unaltered in the OME group, and there was no group by gender interaction. We suggest that although the data support increased ABR latencies for children with a history of OME, they do not establish a causal relationship.     

Effect of hearing loss of cochlear origin on the auditory brain stem response.

Auditory brain stem response (ABR) testing is widely used to detect lesions of the auditory neural pathways. The ABR waves depend not only on the integrity of the neural pathways, but also on the condition of the cochlea. To properly interpret the ABR response, it is necessary to understand the effects of cochlear hearing loss on the ABR wave latencies. We studied two populations of subjects with cochlear hearing loss: one with varying degrees of high-frequency hearing loss and the other with varying degrees of flat configuration hearing loss. The degree of cochlear hearing loss was quantified in several different ways and subjected to one linear and three nonlinear regression analyses to test for accuracy in predicting ABR wave latencies and interpeak intervals (waves I, III, V, I-V, I-III, and III-V) for three click intensities. Hearing loss levels from 2 to 6 kHz, in particular 4 kHz, were superior to other audiometric test frequencies as predictors of ABR wave latencies for the group with the high-frequency losses. No particular characterization was found to be superior for the flat hearing loss configurations. From these results, modeled predictions of wave latencies as a function of degree and configuration of hearing loss were made. The modeled predictions are then used to suggest guidelines for interpretations of ABR results where hearing impaired patients are involved.     

Maturation of auditory brainstem potentials in neonates and infants

Auditory brainstem evoked potentials (ABP) were recorded in 59 healthy neonates and infants whose age ranged from 3 days to 18 months (6 age groups). Latencies of individual waves and the interpeak latencies (IPL) of I-III, III-V and I-V were analysed. A different maturational pattern was observed in the pontomedullary and the pontomesencephalic segments of the brainstem. Latencies of all waves except wave I were longer in male than in female babies. Establishment of normative data related to the technical variables employed by the individual team is a sine qua non prerequisite for adequate neurological evaluation of ABP.     

Auditory brainstem responses in Rett syndrome: effects of hyperventilation, seizures, and tympanometric variables

This study examined the effects of tympanometric variables, stage of disease, hyperventilation, and seizures on the auditory brainstem response (ABR) in Rett syndrome (RS). Thirty-four female children with RS ranging in age from 2 years, 3 months to 15 years, 7 months participated in the study. ABRs and tympanograms were recorded from all of the subjects. When the ABR peaks were identifiable, interpeak latency intervals (IPLIs) for I-III, III-V, and I-V were computed for each waveform. The peaks (I, III, and V) and IPLIs were characterized as abnormal if either the peaks were absent or the latencies were greater than 2 SD from the normative data (obtained on female children). Analyses revealed significant prolongation of wave I latencies in Rett children with abnormal tympanograms. ABR wave III latencies were significantly affected by the presence of seizures and hyperventilation. The Pearson chi-square statistic revealed significant differences in the rate of wave III and V abnormalities due to the presence and degree of hyperventilation and the presence of seizures. Wave I abnormalities were also observed in the presence of normal middle ear function, suggesting the presence of sensorineural hearing impairment in some RS children. Clinical implications of these findings are discussed.     

Auditory brain stem response throughout the menstrual cycle

A prospective study was performed to evaluate the changes in the auditory brain stem response (ABR) that occur in healthy premenopausal women throughout the menstrual cycle. Ninety-four women with ovulatory menstrual cycles underwent ABR testing by auditory evoked potentials for wave I, III, and V latencies and for interpeak I-III, I-V, and III-V intervals during the follicular, periovular, and luteal phases of the menstrual cycle. The wave latencies and the interpeak intervals showed shorter values during the periovular phase than during the luteal phase (p < .05) and shorter values during the follicular phase for wave I (p < .05) and interpeak interval I-V (p < .05). The ABR seems to be influenced by the variations of ovarian steroids that occur during the menstrual cycle.     

Effects of the acute exposure to the electromagnetic field of mobile phones on human auditory brainstem responses

The purpose of this study was to evaluate the short-term effects of the electromagnetic fields (EMF) of mobile phones on human auditory brainstem responses. This prospective study of healthy adults evaluated the influence of EMF. Eighteen healthy adult volunteers participated in this study. Mobile telephones emitting signals in the region of 900 MHz and with the highest SAR value of 0.82 W/kg were positioned in direct contact to the right ear, which was exposed to the phone signal for 15 min before and after ABR testing with click stimuli of 60 and 80 dB nHL intensities. The latencies of the waves and interwave latencies were measured on screen by an experienced audiologist. The differences of the mean latencies of waves I, III and IV were not significant in initial and post-exposure ABR measurements at both 60 and 80 dB nHL stimulus levels ( P >0.05). Similarly, differences of the mean interwave intervals I-III, I-V and III-V remained insignificant at the initial and postexposure ABR measurements at stimulus levels of both 60 and 80 dB nHL ( P >0.05). Acute exposure to the EMF of mobile phones does not cause perturbations in ABR latencies. However, these negative results should not encourage excessive mobile communication, because minor biological and neurophysiological influences may not be detectable by the current technology.     

Diagnostic implications of stimulus polarity effects on the auditory brainstem response

The purpose of this study was to determine whether clicks presented in rarefaction or condensation modes produce more accurate diagnostic information. Subjects were 20 consecutive patients who were seen at the Mayo Clinic for unilateral acoustic neuromas. The nontumor ear served as a control to minimize intersubject variability in the latencies. A standard audiologic evaluation was followed by an auditory brainstem response (ABR) test for which the stimuli were rarefaction and condensation clicks. Responses were analyzed for the presence of waves I, III, and V; absolute latencies of waves I, III, and V; interpeak intervals I-III, III-V, and I-V; and interaural latency difference for wave V. The results indicated that measures from both polarities were similar in this set of patients and that neither click polarity provided diagnostic advantages over the other. Recommendations are to collect ABRs to both click polarities individually to obtain the full complement of waves on which to base the diagnostic impression.     

Auditory brainstem response in ototoxic deafness

Auditory brainstem response (ABR) had been measured in 56 patients with ototoxic deafness (OD) and 20 healthy children. It was found that the ABR change in the OD group was characterized by the disappearance of waves I, III, V and the prolongation of the latencies. The values of ABR in early diagnosis and evaluation of auditory damage in OD were discussed.     

脑干肿瘤切除术中的听性脑干反应分析

目的 探索脑干肿瘤手术中听性脑干反应（ＡＢＲ）变化规律及其监护作用。方法 对５例脑干肿瘤手术患者,从术前、术中至术后进行了ＡＢＲ的动态观察,对术中监护记录的４００余份ＡＢＲ的潜伏期、振幅和波形分化的资料进行分析和统计学处理。结果 术中牵拉、分离、挤压均可引起ＡＢＲⅠ、Ⅲ和Ｖ波潜伏期延长,振幅降低,波形分化差等改变,其中３例动态变化指标好,呈可逆性变化,均康复出院。另２例术后潜伏期持续延长、波形分化     

Effects of sex on auditory brainstem responses in infancy and early childhood

The effects of sex on I-III, III-V and I-V interwave intervals and I, III, V ABR waves latency values have been studied in 171 normal children born at term, 94 males and 77 females, aged between 2 and 720 days. The obtained data confirm that latency values decrease progressively with age, and show that there is a statistically significant difference in wave III and V latency values and in III-V and I-V intervals between males and females. Moreover, these differences seem to increase with age. The authors also discuss the possible underlying mechanisms and claim that even in infancy, sex-related variability should be taken into account.