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.     

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.     

Auditory brainstem responses to tonal stimuli in young and aging rats

The auditory brain stem response (ABR) was studied in young adult and aged rats using 3,8 and 40 kHz tone pips. The expected inverse relationship between frequency and latency was observed in the younger group for waves I, II and III, while the response to the highest frequency stimulus had the longest latency at wave V. Absolute latencies for waves I through V each showed age-related increments with more pronounced changes occurring to 3 and 40 kHz stimuli than to the frequency of maximum sensitivity (8 kHz). Threshold increases with age for the highest frequency approximately doubled those for the lower frequencies. Examination of interpeak intervals (IPI) I-III, III-V and I-V revealed aging effects. The largest IPI I-V increment occurred to 3 kHz stimulation which reflects changes at both I-III and III-V sub-intervals. These results demonstrate electrophysiological correlates of aging due to transformations in the peripheral auditory system coupled with alterations in brainstem auditory pathways.     

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.     

ABR latency in infants: properties and applications of various measures

ABR latency ratios have been proposed as useful clinical tools in the assessment of infants at risk for auditory or neurologic deficits. These parameters, together with classical absolute and interwave latency measures, were examined in 131 infants with normal ABR thresholds at 48-64 weeks post-conceptional age, and with no conventional risk factor for hearing impairment or neurological abnormality. Latency of wave I is unaffected by age or gender, but that of waves III and V decreases linearly with age and is smaller in females. These effects must be accounted for in clinical evaluation. However, latency ratios V/I, V/III and III/I show no significant age or gender effects. Wave I latency and the V/I latency ratio both permitted very good discrimination between normal infants and those with presumed conductive hearing losses, but the effects of sensorineural impairment have yet to be determined. On a priori grounds it seems improbable that latency ratios will outperform classical ABR parameters, at least for the goals and age range considered in this study.     

The normative basis for click and frequency-specific BERA in high-risk infants

The use of brainstem electric response audiometry (BERA) for early detection of hearing loss is predicated upon large-sample normative data. Auditory brainstem response (ABR) thresholds for click and notch-masked tonepip stimuli were examined in 230 normal infants with no risk factors for hearing loss, tested under audiometrically ideal conditions at between 48 and 56 weeks post-conception. The ABR threshold distributions for clicks and tonepips differed considerably. Almost all infants had click thresholds consistent with normal hearing on adult criteria, whereas many appeared to have hearing loss at 500 Hz. ABR latencies for 70 dBnHL clicks were more variable than expected, even in infants with click thresholds of 30 dB or better. In males, wave V latency was about 0.2 ms larger than in females, but there was no such difference for wave I. For both sexes, there was a linear decrease in wave V latency with age at approximately 0.1 ms per month, but wave I latency was constant.     

Auditory brainstem responses as a clinical evaluation tool in children after perinatal encephalopathy

Auditory brainstem responses (ABR) reveals the neurophysiological status of the neural axis. In this study we compared the ABR of healthy children, under 1-year-old, with children who suffered from perinatal encephalopathy (PE). OBJECTIVE: The purpose of this study was to characterize the ABR differences between children with PE and healthy children in order to identify groups with specific neurophysiological profiles, associated with their neurological condition. METHODS: Thirty-six children with perinatal encephalopathy (PE) and 36 healthy children, ages 1-12 months, were studied. The variables considered were: latencies of waves I, II, N1, III, V, and N2; interpeak latency interval (IPL) of waves I-III, III-V, and I-V; as well as amplitudes of waves I, III, and V. The results were analyzed using ANOVA, as well as Ji(2), and Ward's cluster analysis. RESULTS: The absolute latencies of the ABR showed an inverse correlation with the children's age. Latencies of waves I, II, N1, V, and N2, IPL III-V, and amplitude of waves III and V show significant differences (p<0.05) between healthy and PE children. Children with PE showed greater absolute latencies and larger wave amplitudes than the control group. Ward's cluster analysis, used to define the groups with similar functional characteristics, revealed three groups: fast, intermediate, and slow-responders, depending on their wave latencies and IPL wave amplitudes. These groups were gender- (p<0.03), age- (p<0.0001), and neurological damage- (p<0.01) related. CONCLUSIONS: Our data clearly show that the ABR obtained from PE children differ from ABR obtained from healthy children. PE infants showed larger wave latencies, intervals amplitudes than the control group. Three functional profiles resulted from the groups established using the Ward's method, and these indicate their neurological functional condition.     

Influence of age, sex, and hearing loss on auditory brain stem response (ABR) latencies

In a previous paper, the hypothesis was established that the shorter auditory brain stem response (ABR) latencies in females, in comparison with males, can be explained solely by the age dependence of the latencies, which is more pronounced in males than in females. According to this concept, ABR latencies in male and female babies are identical but diverge increasingly with increasing age. A multiple regression analysis on considerably enlarged male and female groups has now confirmed the hypothesis as to the differing age dependence in males and females. But the results also show that the male/female ABR latency differences cannot be explained solely by these differences in age dependence. An additional factor has to be taken into account, for which the male/female difference in auditory pathway length is a plausible explanation.     

Variables affecting the auditory brainstem response: audiogram, age, gender and head size

Correlations between the ABR (auditory brainstem response) and the variables of hearing loss, gender, head size and age were determined in simple and multiple regression analyses in 334 ears. The stepwise multiple regression analyses for waves I, III and V of the ABR was used to determine the relative importance of the variables. Regression equations were calculated for the latency of each wave. Wave I latency for all subjects is best predicted by hearing threshold at 8 kHz, gender and age, in that order. Wave III latency depends upon hearing threshold at 4 kHz, age and gender. The latency of wave V is best predicted by gender, age and head diameter with threshold at 4 kHz being of minor importance. The I-V interval depends upon head diameter and threshold at 8 and 4 kHz with age of minor importance. Hearing loss at 8 kHz would shorten the I-V interval, while a loss at 4 kHz would be expected to lengthen the interval. Correlations of these variables with the amplitude of I, III and V are also described. Latency and amplitude are correlated with different subject variables suggesting differences in their generation.     

Statistical dependence among the wave latencies of the auditory brain stem response

If the interpeak intervals in the auditory brain stem response (ABR) are assumed to be statistically independent variables that represent the neural transmission time between loci, then the absolute latency of an ABR wave is the sum of the transmission times between successive loci. Consequently, the correlations between the absolute latencies of the ABR waves would be part-whole correlations whose expected values are appreciably different from r = 0. We derived the expected values of the correlations between the latencies of the ABR waves on the assumption that their latencies are the sum of independent elements (transmission times) and found them to be 0.707, 0.577, and 0.816 for I.III, I.V, and III.V, respectively. In addition, the expected values of the correlations between the latencies of the ABR waves assuming that the absolute wave latencies themselves are independent variables (e.g., rI.III = 0) were derived. Several of the correlations among interpeak and between the interpeak and absolute latencies were demonstrated to be appreciably different from r = 0. It would appear that it is more reasonable to assume that the elements (transmission times) rather than the component latencies are the variables of choice for statistical analysis of ABR data.     

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.     

Development of low-frequency tone burst versus the click auditory brainstem response

Often ABR threshold testing employs clicks to assess high-frequency hearing, and low-frequency tone bursts to assess low-frequency sensitivity. While a maturation effect has been shown for click stimuli, similar data are lacking for low-frequency toneburst stimuli. Thus, 305 infants ranging in conceptional age (CA) from 33 weeks to 74 weeks were tested. Absolute latencies were measured for wave V at 55, 35, and 25 dB nHL in response to a click and for wave V500 in response to a 500 Hz tone burst. Major wave latency in response to 500 Hz tone bursts decreases with age and do not stabilize by 70 weeks CA. Likewise, waves III and V latencies in response to clicks decrease with age, as has been reported by others, and do not stabilize by 70 weeks CA. Wave I latency produced by clicks did not decrease with age, being mature by 33 weeks CA.     

Effects of sex, age and hearing asymmetry on the interaural differences of auditory brainstem responses

Healthy patients with asymmetric sensorineural hearing loss who had received examination of auditory brainstem responses (ABR) were gathered for retrospective analysis. The effects of sex, age and hearing asymmetry on the interaural differences of ipsilateral ABR were determined by multivariant linear regression. Our results showed that the interaural differences of ABR wave III and wave V latencies were significantly affected by hearing asymmetry but not by sex or age. However, in female subjects younger than 50 years, differences of III-V intervals could be negatively correlated with hearing asymmetry. We suggest that plasticity in the auditory brainstem in younger females might account for asymmetrical peripheral hearing in this group.     

Could Tailored Chirp Stimuli Benefit Measurement of the Supra-threshold Auditory Brainstem Wave-I Response?

Auditory brainstem responses (ABRs) to broadband clicks are strongly affected by dyssynchrony, or “latency dispersion”, of their frequency-specific cochlear contributions. Optimized chirp stimuli, designed to compensate for cochlear dispersion, can afford substantial increase in broadband ABR amplitudes, particularly for the prominent wave-V deflection. Reports on the smaller wave I, however, which may be useful for measuring cochlear synaptopathy, have been mixed. This study aimed to test previous claims that ABR latency dispersion differs between waves I and V, and between males and females, and thus that using wave- and/or sex-tailored chirps may provide more reliable wave-I benefit. Using the derived-band technique, we measured responses from frequency-restricted (one-octave-wide) cochlear regions to energy-matched click and chirp stimuli. The derived-band responses’ latencies were used to assess any wave- and/or sex-related dispersion differences across bands, and their amplitudes, to evaluate any within-band dispersion differences. Our results suggest that sex-related dispersion difference within the lowest-frequency cochlear regions (< 1 kHz), where dispersion is generally greatest, may be a predominant driver of the often-reported sex difference in broadband ABR amplitude. At the same time, they showed no systematic dispersion difference between waves I and V. Instead, they suggest that reduced chirp benefit on wave I may arise as a result of chirp-induced desynchronization of on- and off-frequency responses generated at the same cochlear places, and resultant reduction in response contributions from higher-frequency cochlear regions, to which wave I is thought to be particularly sensitive.

     

Auditory brainstem responses from children three months to three years of age: normal patterns of response. II

Auditory brainstem responses (ABR) were measured in 535 children from 3 months to 3 years of age. The latencies reported in this paper should be unaffected by peripheral hearing loss because each child had bilateral wave V responses at 20 dB HLn. Wave V latencies decreased as age increased, at least to 18 months of age, while little or no change was noted in wave I latencies over the same age range. Thus, interpeak latency differences followed the same developmental time course as wave V. The shapes of wave V latency-level functions were comparable across age groups. These results suggest that changes in wave V latency with age are due to central (neural) factors and that age-appropriate norms should be used in evaluations of ABR latencies in children. Interaural differences in absolute wave V latencies and interpeak latency differences were similar to those observed in infants and adults, indicating that response symmetry is independent of age. Statistical analyses suggested that the distributions of absolute and relative latency measurements are normal, making it possible to describe norms in terms of means and standard deviations. A simple model is described that accounts accurately for changes in mean wave V latencies as function of age from preterm through the first three years of life.     

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.     

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 stimulus repetition rate and frequency on the auditory brainstem response in normal cochlear-impaired, and VIII nerve/brainstem-impaired subjects

The effects of signal repetition rate and frequency on the auditory brainstem responses of normal listeners, of persons with cochlear lesions, and of persons with VIII nerve/brainstem lesions were evaluated. The normal group exhibited more waves I and II than did the cochlear and VIII/brainstem groups. The normal and cochlear groups exhibited more waves III and V than did the VIII nerve/brainstem group. The latency of wave I was not different among groups, whereas wave V was significantly later in the VIII nerve/brainstem group than in the other groups. Waves I, III, and V were later for 50/s than for 10/s. Waves I and III displayed shorter latencies for 4000 Hz than for 2000 Hz, whereas wave V displayed similar latencies for the two stimuli. In conclusion, cochlear pathology (less than or equal to 65 dB HL) does not prolong the latencies of waves I and V. A dual mechanism is discussed to explain the rate-dependent latency shift of wave V.     

Electrophysiological examinations (ABR and DPOAE) of hearing organ in hemodialysed patients suffering from chronic renal failure

Deterioration of function of hearing organ is one of the most important clinical problem in uremic patients with chronic renal failure. The present study aimed to assess the function of hearing organ using the brainstem auditory evoked responses (ABR), impedance audiometry and distortion product otoacoustic emission cochlear function (DPOAE) in 31 haemodialysed patients with chronic renal failure (16 females and 15 males, mean age 43.0 years). The control group consisted of 15 healthy subjects. The latency of the waves I, III, V and I-V interpeak in evoked response audiometry were significantly longer in the patients with CRF (chronic renal failure) compared to the control group. Measurement of DPOAE showed decrease of DPOAE level in patients suffering from CRF. A influence of single hemodialysis and treatment of hemodialysis by 6 months on ABR latencies and DPOAE values were not observed.     

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.