Objective To explore the effect of acupuncture at ＂Jing Jiaji＂ （颈夹背） on sudden hearing loss by observing the changes of the threshold of auditory brainstem response （ABR） of deaf guinea pigs. Methods Sixty he...Objective To explore the effect of acupuncture at ＂Jing Jiaji＂ （颈夹背） on sudden hearing loss by observing the changes of the threshold of auditory brainstem response （ABR） of deaf guinea pigs. Methods Sixty healthy guinea pigs were selected, with computer randomization, 20 were randomly divided into a normal control group （group A）, while the rest were randomly and equally divided into a model group （group B） and an acupuncture group （group C） when turned deaf after gentamycin sulfate and furosemide were administered. No treatment was administered for either the group A or the group B, while acupuncture at ＂Jing Jiaji＂ was given for the group C for 30 days. The ABR thresholds of each group were observed and recorded separately after the treatment for 15 days and 30 days. Results The ABR threshold in the group C was lower than that in the group B after the treatment of 15 days （P〈O.05）. After the treatment of 30 days, the ABR threshold in the group C was obviously lower than that in the group B （P〈0.01）, and was obviously lower than that before acupuncture （P〈0.01）. Conclusion Acupuncture at ＂Jing Jiaji＂ has definite effect on improving the hearing of deaf guinea pigs.展开更多
To characterize the patterns of ABR waves in tree shrews, we must understand the hearing sensitivity and auditory function of healthy adult tree shrews. Fifteen tree shrews(30 ears) were stimulated with clicks and ton...To characterize the patterns of ABR waves in tree shrews, we must understand the hearing sensitivity and auditory function of healthy adult tree shrews. Fifteen tree shrews(30 ears) were stimulated with clicks and tone-pips at 11 different frequencies from 1 to 60 kHz. The ABR waves were recorded and analyzed. The ABR consisted of five to seven positive waves in the first 10 ms after a click stimulus, and the average hearing threshold of component III was 27.86 ± 3.78 dB SPL. Wave III was the largest and most clear. The ABR threshold was related to the tone-pip sitmulus by a "U" shaped curve. The sensitive frequency was approximately 8 kHz in tree shrews. The latencies systematically decreased with increasing stimulus frequencies. The ABR amplitudes of wave III increased as the sound pressure level increased. All of these results provide an empirical basis for future studies of hearing diseases in tree shrews.展开更多
The auditory brainstern responses(ABR)and middle latency responses(MLR)were recorded in 24 normal mice with a 7S11A processor,and the normalparameters of ABR and MLR obtained.The results showed that the ABR of mice we...The auditory brainstern responses(ABR)and middle latency responses(MLR)were recorded in 24 normal mice with a 7S11A processor,and the normalparameters of ABR and MLR obtained.The results showed that the ABR of mice werecomposed of 6 waves,waves Ⅰ to Ⅵ.The mean threshold was 35.12±8.03 dB ,whichwas significantly different from the 22.63 dB of ABR found in guinea pigs.Thelatency of ABR waves Ⅰ to Ⅵizn the mice was found to be 1.30±8.03 ms ;2.02±0.24ms ;2.90±0.27 ms ;3.80±0.24 ms ;4.87±0.42 ms and 5.83±0.40 ms respectively.Nosex or strain differences were found.The MLR waveform of the mice were similar tothose of human and the latency was found to be P0 3.94±1.76 ms;P8.38±1.57ms;Na 14.98±2.54 ms;Pa 24.56±3.15 ms rcspectively.It is suggested that mice can beused for hearing research.Since the Na and Pa waves of MLR were unstable under anes-thesia,testing conditions for determining MLR in mice need further study.展开更多
Objective To analyze the characteristics of auditory brainstem response (ABR) in presbycusis patients el-der than 90 years. Methods Fourteen presbycusis patients elder than 90 years (presbycusis group, 91.1.4 ± 1...Objective To analyze the characteristics of auditory brainstem response (ABR) in presbycusis patients el-der than 90 years. Methods Fourteen presbycusis patients elder than 90 years (presbycusis group, 91.1.4 ± 1.3 years, 26 ears) and 9 normal-hearing young adults (control group, 22.7 ± 1.2 years, 18 ears) participated in the study. Alternative click-evoked ABRs were recorded in both groups. The peak latency (PL) of peak I,Ⅲ, and V, and the inter-peak latency (IPI) of I-Ⅲ,Ⅲ-V, and I-V were compared between groups. Results In elder presbycusis patients, the occurrence rate of peak I andⅢwere both 76.9%, and that of peak V was 84.6%. In presbycusis group, the peak latencies of I, Ⅲ, V were significantly longer than that of control group (P<0.001). There was no significant difference between groups in the IPI of peak I-IⅢ (P=0.298, peakⅢ-V (P=0.254) and peak I-V (P=0.364). Conclusions Auditory brainstem responses in presbycusis pa-tients elder than 90 years showed worse wave differentiation.展开更多
Objectives To investigate changes in evoked potentials and structure of the guinea pig cochleae during whole cochlear perfusion with glutamate.Methods CM,CAP,DPOAE,and ABR were recorded as indicators of cochlear funct...Objectives To investigate changes in evoked potentials and structure of the guinea pig cochleae during whole cochlear perfusion with glutamate.Methods CM,CAP,DPOAE,and ABR were recorded as indicators of cochlear functions during whole cochlear perfusion.The morphology of the cochlea was studied via transmission electron microscopy.Results There were no significant changes in DPOAE amplitude before and after glutamate perfusion.CM I/O function remained nonlinear during perfusion.ABR latencies were delayed following glutamate perfusion.The average CAP threshold was elevated 35 dB SPL following glutamate perfusion..The OHCs appeared normal,but the IHCs and afferent dendrites showed cytoplasmic blebs after glutamate perfusion.Conclusions While being a primary amino acid neurotransmitter at the synapses between hair cells and spiral ganglion neurons,excessive glutamate is neurotoxic and can destroy IHCs and spiral ganglion neurons.The technique used in this study can also be used to build an animal model of auditory neuropathy.展开更多
The analysis of the Auditory Brainstem Response (ABR) is of fundamental importance to the investigation of the auditory system behavior, though its interpretation has a subjective nature because of the manual process ...The analysis of the Auditory Brainstem Response (ABR) is of fundamental importance to the investigation of the auditory system behavior, though its interpretation has a subjective nature because of the manual process employed in its study and the clinical experience required for its analysis. When analyzing the ABR, clinicians are often interested in the identification of ABR signal components referred to as Jewett waves. In particular, the detection and study of the time when these waves occur (i.e., the wave latency) is a practical tool for the diagnosis of disorders affecting the auditory system. In this context, the aim of this research is to compare ABR manual/visual analysis provided by different examiners. Methods: The ABR data were collected from 10 normal-hearing subjects (5 men and 5 women, from 20 to 52 years). A total of 160 data samples were analyzed and a pair- wise comparison between four distinct examiners was executed. We carried out a statistical study aiming to identify significant differences between assessments provided by the examiners. For this, we used Linear Regression in conjunction with Bootstrap, as a method for evaluating the relation between the responses given by the examiners. Results: The analysis suggests agreement among examiners however reveals differences between assessments of the variability of the waves. We quantified the magnitude of the obtained wave latency differences and 18% of the investigated waves presented substantial differences (large and moderate) and of these 3.79% were considered not acceptable for the clinical practice. Conclusions: Our results characterize the variability of the manual analysis of ABR data and the necessity of establishing unified standards and protocols for the analysis of these data. These results may also contribute to the validation and development of automatic systems that are employed in the early diagnosis of hearing loss.展开更多
Tinnitus has often been studied using salicylate in animal models as they are capable of inducing tempo-rary hearing loss and tinnitus. Studies have recently observed enhancement of auditory evoked responses of the au...Tinnitus has often been studied using salicylate in animal models as they are capable of inducing tempo-rary hearing loss and tinnitus. Studies have recently observed enhancement of auditory evoked responses of the auditory cortex (AC) post salicylate treatment which is also shown to be related to tinnitus like behavior in rats. The aim of this study was to observe if enhancements of the AC post salicylate treatment are also present at structures in the brainstem. Four male Sprague Dawley rats with AC implanted electrodes were tested for both AC and auditory brainstem response (ABR) recordings pre and post 250 mg/kg intraperitone-al injections of salicylate. The responses were recorded as the peak to trough amplitudes of P1-N1 (AC), ABR wave V, and ABR waveⅡ. AC responses resulted in statistically significant enhancement of ampli-tude at 2 hours post salicylate with 90 dB stimuli tone bursts of 4, 8, 12, and 20 kHz. Wave V of ABR re-sponses at 90 dB resulted in a statistically significant reduction of amplitude 2 hours post salicylate and a mean decrease of amplitude of 31%for 16 kHz. WaveⅡamplitudes at 2 hours post treatment were signifi-cantly reduced for 4, 12, and 20 kHz stimuli at 90 dB SPL. Our results suggest that the enhancement chang-es of the AC related to salicylate induced tinnitus are generated superior to the level of the inferior colliculus and may originate in the AC.展开更多
Vocalizations play a critical role in mate recognition and mate choice in a number of taxa, especially, but not limited to, orthopterans, frogs, and birds. But receivers can only recognize and prefer sounds that they ...Vocalizations play a critical role in mate recognition and mate choice in a number of taxa, especially, but not limited to, orthopterans, frogs, and birds. But receivers can only recognize and prefer sounds that they can hear. Thus a fundamental question linking neurobiology and sexual selection asks-what is the threshold for detecting acoustic sexual displays? In this study, we use 3 methods to assess such thresholds in tdngara frogs: behavioral responses, auditory brainstem responsesz and multi unit electrophysiological recordi ngs from the midbrain.We show that thresholds are lowest for multiunit recordings (ca. 45 dB SPL), and then for behavioral responses (ca. 61 dB SPL), with auditory brainstem responses exhibiting the highest thresholds (ca. 71 dB SPL). We discuss why these estimates differ and why, as with other studies, it is unlikely that they should be the same. Although all of these studies estimate thresholds they are not measuring the same thresholds;behavioral thresholds are based on signal salienee whereas the 2 neural assays estimate physiological thresholds. All 3 estimates, however, make it clear that to have an appreciation for detection and salienee of acoustic signals we must listen to those signals through the ears of the receivers.展开更多
In anurans, calling behaviour is strongly seasonal and circadian. Previous studies have revealed that a uditory sensitivity in frogs exhibits seasonal plasticity, and electroencephalographic signals exhibit highly cor...In anurans, calling behaviour is strongly seasonal and circadian. Previous studies have revealed that a uditory sensitivity in frogs exhibits seasonal plasticity, and electroencephalographic signals exhibit highly correlated circadian patterns;of which, the circadian rhythm remains unknown. In this study,the circadian rhythm and intersexual differences of auditory sensitivity were tested in the Emei music frog(Nidirana daunchina). This was achieved by comparing thresholds and latencies of auditory brainstem responses(ABRs) evoked by tones and clicks stimuli between male and female frogs during the day and at night,respectively. Our results revealed that both auditory thresholds and latencies had no differences between day and night except the la tencies in 3.5–4.0 kHz frequencies. However, the thresholds of tone pip evoked ABRs differed significantly between male and female frogs from 2.5 to 5.0 kHz. This demonstrated that the auditory sensitivity of Emei music frogs exhibits sexual dimorphism at high frequencies, with female frogs exhibiting greater auditory sensitivity than that of male frogs. Simultaneously, the power spectra of male advertisement calls are matched well with the frequency range of auditory sensitivity in male and female frogs,which supports the matched filter hypothesis. Our study enhances the understanding of circadian plasticity and sexual dimorphism of auditory sensitivity in frogs.展开更多
Adult guinea pigs with normal Preyer’s reflexes were used in this experiment and were di-vided into 3 groups according to the intensity of noise and exposure time.Auditory brainstemevoked response was recorded before...Adult guinea pigs with normal Preyer’s reflexes were used in this experiment and were di-vided into 3 groups according to the intensity of noise and exposure time.Auditory brainstemevoked response was recorded before and after exposure to noise.Clicks were presented monaurallyat a rate of high (50Hz) as well as low (10Hz).The superior olive and inferior colliculus were ob-served under an electron microscope after the guinea pigs were exposured to 110dB noise for30min.The average shift of wave Ⅳ amplitude-intensity function curve was more than that ofwave Ⅰ after exposure to intensive noise.The difference value of wave \ latency from low(10Hz) to high (50Hz) stimulus click rate decreased and was negatively correlated with the exposuretime.Ⅰ-Ⅴ,Ⅲ-Ⅴ and Ⅳ-Ⅴ interpeak latencies were shorter after exposure to noise.Themitochondria and neurilemma swelling were found in the superior olive and inferior colliculus afterexposure,Some mechanisms of the changes of auditory center were discussed in this paper.展开更多
Objective:To analyze neurophysiological characteristics in infants and young children with auditory neuropathy(AN) and explore their clinical significance.Methods: Audiological measurements(acoustic immittance, EOAEs,...Objective:To analyze neurophysiological characteristics in infants and young children with auditory neuropathy(AN) and explore their clinical significance.Methods: Audiological measurements(acoustic immittance, EOAEs, ABR, CM, MLR and ERPs) and peripheral neurological tests were conducted and evaluated in 13 infants and young children with AN. Six of them received high-resolution temporal bone CT scans and/or cerebral MRI examinations.Results: All of the children showed type “A” tympanograms with abseatation of stapedial reflexes. EOAEs were normal in 12 of 13 subjects. In one child who had a history of anoxia during the birth,the EOAEs were not elicited. Click-evoked ABRs were absent in 12 of 13 subjects when maximum output of the instrument was reached. The CM potentials were presented bilaterally in all individuals,which were independent of the EOAEs and ABR. Of eight cases tested,all had clear MLR and six showed normal ERPs(P300 and MMN). Peripheral neurological tests and radiological findings were within the normal ranges. Conclusion: The diagnosis of AN in infants and young children should focus on analyzing their neurophysiological characteristics,especially on CM,MLR and ERPs. Combined use of EOAEs, ABR and CM was recommended for hearing screening on newborns with high risk factors.展开更多
基金Supported by Yanbian University on Scientific Development and Application:No.36,yanda kehe zi[2013]
文摘Objective To explore the effect of acupuncture at ＂Jing Jiaji＂ （颈夹背） on sudden hearing loss by observing the changes of the threshold of auditory brainstem response （ABR） of deaf guinea pigs. Methods Sixty healthy guinea pigs were selected, with computer randomization, 20 were randomly divided into a normal control group （group A）, while the rest were randomly and equally divided into a model group （group B） and an acupuncture group （group C） when turned deaf after gentamycin sulfate and furosemide were administered. No treatment was administered for either the group A or the group B, while acupuncture at ＂Jing Jiaji＂ was given for the group C for 30 days. The ABR thresholds of each group were observed and recorded separately after the treatment for 15 days and 30 days. Results The ABR threshold in the group C was lower than that in the group B after the treatment of 15 days （P〈O.05）. After the treatment of 30 days, the ABR threshold in the group C was obviously lower than that in the group B （P〈0.01）, and was obviously lower than that before acupuncture （P〈0.01）. Conclusion Acupuncture at ＂Jing Jiaji＂ has definite effect on improving the hearing of deaf guinea pigs.
基金supported by Natural Science Foundation of China[grant numbers 81760188]Scientific Research Fund of Guangxi Provincial Education Department [grant numbers 2017KY0103 (02601217023C)]
文摘To characterize the patterns of ABR waves in tree shrews, we must understand the hearing sensitivity and auditory function of healthy adult tree shrews. Fifteen tree shrews(30 ears) were stimulated with clicks and tone-pips at 11 different frequencies from 1 to 60 kHz. The ABR waves were recorded and analyzed. The ABR consisted of five to seven positive waves in the first 10 ms after a click stimulus, and the average hearing threshold of component III was 27.86 ± 3.78 dB SPL. Wave III was the largest and most clear. The ABR threshold was related to the tone-pip sitmulus by a "U" shaped curve. The sensitive frequency was approximately 8 kHz in tree shrews. The latencies systematically decreased with increasing stimulus frequencies. The ABR amplitudes of wave III increased as the sound pressure level increased. All of these results provide an empirical basis for future studies of hearing diseases in tree shrews.
文摘The auditory brainstern responses(ABR)and middle latency responses(MLR)were recorded in 24 normal mice with a 7S11A processor,and the normalparameters of ABR and MLR obtained.The results showed that the ABR of mice werecomposed of 6 waves,waves Ⅰ to Ⅵ.The mean threshold was 35.12±8.03 dB ,whichwas significantly different from the 22.63 dB of ABR found in guinea pigs.Thelatency of ABR waves Ⅰ to Ⅵizn the mice was found to be 1.30±8.03 ms ;2.02±0.24ms ;2.90±0.27 ms ;3.80±0.24 ms ;4.87±0.42 ms and 5.83±0.40 ms respectively.Nosex or strain differences were found.The MLR waveform of the mice were similar tothose of human and the latency was found to be P0 3.94±1.76 ms;P8.38±1.57ms;Na 14.98±2.54 ms;Pa 24.56±3.15 ms rcspectively.It is suggested that mice can beused for hearing research.Since the Na and Pa waves of MLR were unstable under anes-thesia,testing conditions for determining MLR in mice need further study.
基金supported by grants from the Science and Technology Innovation Nursery Foundation of PLA General Hospital(12KMM29)the military medical metrology research project(2012-JL1-028)+1 种基金Clinical Research Supporting Foundation of PLA General Hospital(2012FC-TSYS-3056)the Military Medical and Sanitation Research Project(11BJZ33)
文摘Objective To analyze the characteristics of auditory brainstem response (ABR) in presbycusis patients el-der than 90 years. Methods Fourteen presbycusis patients elder than 90 years (presbycusis group, 91.1.4 ± 1.3 years, 26 ears) and 9 normal-hearing young adults (control group, 22.7 ± 1.2 years, 18 ears) participated in the study. Alternative click-evoked ABRs were recorded in both groups. The peak latency (PL) of peak I,Ⅲ, and V, and the inter-peak latency (IPI) of I-Ⅲ,Ⅲ-V, and I-V were compared between groups. Results In elder presbycusis patients, the occurrence rate of peak I andⅢwere both 76.9%, and that of peak V was 84.6%. In presbycusis group, the peak latencies of I, Ⅲ, V were significantly longer than that of control group (P<0.001). There was no significant difference between groups in the IPI of peak I-IⅢ (P=0.298, peakⅢ-V (P=0.254) and peak I-V (P=0.364). Conclusions Auditory brainstem responses in presbycusis pa-tients elder than 90 years showed worse wave differentiation.
文摘Objectives To investigate changes in evoked potentials and structure of the guinea pig cochleae during whole cochlear perfusion with glutamate.Methods CM,CAP,DPOAE,and ABR were recorded as indicators of cochlear functions during whole cochlear perfusion.The morphology of the cochlea was studied via transmission electron microscopy.Results There were no significant changes in DPOAE amplitude before and after glutamate perfusion.CM I/O function remained nonlinear during perfusion.ABR latencies were delayed following glutamate perfusion.The average CAP threshold was elevated 35 dB SPL following glutamate perfusion..The OHCs appeared normal,but the IHCs and afferent dendrites showed cytoplasmic blebs after glutamate perfusion.Conclusions While being a primary amino acid neurotransmitter at the synapses between hair cells and spiral ganglion neurons,excessive glutamate is neurotoxic and can destroy IHCs and spiral ganglion neurons.The technique used in this study can also be used to build an animal model of auditory neuropathy.
文摘The analysis of the Auditory Brainstem Response (ABR) is of fundamental importance to the investigation of the auditory system behavior, though its interpretation has a subjective nature because of the manual process employed in its study and the clinical experience required for its analysis. When analyzing the ABR, clinicians are often interested in the identification of ABR signal components referred to as Jewett waves. In particular, the detection and study of the time when these waves occur (i.e., the wave latency) is a practical tool for the diagnosis of disorders affecting the auditory system. In this context, the aim of this research is to compare ABR manual/visual analysis provided by different examiners. Methods: The ABR data were collected from 10 normal-hearing subjects (5 men and 5 women, from 20 to 52 years). A total of 160 data samples were analyzed and a pair- wise comparison between four distinct examiners was executed. We carried out a statistical study aiming to identify significant differences between assessments provided by the examiners. For this, we used Linear Regression in conjunction with Bootstrap, as a method for evaluating the relation between the responses given by the examiners. Results: The analysis suggests agreement among examiners however reveals differences between assessments of the variability of the waves. We quantified the magnitude of the obtained wave latency differences and 18% of the investigated waves presented substantial differences (large and moderate) and of these 3.79% were considered not acceptable for the clinical practice. Conclusions: Our results characterize the variability of the manual analysis of ABR data and the necessity of establishing unified standards and protocols for the analysis of these data. These results may also contribute to the validation and development of automatic systems that are employed in the early diagnosis of hearing loss.
文摘Tinnitus has often been studied using salicylate in animal models as they are capable of inducing tempo-rary hearing loss and tinnitus. Studies have recently observed enhancement of auditory evoked responses of the auditory cortex (AC) post salicylate treatment which is also shown to be related to tinnitus like behavior in rats. The aim of this study was to observe if enhancements of the AC post salicylate treatment are also present at structures in the brainstem. Four male Sprague Dawley rats with AC implanted electrodes were tested for both AC and auditory brainstem response (ABR) recordings pre and post 250 mg/kg intraperitone-al injections of salicylate. The responses were recorded as the peak to trough amplitudes of P1-N1 (AC), ABR wave V, and ABR waveⅡ. AC responses resulted in statistically significant enhancement of ampli-tude at 2 hours post salicylate with 90 dB stimuli tone bursts of 4, 8, 12, and 20 kHz. Wave V of ABR re-sponses at 90 dB resulted in a statistically significant reduction of amplitude 2 hours post salicylate and a mean decrease of amplitude of 31%for 16 kHz. WaveⅡamplitudes at 2 hours post treatment were signifi-cantly reduced for 4, 12, and 20 kHz stimuli at 90 dB SPL. Our results suggest that the enhancement chang-es of the AC related to salicylate induced tinnitus are generated superior to the level of the inferior colliculus and may originate in the AC.
文摘Vocalizations play a critical role in mate recognition and mate choice in a number of taxa, especially, but not limited to, orthopterans, frogs, and birds. But receivers can only recognize and prefer sounds that they can hear. Thus a fundamental question linking neurobiology and sexual selection asks-what is the threshold for detecting acoustic sexual displays? In this study, we use 3 methods to assess such thresholds in tdngara frogs: behavioral responses, auditory brainstem responsesz and multi unit electrophysiological recordi ngs from the midbrain.We show that thresholds are lowest for multiunit recordings (ca. 45 dB SPL), and then for behavioral responses (ca. 61 dB SPL), with auditory brainstem responses exhibiting the highest thresholds (ca. 71 dB SPL). We discuss why these estimates differ and why, as with other studies, it is unlikely that they should be the same. Although all of these studies estimate thresholds they are not measuring the same thresholds;behavioral thresholds are based on signal salienee whereas the 2 neural assays estimate physiological thresholds. All 3 estimates, however, make it clear that to have an appreciation for detection and salienee of acoustic signals we must listen to those signals through the ears of the receivers.
基金supported by National Natural Science Foundation of China (31772464)Youth Innovation Promotion Association CAS (2012274)。
文摘In anurans, calling behaviour is strongly seasonal and circadian. Previous studies have revealed that a uditory sensitivity in frogs exhibits seasonal plasticity, and electroencephalographic signals exhibit highly correlated circadian patterns;of which, the circadian rhythm remains unknown. In this study,the circadian rhythm and intersexual differences of auditory sensitivity were tested in the Emei music frog(Nidirana daunchina). This was achieved by comparing thresholds and latencies of auditory brainstem responses(ABRs) evoked by tones and clicks stimuli between male and female frogs during the day and at night,respectively. Our results revealed that both auditory thresholds and latencies had no differences between day and night except the la tencies in 3.5–4.0 kHz frequencies. However, the thresholds of tone pip evoked ABRs differed significantly between male and female frogs from 2.5 to 5.0 kHz. This demonstrated that the auditory sensitivity of Emei music frogs exhibits sexual dimorphism at high frequencies, with female frogs exhibiting greater auditory sensitivity than that of male frogs. Simultaneously, the power spectra of male advertisement calls are matched well with the frequency range of auditory sensitivity in male and female frogs,which supports the matched filter hypothesis. Our study enhances the understanding of circadian plasticity and sexual dimorphism of auditory sensitivity in frogs.
文摘Adult guinea pigs with normal Preyer’s reflexes were used in this experiment and were di-vided into 3 groups according to the intensity of noise and exposure time.Auditory brainstemevoked response was recorded before and after exposure to noise.Clicks were presented monaurallyat a rate of high (50Hz) as well as low (10Hz).The superior olive and inferior colliculus were ob-served under an electron microscope after the guinea pigs were exposured to 110dB noise for30min.The average shift of wave Ⅳ amplitude-intensity function curve was more than that ofwave Ⅰ after exposure to intensive noise.The difference value of wave \ latency from low(10Hz) to high (50Hz) stimulus click rate decreased and was negatively correlated with the exposuretime.Ⅰ-Ⅴ,Ⅲ-Ⅴ and Ⅳ-Ⅴ interpeak latencies were shorter after exposure to noise.Themitochondria and neurilemma swelling were found in the superior olive and inferior colliculus afterexposure,Some mechanisms of the changes of auditory center were discussed in this paper.
文摘Objective:To analyze neurophysiological characteristics in infants and young children with auditory neuropathy(AN) and explore their clinical significance.Methods: Audiological measurements(acoustic immittance, EOAEs, ABR, CM, MLR and ERPs) and peripheral neurological tests were conducted and evaluated in 13 infants and young children with AN. Six of them received high-resolution temporal bone CT scans and/or cerebral MRI examinations.Results: All of the children showed type “A” tympanograms with abseatation of stapedial reflexes. EOAEs were normal in 12 of 13 subjects. In one child who had a history of anoxia during the birth,the EOAEs were not elicited. Click-evoked ABRs were absent in 12 of 13 subjects when maximum output of the instrument was reached. The CM potentials were presented bilaterally in all individuals,which were independent of the EOAEs and ABR. Of eight cases tested,all had clear MLR and six showed normal ERPs(P300 and MMN). Peripheral neurological tests and radiological findings were within the normal ranges. Conclusion: The diagnosis of AN in infants and young children should focus on analyzing their neurophysiological characteristics,especially on CM,MLR and ERPs. Combined use of EOAEs, ABR and CM was recommended for hearing screening on newborns with high risk factors.
