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OBJECTIVES@#To explore the relationship between the frequency characteristics and response threshold of auditory steady-state response (ASSR), auditory brainstem response (ABR) and 40 Hz auditory event related potential (40 Hz AERP), and their application values in forensic medicine.@*METHODS@#Thirty volunteers with normal hearing (60 ears) were selected to perform pure tone audiometry (PTA) threshold and ASSR, ABR and 40 Hz AERP response threshold tests in the standard sound insulation shielding room, and the results were statistically analyzed by SPSS 22.0 software.@*RESULTS@#At 0.5 kHz and 1.0 kHz frequencies, the correlation between 40 Hz AERP response threshold and PTA threshold was good, which was better than that of ASSR and ABR response threshold. At 2.0 kHz and 4.0 kHz frequencies, the correlation between ASSR and ABR response thresholds and PTA threshold was good, which was better than that of 40 Hz AERP response threshold.@*CONCLUSIONS@#To evaluate the hearing at 0.5 kHz and 1.0 kHz frequencies, it is recommended to use 40 Hz AERP and ASSR to comprehensively assess the PTA threshold of the subjects. To evaluate the hearing at 2.0 kHz and 4.0 kHz frequencies, ABR and ASSR are recommended to assess the PTA threshold of subjects comprehensively. The combination of ASSR, ABR and 40 Hz AERP can improve the accuracy of hearing function evaluation.
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Humans , Acoustic Stimulation/methods , Audiometry, Evoked Response , Audiometry, Pure-Tone , Auditory Threshold/physiology , Evoked Potentials, Auditory, Brain Stem/physiology , Forensic Medicine , Hearing/physiologyABSTRACT
Objective To study the possible mechanism of hearing impairment after noise exposure .Methods Adult SD rats (n=14) were monaurally exposed to a loud noise (16 kHz ,one octave band pass (116 dB SPL)) for 1-hour ,or left as non-exposed controls (n=8) .The ABR was measured before and on the 7th day following unilateral noise exposure .All the Animals were euthanased at 7th day following acoustic trauma .We used Western blots to quantify protein levels of PV ,CR and CB in the inferior colliculus .Results The auditory thresholds in 8 , 12 ,16 ,20 ,24 ,and 32 kHz of all the ears exposed to noise showed a significant increase (P<0 .001) .Compared to the sham -exposed controls ,noise-exposed animals had significantly higher levels of PV and CR and lower levels of CB in both the ipsilateral and contralateral IC than controls (P<0 .05) .Respectively ,all the noise-exposed ani-mals had higher levels of PV and CR in the ipsilateral IC than ipsilateral side (P<0 .05) .Conclusion These studies display a significant threshold shift and changes on the expressions of PV ,CR and CB in IC following acoustic trau-ma ,which may be related to noise deafness ,tinnitus and other series of auditory dysfunction .
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Objective To understand the characteristics of the hearing loss in patients with small acoustic neuroma .Methods A retrospective analysis was used to analyze the results of pure tone audiometry (PTA) and au-ditory brainstem response (ABR) in 35 patients (35 ears) diagnosed with small acoustic neuroma .The types of au-diometric curves ,degrees and frequencies of hearing loss and latent periods of ABR were analyzed .Results Moder-ate deafness was the most common type in this study ,with a total of 13 ears (37 .14％ ,13/35) .In addition ,8 ears were profound deafness (22 .86％ ,8/35) ,7 ears of binaural severe deafness (20 .00％ ,7/35) ,6 ears of mild deafness (17 .14％ ,6/35) ,and 1 normal ear (2 .86％ .1/35) ,respectively .The types of audiometric curves were mainly U -shaped and sloping .15 audiometric curves were U -shaped (42 .86％ ,15/35) ,15 sloping (42 .86％ ,15/35) ,3 flat (8 .57％ ,3/35) ,and 1 tent-shaped (2 .86％ .1/35％ ) .The main frequencies of hearing loss were 1 kHz ,2 kHz ,4 kHz ,and 8 kHz .The mean thresholds had statistically significant differences (P<0 .05) compared with the other frequencies by S -N -K test .ABR was abnormal in 32 ears(91 .43％ ,32/35) .20 of the ears'I - V waves were prolonged or the inter-aural latency difference of V wave was>0 .4 ms .Five ears failed to show any ABR wave , but their 4 kHz pure tone threshold was < 80 dB HL .25 (71 .43％ ,25/35)ears'ABR results indicated a retroco-chlear nature of ear disease .Conclusion Moderate deafness is the most common type of hearing loss in small acous-tic neuroma patients ,but only 71 .43％ of the patients'ABR indicate a retrocochlear disease ,so an analysis of PTA together with ABR will help to diagnose .
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Objective To investigate the expression of transmembrane protein 16A (TMEM16A)in the cochlea of guinea pigs and its relationship with the age-related hearing loss.Methods We used auditory brainstem response (ABR)to explore the changes of hearing in guinea pigs of different age (groups of 2 w,3 m,1 y,and D-galactose).The distribution and expression of TMEM16A in the cochlea were detected by immunofluorescence and Western blot.Results ABR threshold was gradually increased,with significant difference between D-gal and the other three groups (P <0.01).TMEM16A was expressed in the cochlear striae vascularis at different ages,and the expression increased with age before 1 y (P <0.05). However, its level was increased in D-gal group and significantly differed from that in 3 m and 1 y groups (P < 0.05 ).Conclusion The change in TMEM16A expression in the cochlear striae vascularis of guinea pigs may be related to age-related hearing loss.
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Objective To investigate the expression of transmembrane protein 16A (TMEM16A)in the cochlea of guinea pigs and its relationship with the age-related hearing loss.Methods We used auditory brainstem response (ABR)to explore the changes of hearing in guinea pigs of different age (groups of 2 w,3 m,1 y,and D-galactose).The distribution and expression of TMEM16A in the cochlea were detected by immunofluorescence and Western blot.Results ABR threshold was gradually increased,with significant difference between D-gal and the other three groups (P <0.01).TMEM16A was expressed in the cochlear striae vascularis at different ages,and the expression increased with age before 1 y (P <0.05). However, its level was increased in D-gal group and significantly differed from that in 3 m and 1 y groups (P < 0.05 ).Conclusion The change in TMEM16A expression in the cochlear striae vascularis of guinea pigs may be related to age-related hearing loss.
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Objective To investigate the synergistic effects of simulated microgravity and noise on the audito‐ry functions and corti organs in rats .Methods A total of 48 healthy rats were randomly divided into 4 groups (n=12):control group (Group A) ,microgravity only group (Group B) ,noise only group (Group C) and microgravity+noise group (Group D) .The microgravity environment was simulated by suspending the posterior limb using Morey-Holton method .The noise exposure was the simulation of the noise environment in spaceship including steady -state noise (72 ± 2) dB SPL and impulse noise up to 160 dB SPL .The control group was kept in normal conditions without any exposure .Auditory brainstem responses (ABRs) ,HE stainings ,immunofluorescence stainings and scanning electron microscopes (SEMs) were tested after 1week and 2 weeks exposure respectively (n=6) .Results The average of ABR threshold shifts of 2 weeks exposure were higher than those of 1 week in each group .Group D showed the highest ABRs (P<0 .01) .The HE stainings showed different degrees of injury in corti organs in all experimental groups ;which Group D being the most serious ,followed by Group C .The results of immunefluorescence in hair cells showed that swelling necrosis was the main damage of cochlear hair cell after 1 week's exposure .The swelling rate of Group D was the highest ,followed by Group C .Nucleus missing in hair cells was observed after 2 weeks'exposure . Group D had the highest missing rate and the main missing of Group B happened in the inner hair cells .SEM showed that the most serious damage of stereociliums in Group D ,followed by Group C ,then Group B .Conclusion The synergistic effects of simulated microgravity and noise lead to significant damage of the auditory function and cochlea Corti organs in rat .
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Objective To establish the mice model of AHL, to investigate the relationship between AHL and the cytoactive factors of the cochlear hair cells in C57BL/6J mice, and to classify the presbycusis models of the C57BL/6J mice. Methods C57BL/6J mice were divided into 6 experimental groups by age (A: 3 months old(m), B: 8 m, C: 9 m, D: 10 m, F: 17 m, G: 18 m) . The auditory functions mice were measured by auditory brainstem response (ABR) with the stimulus click and toneburst at 6 kHz and 8 kHz. 3 months later, Groups C , G, E and H were tested again for ABR. After ABR testing, the cytoactive of the hair cells was detected by succinate dehydrogenase staining and surface preparation technique(two mice from each group except groups C and G). Results The ABR thresholds elevated with age, and the marked change of the cochlea was the degeneration of the cytoactive of the cochlear hair cells, especially those of the outer hair cells. In the beginning, the basement of the basal membrane suffered from the mitochondrion degeneration in the outer hair cells, then it spread to the top region. Subsequently, the inner hair cells were involved. Conclusion C57BL/6J mouse was a typical animal model for the AHL,and the main change of the cochlea was the degeneration of the hair cells, especially the outer hair cells. Thus, C57BL/6J mice can be used as a suitable animal model for the study of presbycusis.
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BACKGROUND: In large clinical series, noise induced hearing loss (NIHL) following middle ear surgery has been demonstrated in 1.2% to 4.5% of patients and it is associated with a lower incidence than expected. The aim of the present work was to analyze the effect of halothane anesthesia on NIHL and hair cell morphological change. METHODS: We used 40 BALB/c mice with normal Preyer's reflex to investigate the effect of halothane on the NIHL. Control (n = 20) and halothane group (n = 20, respectively) were exposed to 120 dB SPL (sound pressure level), broad band white noise 3 hours daily for 3 consecutive days. The halothane group was anesthetized with halothane while exposed to noise. Hearing thresholds were determined with the auditory brainstem response (ABR). On day 7 post-noise, mice were sacrificed and the cochlea were collected for the histological study. RESULTS: ABR thresholds in the halothane group were less elevated after noise exposure than in the control group and then gradually recovered. In control group, the damage to the outer hair cell and supporting cell was noticeable, but not in halothane group. The expression of Bcl-2 protein was detected in halothane group, the expression of Bax protein was seen in control group. As a result in TUNEL stain, the result is positive in the control group but negative in the halothane group. CONCLUSIONS: The occurrence of NIHL decreased and the tissue damage was suppressed while anesthetized by halothane. And the noise-induced cell death of hair cell was also suppressed during anesthesia.
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Animals , Humans , Mice , Anesthesia , Apoptosis , bcl-2-Associated X Protein , Cell Death , Cochlea , Ear, Middle , Evoked Potentials, Auditory, Brain Stem , Hair , Halothane , Hearing Loss , Hearing , In Situ Nick-End Labeling , Incidence , Noise , ReflexABSTRACT
BACKGROUND: It is well known that the loud noise exposure can lead to noise-induced hearing loss (NIHL). Drilling during mastoid surgery may result in NIHL. The noise level produced by drilling of the mastoid bone can exceed 125 dB HL (hearing level); therefore, mastoid surgery itself is associated with a lower incidence of NIHL than expected. The aim of this study was to analyze the effects of isoflurane on NIHL and hair cell morphological changes. METHODS: BALB/c mice were divided into 2 groups; a control group (n = 20) and an isoflurane group (n = 20). The mice of both groups were exposed to 120 dB SPL (sound pressure level) broadband white noise for 3 hours per day, for 3 consecutive days. The mice in the isoflurane group were anesthetized with isoflurane while exposed to the noise. The auditory brainstem response (ABR) thresholds were determined 1 day before and after the noise-exposure and then again after 7 days. Both cochlea were removed and stained using fluorescent isothiocyanate (FITC) phalloidin. RESULTS: 1 day prior to noise-exposure, the ABR thresholds were those of a normal hearing level in both the control and isoflurane groups. In the control group, the mean hearing threshold was 78.0+/-2.6 dB HL after 1 day of noise-exposure and 81.5+/-3.4 dB HL after 1 week; in the isoflurane group, the mean hearing threshold was 49+/-11.7 dB HL after 1 day and 30.5+/-9.3 dB HL after 1 week. The hearing thresholds after noise exposure in the control were significantly higher than those in the isoflurane group (P<0.05). CONCLUSIONS: The occurrence of NIHL decreased and the hair cell damage suppressed in the mice exposed to intense noise while anesthetized by isoflurane.
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Animals , Mice , Cochlea , Evoked Potentials, Auditory, Brain Stem , Hair , Hearing , Hearing Loss, Noise-Induced , Incidence , Isoflurane , Mastoid , Noise , PhalloidineABSTRACT
PURPOSE: The study aimed to evaluate the efficacy of auditory brainstem response(ABR) as a screening tool in children with speech and language disorders. METHODS: Between January 1, 1999 and December 31, 2001, 139 patients with chief complaints of speech and language delay were recruited from the pediatric neurology clinic, Kyungpook National University Hospital, Daegu, Korea. They had ABR on entry and the clinical data were then analyzed. RESULTS: Fifteen out of 139 cases(10.8%) showed abnormal findings; seven had pervasive developmental disorders, four had developmental language disorders, and four were noted to have other conditions. Among them, seven cases were noted to have conductive hearing loss and eight had sensoryneuronal hearing loss. We also evaluated the normal values in children at the ages of 18 months to seven years. The mean latency of wave I and V were 1.40+/-0.13 and 5.57+/-0.26 respectively. Interpeak latency of I-V was 4.18+/-0.24. CONCLUSION: Based on these findings, ABR has proved to be a highly sensitive and specific index of hearing impairment. It should be used as a screening tool in children with speech and language disorders.
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Child , Humans , Brain Stem , Hearing Loss , Hearing Loss, Conductive , Korea , Language Development Disorders , Language Disorders , Mass Screening , Neurology , Reference ValuesABSTRACT
Objective To evaluate and compare the results of air-conduct and bone-conduct auditory brainstem response(ABR)for the purpose of clinical application of the bone-conduct ABR.Methods A group of normal hearing young adults(61 ears)were measured with click stimulation air-conduct ABR and bone-conduct ABR in a soundproof chamber.Results The waveforms of bone-conduct ABR were almost the same as those of air-conduct ones with the threshold of 26.08?7.71 dB(nHL),but with a lower rate of wave derivation.There were no significant differences between male and female for both air-conduct and bone-conduct ABR testing.The threshold for bone-conduct ABR was higher than that of air-conduct one with a very high positive correlation(r=0.7740)and there were significant differences (P0.05) for the wave intervals.Conclusion The limitation of the bone-conduct ABR application and the differences from air-conduct should be considered when it was used clinically.
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Objective To explore the characteristics of auditory brainstem response(ABR) in children with otitis media with effusion(OME) before and after myringotomy with grommet insertion and the significance of ABR in diagnosing OME.Methods ABR were recorded in 50 cases(100 ears) before receiving myringotomy with grommet insertion for OME,30 cases(60 ears) underwent ABR monitoring after surgery again.For comparison,50 age-matched healthy children(100 ears) were also tested with ABR.Furthermore,30 cases were divided into two groups according to the viscidity of tympanic cavity secretion and the response threshold of wave Ⅴ were compared between the two groups.Results The response threshold of wave Ⅴand the peak latency of wave Ⅰwere normal in 13 percent of 50 cases(100 ears) before surgery.The rate of missed diagnosis was 13%.Among 50 cases,41% had normal response threshold for wave Ⅴ,52% had slight abnormal responses of thresholds of wave Ⅴ and 7% had medium response threshold of wave Ⅴ.The peak latency of wavs Ⅰwas normal in 19% OME children,but it prolonged in 72% OME children and absent in 9% OME children.The prolonged peak latencies(waves Ⅰ,Ⅲ andⅤ) and eleveted response thresholds of wave Ⅴ and shorted transmission time between waves(Ⅰ-Ⅲ andⅠ-Ⅴ) significant when compared to the control group.After surgery,the response thresholds of wave Ⅴand the peak latency of wave Ⅰwere normal in 46.7% children,the response threshold of wave Ⅴ were normal in 70.5% and slight abnormal in 29.5%.Occuring(elicit) rate of wave Ⅰwas 100% and peak latency of wave Ⅰwas normal in 50.2% chilren.The differrence of peak latencies(waves Ⅰ,Ⅲ andⅤ) and the response threshold of wave Ⅴ before surgery
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Objective To investigate the antagonist effects of sodium salicylate(NaSA) on the cisplatin(CDDP) induced hearing impairment in guinea pigs.Methods 60 guinea pigs were randomly divided into four groups: ①CDDP +NaSA(50 mg/kg) group,②CDDP +NaSA(100 mg/kg) group,③CDDP +NaSA(150 mg/kg) group and ④CDDP +NS(normal saline) control group.Auditory brainstem response(ABR) and distortion product otoacoustic emission(DPOAE) were used to evaluate their effects on hearing threshold and DPOAE amplitudes.Results The ABR responses of groupsⅠ,Ⅱ and Ⅲ were significantly lower than in the control group(P0.05).The ABR responses for group Ⅰ were significantly higher than group Ⅲ(P
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A hundred thirteen ears in 76 cases underwest the traumatic deafness caused by beating at the ear and head were examined with the Evoked Potential System of Nicolet Spirit and the Pure tone audiometry.113 ears were divided into two groups. One group consisted of 32 ears with the tympanal perforation, which were further divided into small, medium and big perforations. The second group consisted of 81 ears without tympanal perforation,which were classified into mild, moderate,serious,severe and profound deafness. The two groups were all examined by EcochG and ABR. The wave latent periods of EcochG and ABR of two groups (small, medium perforation;mild,moderate deafness)were statistically analysed and were compared with those of the normal control group. The results of the square deviation analysis and Q test showed the significant difference (76. 7%, P
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Objective: To investigate the cochlear function of the patients suffering from obstructive sleep apnea-hypopnea syndrome(OSAHS) by using ABR.Methods: 40 patients with OSAHS(80 ears) admitted from February 2004 to September 2004 were divided into two subgroups: mild OSAHS group(11 cases) and moderate and severe OSAHS group(29 cases)according to the value of AHI.Each group was tested by Auditory brainstem response(ABR).The latencies of wave Ⅰ、Ⅲ、Ⅴand the interpeak latency intervals of waveⅠ-Ⅲ、Ⅲ-Ⅴ、Ⅰ-Ⅴ were measured.The obtained results of the two subgroups were respectively compared with the normal values.Results: The latencies of waveⅠ、Ⅲ、Ⅴ and the interpeak latency intervals of wave Ⅰ-Ⅲ、Ⅰ-Ⅴin the moderate and severe OSAHS subgroup were prolonged compared with the normal control values,and the difference was significant statistically.The latencies of waveⅠ、Ⅲ in the moderate and severe OSAHS subgroup were significantly prolonged compared with those in the mild OSAHS subgroup.But there was no statistical change in the latencies of wave Ⅰ、Ⅲ、Ⅴand the interpeak latency intervals of waveⅠ-Ⅲ、Ⅲ-Ⅴ、Ⅰ-Ⅴin the mild OSAHS subgroup as compared with the normal control values.Conclusion: Cochlear function can be impaired in patients with moderate and severe OSAHS,and ABR can be taken as a monitor index to observe whether OSAHS affects cochlear function or not.
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We mainly disscused hearing impedimemt due to damage tothe tympanic membrane which is no more than 50 decibel of hearing loss with describing the signs of traumatic hearing loss, characteristics of its pathology and hearing tests on the basis of 40 eases with traumatic deafness coming to the forensic identification and the forensic identification of hearing Loss with objective data, What ABR audiometry is of great significance has been luther demonstrated in determining hearing Loss whith is supeuior to other hearing tests in distinguishing exaggeration and simulated desfness. We also analyzed rules for seriors hearing loss in Standard for Identifying serious Injury to Human Body(trial draft)from point of classification of hearing loss degree in clinics.