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Abstract Objective: In this study, we created an animal model to demonstrate the effects of thiamine on the hearing pathways of new-borns during pregnancy and lactation by inducing a dietary thiamine deficiency in the mother. Methods: The study included 16 female Wistar albino rats. The animals were separated into four groups and provided the appropriate amounts of dietary thiamine according to their groups during pre-pregnancy, pregnancy, and lactation periods. Three pups from each mother were included in the study, and 12 pups were selected from each group. On the fortieth day after birth, the auditory pathways of 48 pups in the 4 groups were examined electro physiologically and ultra-structurally. Results: In Group N-N, morphology of hair cells stereocilia degeneration was not obtained in all turns of cochlea. In Group N-T, Inner Hair Cells (IHCs) and Outher Hair Cells (OHCs) stereocilia didn't show degeneration in all turns of cochlea but had rupture inrows of HCs stereocilia. In group T-N IHCs stereocilia less degeneration was observed in all turns of cochlea. OHC stereocilia partial loss was observed only in basal turn of cochlea. In Group T-T IHCs stereocilia was observed less degeneration and rupture in all turns of cochlea. Conclusion: Thiamine is vital for the development of cochlear hair cells during both prenatal and postnatal periods. Even partial deficiency of thiamine causes significant degeneration to the auditory pathway. Level of evidence: The level of evidence of this article is 5. This article is an experimental animal and laboratory study.
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Cisplatin-related ototoxicity is a critical side effect of chemotherapy and can lead to irreversible hearing loss. This study aimed to assess the potential effect of the DNA methyltransferase (DNMT) inhibitor RG108 on cisplatin-induced ototoxicity. Immunohistochemistry, apoptosis assay, and auditory brainstem response (ABR) were employed to determine the impacts of RG108 on cisplatin-induced injury in murine hair cells (HCs) and spiral ganglion neurons (SGNs). Rhodamine 123 and TMRM were utilized for mitochondrial membrane potential (MMP) assessment. Reactive oxygen species (ROS) amounts were evaluated by Cellrox green and Mitosox-red probes. Mitochondrial respiratory function evaluation was performed by determining oxygen consumption rates (OCRs). The results showed that RG108 can markedly reduce cisplatin induced damage in HCs and SGNs, and alleviate apoptotic rate by protecting mitochondrial function through preventing ROS accumulation. Furthermore, RG108 upregulated BCL-2 and downregulated APAF1, BAX, and BAD in HEI-OC1 cells, and triggered the PI3K/AKT pathway. Decreased expression of low-density lipoprotein receptor-related protein 1 (LRP1) and high methylation of the LRP1 promoter were observed after cisplatin treatment. RG108 treatment can increase LRP1 expression and decrease LRP1 promoter methylation. In conclusion, RG108 might represent a new potential agent for preventing hearing loss induced by cisplatin via activating the LRP1-PI3K/AKT pathway.
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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 and analyze the diagnostic value of auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) in infants with secretory otitis media.@*Methods@#From June 2016 to June 2018, 65 infants (120 ears) with secretory otitis media who were treated at the First People's Hospital of Taizhou were selected.All the 120 ears were diagnosed by ABR wave test and DPOAE test machine.The results of different diagnostic methods were observed and compared.@*Results@#Among 65 cases (120 ears), 60 ears (50.00%) with mildly abnormality, 43 ears (35.83%) with moderate abnormality and 17 ears (14.17%) with normal ABR wave Ⅴ response threshold.There was no statistically significant difference in Ⅰ-Ⅴ wave interval between the mild abnormal group and the normal group (P>0.05), but Ⅰ-Ⅴ wave interval in the moderate abnormal group[(4.27±0.27)ms in moderate abnormal group] was significantly shorter than that in the normal group[(4.75±0.31)ms] and the mild abnormal group[(4.73±0.21)ms], the differences were statistically significant(t=5.949, 9.722, all P<0.05). The Ⅴ response threshold of bone-guided ABR wave was normal in 108 ears(90.00%, 108/120). The Ⅴ latency of bone guided wave was (8.16±0.22)ms, and abnormal in 12 ears (10.00%, 12/120). With the increase of the gas conduction reaction threshold, the bone conduction ABR reaction threshold also increased, but it was not as obvious as the air conduction.The wave Ⅴ latency in the normal BRT group was significantly lower than that in the abnormal group (compared with mild abnormal group, t=17.400, P<0.05; compared with moderate abnormal group, t=130.015, P<0.05). DPOAE test failed 86 ears (71.67%, 86/120), passed through 34 ears (28.33%, 34/120).@*Conclusion@#The latency of ABR wave I is sensitive to the diagnosis of secretory otitis media in infants.The combination of DPOAE and ABR is helpful to the early diagnosis of the disease.ABR and DPOAE tests have high value and are worthy of popularizing in clinic.
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Objective To study and analyze the diagnostic value of auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) in infants with secretory otitis media.Methods From June 2016 to June 2018,65 infants (120 ears) with secretory otitis media who were treated at the First People's Hospital of Taizhou were selected.All the 120 ears were diagnosed by ABR wave test and DPOAE test machine.The results of different diagnostic methods were observed and compared.Results Among 65 cases (120 ears),60 ears (50.00%) with mildly abnormality,43 ears (35.83%) with moderate abnormality and 17 ears (14.17%) with normal ABR wave Ⅴresponse threshold.There was no statistically significant difference in Ⅰ-Ⅴwave interval between the mild abnormal group and the normal group ( P ＞0.05 ), but Ⅰ -Ⅴ wave interval in the moderate abnormal group [( 4.27 ± 0.27)ms in moderate abnormal group ] was significantly shorter than that in the normal group [(4.75 ±0.31) ms] and the mild abnormal group [(4.73 ±0.21)ms],the differences were statistically significant (t＝5.949,9.722,all P＜0.05).TheⅤresponse threshold of bone -guided ABR wave was normal in 108 ears(90.00%,108／120).TheⅤlatency of bone guided wave was (8.16 ±0.22) ms,and abnormal in 12 ears (10.00%,12／120).With the increase of the gas conduction reaction threshold ,the bone conduction ABR reaction threshold also increased ,but it was not as obvious as the air conduction.The wave Ⅴ latency in the normal BRT group was significantly lower than that in the abnormal group ( compared with mild abnormal group , t ＝17.400,P ＜0.05;compared with moderate abnormal group,t＝130.015,P＜0.05).DPOAE test failed 86 ears (71.67%,86／120),passed through 34 ears (28.33%,34／120).Conclusion The latency of ABR wave I is sensitive to the diagnosis of secretory otitis media in infants.The combination of DPOAE and ABR is helpful to the early diagnosis of the disease.ABR and DPOAE tests have high value and are worthy of popularizing in clinic.
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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 investigate the auditory features in patients with severe obstructive sleep apnea hy-popnea syndrome(OSAHS) and the effects of continuous positive airway pressure (CPAP) on auditory functions . Methods Pure tone audiometry thresholds ,auditory brainstem responses (ABR) and distortion product otoacoustic emissions(DPOAE) were performed in three groups with 12 observed objects in each group ,which were the OS-AHS group(before and after treatment of CPAP) ,the simple snoring group and the normal control group .Results In the OSAHS group ,the high frequency auditory thresholds(at 8000 Hz) were greatly higher and the amplitudes of DPOAE reduced ;the detection rates of DPOAE were obviously declined .The peak latencies of Ⅰ ,Ⅲ and Ⅴ , and interpeak latencies of Ⅲ - Ⅴ andⅠ - Ⅴ were longer than those of in the other two groups .The differences were statistically significant(P<0 .05) .The differences of the interpeak latencies of Ⅰ - Ⅲ ,common pure tone au-ditory thresholds (125～4000 Hz) and the thresholds of Ⅴ -wave reaction in the OSAHS group did not change sig-nificantly compared with the other two groups(P>0 .05) .The amplitudes and the detection rates of DPOAEs (0 .5～8 kHz) increased after treatment with CPAP .The differences were statistically significant except the amplitudes of 500 ,750 and 1500 Hz (P<0 .05) .Pure tone audiometry and ABRs did not changed significantly after treatment with CPAP (P> 0 .05) .Conclusion The auditory functions of patients diagnosed with severe OSAHS were im-paired .Treatments with CPAP can partly improve the patients' auditory functions .
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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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BACKGROUND AND OBJECTIVES: Tinnitus is a common symptom in otolaryngology. While there have been some animal studies of unique findings in auditory brainstem response (ABR), there have not been much reports related to ABR waves and tinnitus. Recently, some human studies have been reported on the specific characteristics of ABR wave in tinnitus patients. In this study, we compared waveform characteristics of the tinnitus ear with those of non-tinnitus ear in unilateral tinnitus patients. SUBJECTS AND METHOD: A retrospective review was carried out for 101 patients, who had been enrolled from January 2011 to April 2016 for the treatment of unilateral tinnitus. ABR parameters between the tinnitus ear and the normal ear were compared. The entire population was divided into two groups, a right tinnitus group and a left tinnitus group, and each group was compared interaurally. RESULTS: Latency delay and amplitude differences were observed in the ipsilesional wave III, but the ratio differences were not significant. The right tinnitus patient group showed an increased amplitude but no latency delay in the wave III and V. The left tinnitus patient group showed a latency delay in the wave I, III, and V and a decreased amplitude difference in the wave III. CONCLUSION: When the ABR waveform of unilateral tinnitus patients were compared interaurally, different ABR characteristics were observed between the right and left tinnitus. This may raise the possibility of a different pathophysiologic mechanism between the right and left ear.
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Animals , Humans , Brain Stem , Ear , Evoked Potentials, Auditory, Brain Stem , Methods , Otolaryngology , Retrospective Studies , TinnitusABSTRACT
Objective To study the effect of chloral hydrate on click sound evoked auditory brainstem re-sponse (ABR) in healthy adult guinea pig .Methods A total of 20 healthy wild type albino male guinea pigs were se-lected for ABR assessment with click sound stimulation conscious and cholral hydrate anesthesia conditions .The ABR threshold was determined according to the wave that presents highest occurrence rate under different stimulus intensity .The latency ,interpeak latency of each wave at 90 dB peSPL stimulation as well as the amplitude of waveⅡ ,Ⅲ ,Ⅳ under different stimulus intensity were recorded .Results The ABR threshold in chloral hydrate anes-thesia was 25 .50 ± 2 .76 dB peSPL and at the waking state was 28 .5 ± 3 .66 dB peSPL from control group (P>0 .05) .The latencies of each wave recorded under chloral hydrate anesthesia state were prolonged compared to those of under waking state ,wave Ⅲ ,Ⅳ and Ⅴ had significance differences (P0 .05) .The interpeak latency between wave Ⅰ - Ⅴ ,Ⅲ - Ⅳ ,Ⅳ - Ⅴ in chloral hydrate anesthesia were longer compared to those of under waking state with significant differences (P 0 .05) .The amplitude and occurrence rate of wave Ⅱwere the highest among all the waves in both experimental group and control group .The amplitude of wave Ⅱ and Ⅲ in chloral hydrate anesthesia was higher than that of the waking state under acoustic stimulation conditions ofhigh intensity(P<0 .05) while the amplitude of wave Ⅳ was lower than the waking state (P<0 .05) .Conclusion The chloral hydrate anesthesia may be able to apparently lengthen the ABR latencies of wave Ⅲ ,Ⅳ ,Ⅴ and affect the amplitude .This effect should be considered during the assessment of ABR under anesthesia state in guinea pig ;The ABR threshold of guinea pig could be determined according to the wave Ⅱ because it 's highest occurrence rate .
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Objective To investigate the relationships of tone burst -ABR Thresholds and the pure -tone audiograms in normal hearing adults .Methods The response thresholds of Tone burst -ABR and the pure -tone audiogram were recorded from 34 adult(68 ears) at 0 .5 ,1 .0 ,2 .0 ,and 4 .0 kHz .The results were statistically ana-lyzed .The correlation of the response thresholds of tone burst -ABR and the pure-tone audiogram were studied . Results At 0 .5 ,1 .0 ,2 .0 ,4 .0 kHz ,the averages of the response thresholds of tone burst -ABR were 27 .43 ± 3 .29 ,25 .98 ± 2 .76 ,16 .78 ± 2 .37 ,and 12 .42 ± 2 .64 dB nHL ,respectively .The averages of the pure -tone audio-gram were 12 .23 ± 3 .99 ,11 .82 ± 2 .56 ,9 .58 ± 3 .23 ,and 9 .92 ± 2 .59 dB nHL ,respectively .The differences between the response thresholds of tone burst -ABR and the pure-tone audiogram were 12 .13 ± 4 .51 ,11 .43 ± 3 .66 ,7 .61 ± 2 .43 ,and 7 .17 ± 1 .32 dB ,respectively .At 0 .5 ,1 .0 ,2 .0 ,and 4 .0 kHz ,Pearson correlation coefficients were 0 .69 ,0 .79 ,0 .84 ,0 .89 ,respectively .Conclusion The tone burst -ABR and the pure -tone audiogram thresholds were a highly correlated with each other ,especially at 2 .0 kHz and 4 .0 kHz .Tone burst -ABR has the frequency specificity ,which can response the hearing level better .
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Objective To study the potential roles of acoustic immittance,distortion product otoacoustic e-mission (DPOAE),and the brainstem response audiometry (ABR)in the diagnosis of children with acute non-sup-purative otitis media (AN-SOM).Methods A retrospective analysis was administered to 182 cases with AN-SOM at the otolaryngology department between March 2014 and March 2015.We compared the results of the acous-tic immitance of 218 symptomatic ears and 146 asymptomatic ears,and also the proportion of DPOAE abnormity and ABR abnormity.We analyzed the specialty of symptomatic ears and asymptomatic ears in 3 terms of audiology test results.Results The proportions of abnormal tympanograms,DPOAE,ABR for symptomatic ear were 64.7%, 72.0%,and 57.8%,which were significantly higher than those of in 41.8%,39.7%,and 35.6% in asymptomatic ear.The difference were statistically significant(P<0.05).A further analysis of audiologic results showed that at least one abnormal result was as high as 196 ears (89.9%)in the asymptomatic ear,90 ears (61.6%)showed no symptoms.The differences were statistically significant(P<0.05).The results of audiology tests showed that tym-panograms in symptomatic ears showed diversity,that were 60.6% for type B or C,35.3% for type A,4.1% for the As.Conclusion The early detections by using acoustic immitance,DPOAE and ABR are very important to the diagnosis of children with acute non-suppurative otitis media.It can improve the sensitivity,and reduce the misdi-agnosis.
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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 investigate the characteristics of auditory nerves and brainstem pathways,patho-physiological and nerve damages and the correlation between oxygen indexes,and the values of high stimulation ABR in patients with OSAHS.Methods Auditory brain stem responses (ABR)at rates of 11.1 times/s,31.1 times/s,51.1 times/s were performed in both the moderate-to-severe OSAHS group(5 cases of moderate and 34 cases of severe,in total of 39 cases ,78 ears)and the control group (34 cases,68 ears).According to the character-istics of ABR,the correlation with parameters of blood oxygen was studied.Results At the rate of 11.1 times/s, wave V latencies (5.79±0.22 ms)in OSAHS patients were longer than that in the control group.At the rate of 31.1 times/s,wave V latencies (5.98±0.19 ms)and waveⅠ(1.85±0.18 ms)in OSAHS patients were prolonged more than those in the control group.At the rate of 51.1 times/s,wave V latencies (6.09±0.25 ms)and waveⅠ(1.94±0.26 ms)in OSAHS patients were longer than those in the control group.Increasing stimulation rates from 11.1 times/s to 31.1 times/s showedΔⅠwas longer in OSAHS group(0.12±0.17 ms)than in the control group (0.07±0.11 ms).Increasing stimulation rates from 11.1 times/s to 51.1 times/s showedΔⅠwas longer in OS-AHS group(0.21±0.25 ms)than in the control group(0.15±0.10 ms).All above had correlations with hypoxia. Conclusion High stimulation rates in ABR by amplifying the waveⅠ latency confirm cochlear and auditory nerve damages near the cochlear segment in patients with moderate to severe OSAHS.Therefore the study of nerve injury in OSAHS patients should take blood oxygen saturation and hypoxia percentage rather than AHI.
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Objective:To investigate the effects of Ligustrazine (TMP) on the expression of caspase-3 and ABR threshold in guinea pig cochlea after gentamicin (GM) ototoxicity. Methods:A total of 80 guinea pigs were randomly divided into saline group, GM group, GM+TMP group and TMP group. The duration of treatment was lasted 10 d continuously in all groups. The dose was decided by their weight. The ABR threshold were measured before and after administration of 10 d. SABC immunohistochemical method was used to detect the expression of caspase-3 in the spiral ganglion,cochlea hair cells,and stria vascularis of guinea pigs. Results:(1) The average gray value in the spiral ganglion cells, stria vascularis and hair cells in GM group had significant difference with those in the same position of control group (P<0.05) .The average gray value in the spiral ganglion cells and hair cells in GM+TMP group had no difference with those in the same position of control group (P>0.05), but in stria vascularis (P<0.05) . Meanwhile the average gray value in spiral ganglion, hair cells, stria vascularis in TMP+GM group had significant difference with those in GM group (P<0.05) . (2) The ABR threshold had no significant differences before treatment (P>0.05) . After administration of 10 d, the ABR threshold of GM group was significantly changed (P<0.05) . The ABR thresholds in GM group was significantly higher than that in control group (P<0.05) . The ABR threshold in TMP+GM group was lower than that in GM group (P<0.05) . Conclusion:TMP participates in preventing the process of cochlea injury caused by GM,through blocking the expression of caspase-3 in cochlea tissue of GM ototoxicosis probably,which achieve the protection of GM deafness eventually.
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Objective To study the normal ranges and features for click-auditory brainstem responses of children in 3~5 years old.Methods Normal results of click-ABR from 132 normal children (224 ears)were ana-lyzed.The children were divided into three groups:Group A (74 ears from children of 3 years old),Group B (78 ears from children of 4 years old)and Group C (72 ears from children of 5 years old).The ABR data were statisti-cally analyzed by ANOVA with SPSS.Results At 80 dB nHL,the wave Ⅰ,Ⅲ,and Ⅴ latencies and intervals of wave Ⅰ- Ⅲ,and wave Ⅰ-Ⅴ of ABR for 3 -year old children were 1.24 ±0.09 ms,3.53 ±0.16 ms,5.39 ± 0.23 ms,2.30±0.15ms and 4.15 ±0.22 ms,respectively,and for 4 -year-old children,they were1.23 ±0.10 ms,3.52±0.39 ms,5.30±0.21 ms,2.28±0.39 ms and 4.07 ±0.22 ms,respectively.For 5 - year-old chil-dren,they were1.24±0.10 ms,3.67±0.63 ms and 5.34±0.19 ms,2.42±0.63 ms and 4.09±0.19 ms,respec-tively.The thresholds for 3-year children were 22.57 ±4.40 dB nHL,for 4 - year children,21.15 ±4.83 dB nHL,and for 5 - year children,21.11±3.48 dB nHL.Among three groups,only latency of wave V and interval of wave I-V had statistical differences,and a further analysis showed the statistical differences in Groups A and B. No statistical differences were observed in Groups B and C.The latency of wave I and thresholds of ABR for the children of different ages were not significantly different.Conclusion The resvits of this study suggest the brainstem may mature at 4 years old.
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BACKGROUND AND OBJECTIVES: Auditory brainstem response (ABR) is a noninvasive measurement of a stimulus-locked, synchronous electrical event. ABR provides information concerning the functional integrity of brainstem nuclei. Age is a key factor in the interpretation of ABR peak latency among different age groups. Progressively with time it follows a "maturation pattern" during which latencies decrease. Wave V is very prominent and reliable for detection of threshold in children. The present study was performed to see the effect of age related auditory maturation on ABR wave V latency in children. SUBJECTS AND METHODS: The study involved 80 subjects ranging in age from birth to 12 years. The subjects were divided equally into eight age groups. ABR were elicited by an acoustic click stimuli, brainstem responses collected through electrode and recorded at the same time. Latency of wave V was acknowledged. RESULTS: Wave V latency decreased rapidly in early childhood, became slower after 3 years of age and completely matured by 12 years of age. There was no significant difference in latency of wave V between the ears with age. CONCLUSIONS: There is a distinct maturation pattern of wave V latency in ABR for both ears. ABR is a reliable test to assess the functional maturation of wave V in children.
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Child , Humans , Acoustics , Brain Stem , Ear , Electrodes , Evoked Potentials, Auditory, Brain Stem , ParturitionABSTRACT
BACKGROUND AND OBJECTIVES: Hyperbillirubinemia in infants have been associated with neuronal damage including in the auditory system. Some researchers have suggested that the bilirubin-induced auditory neuronal damages may be temporary and reversible. This study was aimed at investigating the auditory neuropathy and reversibility of auditory abnormalities in hyperbillirubinemic infants. SUBJECTS AND METHODS: The study participants included 41 full term hyperbilirubinemic infants (mean age 39.24 days) with normal birth weight (3,200-3,700 grams) that admitted in hospital for hyperbillirubinemia and 39 normal infants (mean age 35.54 days) without any hyperbillirubinemia or other hearing loss risk factors for ruling out maturational changes. All infants in hyperbilirubinemic group had serum bilirubin level more than 20 milligram per deciliter and undergone one blood exchange transfusion. Hearing evaluation for each infant was conducted twice: the first one after hyperbilirubinemia treatment and before leaving hospital and the second one three months after the first hearing evaluation. Hearing evaluations included transient evoked otoacoustic emission (TEOAE) screening and auditory brainstem response (ABR) threshold tracing. RESULTS: The TEOAE and ABR results of control group and TEOAE results of the hyperbilirubinemic group did not change significantly from the first to the second evaluation. However, the ABR results of the hyperbilirubinemic group improved significantly from the first to the second assessment (p=0.025). CONCLUSIONS: The results suggest that the bilirubin induced auditory neuronal damage can be reversible over time so we suggest that infants with hyperbilirubinemia who fail the first hearing tests should be reevaluated after 3 months of treatment.