Objective:This study aims to investigate the mechanism and potential effects of two exposures to 100 dB sound pressure level（SPL） broadband white noise, with a 14-days interval, on the myelin sheath of the cochlear auditory nerve in mice. The research provides experimental evidence for understanding the pathophysiological processes of noise-induced hearing loss and hidden hearing loss. Methods:Fifteen 6-week-old male C57BL/6J mice with normal hearing thresholds were randomly divided into three groups: a control group（no noise exposure）, a single noise exposure group, and a double noise exposure group. The single noise exposure group was exposed to 100 dB SPL white noise for 2 hours, and ABR thresholds were measured 1 day（P1） and 14 days（P14） after the exposure. The double noise exposure group was exposed to the same conditions of 100 dB SPL white noise for 2 hours, followed by a second identical exposure 14 days later. ABR thresholds were measured 1 day（P15） and 14 days（P28） after the second exposure. The cochleae of all three groups were then collected for immunofluorescence observation of the basilar membrane and transmission electron microscopy to observe changes in the structure of the auditory nerve myelin sheath. Results:In the single noise exposure group, ABR thresholds at all frequencies were significantly elevated compared to the control group at P1. There were no significant changes in ABR thresholds at any frequency at P14. In the double noise exposure group, ABR thresholds at all frequencies were significantly elevated compared to the control group at P15 and P28（P<0.001）. After the first noise exposure, immunofluorescence observation revealed no significant weakening of the auditory nerve myelin sheath signal; transmission electron microscopy showed no significant changes in myelin sheath morphology. However, after the second noise exposure, immunofluorescence observation revealed a weakening of the myelin sheath signal, and transmission electron microscopy showed thinning of the myelin sheath, disruption of the lamellar structure, and separation from the axon, indicating demyelination. Conclusion:Two exposures to 100 dB SPL broadband white noise can lead to damage to the auditory nerve myelin sheath in mice, whereas a single exposure does not cause significant changes.
Animals ; Male ; Myelin Sheath/pathology* ; Mice ; Cochlear Nerve/pathology* ; Mice, Inbred C57BL ; Noise/adverse effects* ; Hearing Loss, Noise-Induced/physiopathology* ; Cochlea ; Evoked Potentials, Auditory, Brain Stem

Objective:To investigate the impact of Waardenburg syndrome（WS） -associated Sox10 p.S100Rfs*9 mutation on inner ear function and its mechanism in noise-induced hearing impairment. Methods:A mice model carrying the Sox10 p.S100Rfs*9 mutation was established using CRISPR-Cas9 gene editing technology. Auditory phenotypes were assessed under baseline conditions and after noise exposure（96 dB SPL, 2 hours）. Auditory brainstem response（ABR） tests were performed to evaluate hearing function, combined with immunofluorescence staining of cochlear basilar membrane whole-mounts to observe hair cells and ribbon synapses. Transcriptome sequencing was conducted to analyze molecular mechanisms. Results:Sox10 p.S100Rfs*9 heterozygous mice exhibited normal hearing thresholds with characteristic ventral pigmentation abnormalities under baseline conditions. Following noise exposure, mutant mice showed significantly higher ABR thresholds at 24 000 Hz compared to wild-type controls（[60.00±6.12]vs[48.13±4.28]dB SPL, P<0.000 1）, and a significant reduction in ribbon synapses（CtBP2-positive puncta） in the basal turn（[55.0±2.3]vs[64.8±3.3]per inner hair cell, P=0.006 6）, while hair cell morphology and number remained intact. Transcriptome analysis revealed altered expression of genes involved in immune regulation, membrane structures, ion channels, and neuroactive ligand-receptor interactions. Conclusion:The Sox10 p.S100Rfs*9 mutation does not alter baseline hearing function but significantly increases inner ear susceptibility to noise damage, primarily manifested as enhanced ribbon synapse vulnerability, especially in high-frequency regions. This gene-environment interaction reveals that Sox10 haploinsufficiency may compromise noise tolerance by affecting synaptic stability and inner ear protective mechanisms. These findings provide new perspectives on the phenotypic heterogeneity in WS patients and theoretical basis for individualized noise protection strategies for patients carrying SOX10 mutations.
Animals ; SOXE Transcription Factors/genetics* ; Waardenburg Syndrome/physiopathology* ; Mice ; Hearing Loss, Noise-Induced/genetics* ; Evoked Potentials, Auditory, Brain Stem ; Mutation ; Noise ; Disease Models, Animal ; Ear, Inner/physiopathology*

Objective:To investigate the application value of NB CE-Chirp ASSR in the assessment of hearing threshold in children with hearing impairment. Methods:The hearing test results of 44 children with sensorineural hearing loss（88 ears） diagnosed in Shanghai Children's Hospital from January 2023 to December 2023 were retrospectively studied, including 19 ears in mild hearing loss group, 26 ears in moderate group, 20 ears in severe group and 23 ears in extremely severe group. Correlations between auditory brainstem response（ABR） thresholds, pure tone audiometry（PTA） thresholds and NB CE-Chirp ASSR response thresholds in different hearing loss groups were analyzed. Results:The threshold difference between ABR and NB CE-Chirp ASSR（2 000-4 000 Hz） was between 0.50-4.08 dB in different degrees of hearing loss group. There was a significant correlation between NB CE-Chirp ASSR and ABR response threshold in each group（P<0.001）, and the correlation coefficients of mild, severe and extremely severe groups were all greater than 0.8, showing a strong correlation. The average threshold difference between PTA and NB CE-Chirp ASSR in each group was between 1.88-3.91 dB. The correlation coefficients were all greater than 0.8, showing a strong correlation. The difference between PTA and NB CE-Chirp ASSR response threshold at 500, 1 000, 2 000 and 4 000 Hz in each groupwas between 0.25-3.84 dB. With the increase of frequency, the correlation coefficient between PTA and NB CE-Chirp ASSR response threshold showed an upward trend. The frequency with the highest coefficient was 4 000 Hz, and the r values were all greater than 0.9, followed by 2 000 Hz, and the correlation coefficient was relatively low at 500 Hz. In the extremely severe group, each frequency coefficient was greater than 0.7, showing a strong correlation. Conclusion:NB CE-Chirp ASSR has good frequency specificity and can reliably assess hearing thresholds in hearing-impaired children.
Humans ; Auditory Threshold ; Child ; Retrospective Studies ; Female ; Male ; Audiometry, Pure-Tone/methods* ; Evoked Potentials, Auditory, Brain Stem ; Child, Preschool ; Hearing Loss, Sensorineural/physiopathology* ; Adolescent

In this study, we aimed to (1) identify white matter (WM) deficits underlying the consciousness level in patients with disorders of consciousness (DOCs) using diffusion tensor imaging (DTI), and (2) evaluate the relationship between DTI metrics and clinical measures of the consciousness level in DOC patients. With a cohort of 8 comatose, 8 unresponsive wakefulness syndrome/vegetative state, and 14 minimally conscious state patients and 25 patient controls, we performed group comparisons of the DTI metrics in 48 core WM regions of interest (ROIs), and examined the clinical relevance using correlation analysis. We identified multiple abnormal WM ROIs in DOC patients compared with normal controls, and the DTI metrics in these ROIs were significantly correlated with clinical measures of the consciousness level. Therefore, our findings suggested that multiple WM tracts are involved in the impaired consciousness levels in DOC patients and demonstrated the clinical relevance of DTI for DOC patients.
Adult ; Brain Stem ; diagnostic imaging ; Consciousness ; physiology ; Consciousness Disorders ; diagnostic imaging ; pathology ; Diffusion Tensor Imaging ; methods ; Female ; Humans ; Image Processing, Computer-Assisted ; methods ; Male ; Middle Aged ; White Matter ; pathology ; physiopathology

Carrier Proteins ; genetics ; Evoked Potentials, Auditory, Brain Stem ; Humans ; Infant ; Iron Metabolism Disorders ; genetics ; physiopathology ; Male ; Mutation ; Neuroaxonal Dystrophies ; genetics ; physiopathology ; Spasms, Infantile ; genetics ; physiopathology

OBJECTIVETo study the audiological and otological status of cleft palate infants with the application of distortion product otoacoustic emission (DPOAE), auditory brainstem response (ABR), tympanometry with 1000 Hz and 226 Hz probe tones.

METHODSTotally 45 cleft palate infants aged 8-24 months were included in the study. Most of them were examined for DPOAE, ABR and two frequency tympanometry.

RESULTSMost infants failed the three tests,among whom 6.7% ears passed DPOAE and 33.3% of ears had normal ABR hearing threshold. In addition, 8.9% of ears turned out normal in the 1000 Hz probe-tone tympanometry, and 13.3% were type A in the 226 Hz probe-tone tympanometry. Finally, 1000 Hz tympanometry had more agreement with DPOAE and latency of ABR wave I than 226 Hz tympanometry.

CONCLUSIONMost cleft palate infants have audiological and otological problems, which should be evaluated in a more comprehensive manner.

Acoustic Impedance Tests ; Cleft Palate ; physiopathology ; Evoked Potentials, Auditory, Brain Stem ; Humans ; Infant ; Infant, Newborn ; Neonatal Screening ; Otoacoustic Emissions, Spontaneous

BACKGROUNDThe prevalence of sudden sensorineural hearing loss in children (CSSNHL) is consistently increasing. However, the pathology and prognosis of CSSNHL are still poorly understood. This retrospective study evaluated clinical characteristics and possible associated factors of CSSNHL.

METHODSOne hundred and thirty-six CSSNHL patients treated in Department of Otolaryngology-Head and Neck Surgery and Institute of Otolaryngology at Chinese PLA General Hospital between July 2008 and August 2015 were included in this study. These patients were analyzed for clinical characteristics, audiological characteristics, laboratory examinations, and prognostic factors.

RESULTSAmong the 136 patients (151 ears), 121 patients (121 ears, 80.1%) were diagnosed with unilaterally CSSNHL, and 15 patients (30 ears, 19.9%) with bilateral CSSNHL. The complete recovery rate of CSSNHL was 9.3%, and the overall recovery rate was 37.7%. We found that initial degree of hearing loss, onset of treatment, tinnitus, the ascending type audiogram, gender, side of hearing loss, the recorded auditory brainstem response (ABR), and distortion product otoacoustic emissions (DPOAEs) had prognostic significance. Age, ear fullness, and vertigo had no significant correlation with recovery. Furthermore, the relevant blood tests showed 30.8% of the children had abnormal white blood cell (WBC) counts, 22.1% had elevated homocysteine levels, 65.8% had high alkaline phosphatase (ALP), 33.8% had high IgE antibody levels, and 86.1% had positive cytomegalovirus (CMV) IgG antibodies.

CONCLUSIONSCSSNHL commonly occurs unilaterally and results in severe hearing loss. Initial severe hearing loss and bilateral hearing loss are negative prognostic factors for hearing recovery, while positive prognostic factors include tinnitus, gender, the ascending type audiogram, early treatment, identifiable ABR waves, and DPOAEs. Age, vertigo, and ear fullness are not correlated with the recovery. Some serologic indicators, including the level of WBC, platelet, homocysteine, ALP, positive CMV IgG antibody, fibrinogen, and some immunologic indicators, are closely related to CSSNHL.

Adolescent ; Child ; Child, Preschool ; Evoked Potentials, Auditory, Brain Stem ; Female ; Hearing Loss, Sensorineural ; blood ; etiology ; physiopathology ; Humans ; Male ; Otoacoustic Emissions, Spontaneous ; Retrospective Studies

OBJECTIVETo explore the effects of electrical stimulation at acupoints in the distribution area of auricular vagus nerve combined with sound masking on auditory brainstem response (ABR) and contents of neurotransmitters of γ-aminobutyric acid (γ-GABA), 5-hydroxytryptamine (5-HT) and acetyl choline (Ach) in inferior colliculus of tinnitus rats.

METHODSTwenty-four male adult SD rats were randomized into a control group, a model group, a 7-d treatment group and a 15-d treatment group. Except the control group, rats in the remaining groups were treated with intraperitoneal injection of 10% salicylate sodium at a dose of 350 mg/kg to establish tinnitus model. Rats in the control group were treated with injection of 0.9% NaCl. Rats in the 7-d treatment group and 15-d treatment group were treated with electrical stimulation at "Shenmen (TF₄)" and "Yidan (CO₁₁)" in the distribution area of auricular vagus nerve combined with sound masking, once a day, for 7 days and 15 days. The SigGenRP software of TDT system was applied to provide voice for single ear and collect the signal, and the voice threshold of ABR was tested. The levels of γ-GABA, 5-HT and Ach in inferior colliculus of rats were detected by enzyme linked immunosorbent assay (ELISA) and compared.

RESULTSCompared with the model group, the threshold values of ABR in 12 kHz and 16 kHz voice stimulation in the 7-d treatment group were significantly lower all P < 0.05); the threshold values of ABR from 4 kHz to 28 kHz voice stimulation in the 15-d treatment group were signally reduced (P < 0.05, P < 0.01), which was more significant than those in the 7-d treatment group. The level of γ-GABA in the model group was significantly lower than that in the control group (P < 0.05), and that in the 15-d treatment group was apparently higher than that in the model group (P < 0.05). The level of 5-HT in the model group was markedly higher than that in the control group (P < 0.05), and that in the 7-d treatment group was lower than that in the model group (P < 0.05), while that in the 15-d treatment group was apparently higher than that in the model group (P < 0.05). The level of Ach in the model group was obviously; lower than that in the control group (P < 0.05), and that in the 7-d treatment group was higher than that in the model group (P < 0.05).

CONCLUSIONElectrical stimulation at auricular vagus nerve combined with sound masking) could regulate the threshold of ABR, especially in the 15-d treatment group. This may be ascribed to modulating the levels of neurotransmitter of γ-GABA, 5-HT and Ach in inferior colliculus.

Acupuncture Points ; Animals ; Brain Stem ; physiopathology ; Electric Stimulation ; Evoked Potentials, Auditory, Brain Stem ; Humans ; Inferior Colliculi ; physiopathology ; Male ; Neurotransmitter Agents ; metabolism ; Rats ; Rats, Sprague-Dawley ; Serotonin ; metabolism ; Tinnitus ; physiopathology ; therapy ; Vagus Nerve ; physiopathology ; gamma-Aminobutyric Acid ; metabolism

OBJECTIVETo compare the differences in the efficacy on speech and swallowing dysfunction of medulla oblongata palsy (MOP) after brainstem infarction between electroacupuncture at eight-neck-occiput points and routine acupoints.

METHODSSeventy-two patients were randomized into a neck-occiput points group and a meridian points group, 36 cases in each one. In the neck-occiput points group, the eight-neck-occiput points (Neck 1-4 points, Occiput 1-4 points) were selected. In the meridian points group, Lianquan (CV 23), Futu (LI 18), Tongli (HT 5), Hegu (LI 4) and the others were selected. Electroacupuncture was used in the two groups, dense-dispersion wave, retaining for 30 min. The treatment was given once a day, 5 treatments a week. Totally, 4 weeks were required. The symptom scores of speech and swallowing dysfunction were observed before and after treatment in the two groups. The efficacy was compared between the two groups.

RESULTSThe scores of speech and swallowing dysfunction were improved significantly after treatment in the two groups (P < 0.05, P < 0.01). The results in the neck-occiput points group were better than those in the meridian points group (both P < 0.01). The curative rate of speech dysfunction was 30.6% (11/36) and that of swallowing dysfunction was 22.2% (8/ 36) in the neck-occiput points group, which were better than 11.1% (4/36) and 5.6% (2/36) in the meridian points group, respectively. The differences were significant in comparison of the two groups (P < 0.01, P < 0.05).

CONCLUSIONElectroacupuncture at eight-neck-occiput points achieves a better efficacy on speech and swallowing dysfunction of MOP after brainstem infarction as compared with the routine acupoints. This therapy is characterized as more accurate point localization and safer operation.

Acupuncture Points ; Adult ; Aged ; Brain Stem Infarctions ; complications ; Bulbar Palsy, Progressive ; etiology ; physiopathology ; therapy ; Deglutition ; Electroacupuncture ; Female ; Humans ; Male ; Medulla Oblongata ; physiopathology ; Middle Aged

OBJECTIVE: To observe the change of auditory brainstem response (ABR) in hearing deprivation rat model induced by bilateral cochlears ablation at different time points. METHOD: Forty SD rats were randomly divided into four experiment groups including 2-week group, 4-week group, 6-week group, 8-week group and four control groups with 5 rats (n = 10) in each group. Then bilateral cochlears ablation was applied to experiment groups. The threshold value of ABR was measured at different time and latent period of each wave was compared. RESULT: The threshold of ABR in experiment group was elevated significantly. The latent period of each wave was pro longed significantly (P < 0.01). In experiment group, the threshold value of ABR in 2-week and 4-week group was significantly greater than that in 6-week group and 8-week group (P < 0.01). CONCLUSION Bilateral cochlears ablation surgery could elevate the threshold of ABR and latent period of each wave prolonged. The effect of hearing deprivation became apparent after surgery for 4 weeks.
Animals ; Auditory Threshold ; Cochlea ; physiopathology ; surgery ; Disease Models, Animal ; Evoked Potentials, Auditory, Brain Stem ; physiology ; Hearing Loss ; Male ; Rats ; Rats, Sprague-Dawley