[Evaluation of the outcomes of cochlear implant in children with auditory neuropathy].

Objective: To investigate the auditory and speech abilities of children with congenital auditory neuropathy (AN) after cochlear implant (CI), and to analyze the role of genetic testing in predicting the postoperative outcomes of CI in AN patients. Methods: Fourteen children diagnosed with AN by audiological battery test and underwent CI surgery in Xijing Hospital of the Air Force Medical University from 2002 to 2021 were included in this study (9 males and 5 females), with an implantation age of (3.1±1.7) years (mean±standard deviation, the same as follows). The preoperative audiological results and deafness gene results were analyzed. Another 52 children with ordinary sensorineural hearing loss (SNHL) were selected as the control group (30 males and 22 females), with an implantation age of (2.2±0.9) years. The demographic factors such as age and gender were matched with those of the AN group. The modified Category Auditory Performance (CAP-Ⅱ) and Speech Intelligence Rate (SIR) were used to evaluate the development of postoperative auditory and speech abilities in two groups. The Mandarin Speech Test System was used to test the speech recognition rate of monosyllabic and disyllabic words and sentences. Matlab 2022 software was used to analyze the data. Results: The results of gene in 14 children with AN showed that 6 cases had OTOF gene mutations, 2 cases (siblings) were confirmed to have TNN gene mutations through whole exome sequencing, and the remaining 6 cases were not find any clear pathogenic gene mutations. All subjects underwent CI surgery with electrodes implanted into the cochlea smoothly, and there were no postoperative complications. After surgery, all AN children had improved auditory and speech abilities, but only 64% (9/14) of AN children with CI had auditory ability scores comparable to the control group of SNHL children (including 2 children with TNN gene mutations), and 36% (5/14) of AN children had lower scores than the control group of SNHL children.The average speech recognition rate of two children with TNN gene mutations was 86.5%, and of two children with OTOF gene mutations was 83.2%. Conclusions: AN children achieved varying degrees of auditory and speech abilities after CI, but the postoperative effects varied greatly. Some children achieved similar results as ordinary SNHL children, but there were still some children whose effects were worse than those of ordinary SNHL children. The postoperative efficacy of CI in two children with AN caused by TNN pathogenic genes were comparable to that of ordinary SNHL in children. Genetic testing had certain reference value for predicting the postoperative effect of CI in AN children.

[Study on the clinical characteristics of auditory neuropathy patients with normal pure tone average or mild hearing loss].

Objective: The purpose of this study was to analyze the clinical characteristics of auditory neuropathy (AN) patients with normal hearing or mild hearing loss. Methods: Data from Multicenter Study on Clinical Diagnosis and Intervention of Acoustic Neuropathy (registration number: ChiCTR2100050125). According to the Chinese clinical practice guideline of auditory neuropathy (version 2022), these patients divided into two groups: the normal hearing group (PTA Normal, PTAN group, the average hearing threshold<20 dB HL) and the mild hearing loss group (PTA Mild hearing loss, PTAM group, the average hearing threshold between 20-35 dBHL). The audiology characteristics, clinical features, and follow-up were analyzed. Data analysis was conducted using GraphPad Prism 8 and SPSS 20.0 software. Results: A total of 75 AN with normal hearing or mild hearing loss were included in this study. The PTAN group consisted of 19 patients (38 ears), including 12 males and 7 females. The average onset age was (16.9±4.5) years old, while the test age was (22.1±5.8) years old for PTAN group. The PTAM group consisted of 56 patients (112 ears), including 29 males and 27 females. The average onset age was (16.2±7.9) years old, while the test age was (23.9±9.0) yeas old for PTAM group. The average hearing threshold of low frequency (0.125-0.5 kHz) was significantly decreased. ABR disappeared in 86.00% (126/150) of the patients. The speech recognition rate was 71.80±22.44% in the PTAN group and 58.08±29.28% in the PTAM group.-SP/AP was 0.98±0.47 in the PTAN and 1.07±0.63 in PTAM group; 40 (53.33%) patients had tinnitus. 29 patients (58 ears) were followed up, including 10 patients (20 ears) in the PTAN group and 19 patients (38 ears) in the PTAM group. There was no significant change in hearing threshold in short-term follow-up (<3 years). With the extension of the disease duration (>3 years), the PTAN group tended to decrease at low frequency, and the PTAM group decreased at high frequency first. The hearing threshold at 0.25 kHz in the PTAN group and 4 kHz in the PTAM group decreased significantly. Conclusions: AN patients with normal hearing or mild hearing loss exhibit abnormal results in audiological examination results, including ABR, electrocochleography and speech discrimination score. A combination of audiological tests should be used to make the diagnosis of AN. With the progression of the disease, AN with normal hearing or mild hearing loss tends to decrease.

[Recognition of unilateral auditory neuropathy in children].

Objective: This study aimed to compare the audiological characteristics between children with unilateral auditory neuropathy (UAN) and single-sided deafness (SSD) to establish a valid basis for the differential diagnosis of children with UAN. Methods: A retrospective analysis was conducted on audiological and imaging evaluations of children with UAN and SSD who were treated at Beijing Children's Hospital of Capital Medical University between May 2015 and June 2023. There were 17 children with UAN, comprising 10 males and 7 females, with an average age of 4.7 years. Additionally, there were 43 children with SSD, consisting of 27 males and 16 females, with an average age of 6.5 years. Audiological assessments included Auditory brainstem response (ABR), Steady-state auditory evoked potential (ASSR), Behavioural audiometry, Cochlear microphonic potential (CM), Distortino-product otoacoustic emission (DPOAE), and acoustic immittance test. The results of the audiological assessment and imaging phenotypic between the two groups of children were compared and analyzed by applying SPSS 27.0 statistical software. Results: (1) The UAN group (77.8%) had a significantly higher rate of ABR wave IIIL than the SSD group (20.9%) (P<0.01). The PA thresholds at 500 Hz and 1 000 Hz of children with SSD were higher than those of children with UAN, while the ASSR thresholds at 500 Hz, 1000 Hz, 2 000 Hz, and 4 000 Hz of children with SSD were significantly higher than those of children with UAN (P<0.05). (2) The degree of hearing loss in both UAN and SSD children was predominantly complete hearing loss. The percentage of complete hearing loss was significantly higher (χ²=4.353, P=0.037) in the SSD group (93.0%, 40/43) than in the UAN group (63.6%, 7/11). However, the percentage of profound hearing loss was significantly higher in the UAN group (27.3%, 3/11) than in the SSD group (2.3%, 1/43) (Fisher's exact test, P=0.023). In terms of hearing curve configuration, the percentage of flat type was significantly higher in the SSD group (76.7%, 33/43) than in the UAN group (36.4%, 4/11). The proportion of the UAN group (27.3%, 3/11) was significantly higher than that in the SSD group (2.3%, 1/43) in ascending type (P<0.05). There were no statistically significant differences in the hearing curves of the declining type and other types between the two groups (P>0.05). (3) The proportion of imaging assessment without abnormality was significantly more common in the UAN group (81.8%) than in the SSD group (37.1%) (χ²=6.695, P=0.015). Conclusions: Compared to children with SSD, the occurrence of wave IIIL on the ABR test was significantly more common in children with UAN. The percentage of ascending hearing curves was significantly higher in children with UAN than in children with SSD. ASSR thresholds were significantly lower in children with UAN. The normal imaging phenotype was significantly more common in children with UAN than in children with SSD.

[The updates of the ACMG variant interpretation guidelines affect the pathogenicity determination of OTOF gene variations in patients with auditory neuropathy].

Objective: To compare the differences between the variation interpretation standards and guidelines issued by the American College of Medical Genetics and Genomics (ACMG) and the Association for Molecular Pathology (AMP) in 2015 (The 2015ACMG/AMP guideline) and the Deafness Specialist Group of the Clinical Genome Resource (ClinGen) in 2018 for hereditary hearing loss (Healing loss, HL) issued the expert specification of the variation interpretation guide (The 2018 HL-EP guideline) in evaluating the pathogenicity of OTOF gene variation in patients with auditory neuropathy. Methods: Thirty-eight auditory neuropathy patients with OTOF gene variant were selected as the study subjects (23 males and 15 females, aged 0.3-25.9 years). Using whole-genome sequencing, whole exome sequencing or target region sequencing (Panel) combined with Sanger sequencing, 38 cases were found to carry more than two OTOF mutation sites. A total of 59 candidate variants were independently interpreted based on the 2015 ACMG/AMP guideline and 2018 HL-EP guideline. Compared with the judgment results in 2015 ACMG/AMP guideline, the variants interpreted as lower pathogenic classifications in the 2018 HL-EP guideline were defined as downgraded variants, and the variants regarded as higher pathogenic classifications were defined as upgraded variants. Statistical analysis was conducted using SPSS 20.0. Results: The concordance rate of variant classification between the guidelines was 72.9%(43/59). The 13.6%(8/59) of variants were upgraded and 13.6% (8/59) of variants downgraded in the classifications of the 2018 HL-EP guideline. A couple of rules saw significant differences between the guidelines (PVS1, PM3, PP2, PP3 and PP5). The distribution of pathogenicity of splicing mutation was statistically different (P=0.013). Conclusions: The 2018 HL-EP guideline is inconsistent with the 2015 ACMG/AMP guideline, when judging the pathogenicity of OTOF gene variants in patients with auditory neuropathy. Through the deletion and refinement of evidence and the breaking of solidification thinking, the 2018 HL-EP guideline makes the pathogenicity grading more traceable and improves the credibility.

[Research on the variation in distortion product otoacoustic emissions in patients with auditory neuropathy during the natural course of the disease].

Objective: The purpose of this study was to investigate the characteristics of distortion product otoacoustic emissions (DPOAE) in patients with auditory neuropathy (AN). The factors affecting DPOAE elicitation rate of each frequency, elicitation rate of each ear and change rate of first and last diagnosis in the natural course were analyzed. Methods: The sample was obtained from the Multicenter Study on Clinical Diagnosis and Intervention of AN (registration number: ChiCTR2100050125), and the diagnostic criteria for AN were based on the Chinese Clinical Practice Guidelines of Auditory Neuropathy (version 2022). Patients with bilateral AN who underwent 2 or more DPOAE tests were screened and divided into infant groups (≤3 years old) and non-infant groups (>3 years old) according to the age of detection, and the trend of DPOAE elicitation rate of each frequency, elicitation rate of each ear and change rate in the natural course of disease were analyzed, in order to explore the relevant influencing factors. Results: A total of 165 patients (330 ears) with AN were included in the study. The overall DPOAE elicitation rate per ear was 77.0%±29.4% at the initial diagnosis and 65.1%±35.2% at the final diagnosis, with a reduction observed in the elicitation rate of 171 ears (51.82%). In the infant group, there were 49 cases (98 ears), including 28 males and 21 females, whose found age ranged from 0 to 3 years old, with a median age of 0.7 years. DPOAE elicitation rate per ear was 57.9%±35.5% in the initial diagnosis, and 32.4%±32.1% in the final diagnosis, with a reduction observed in the elicitation rate of 69 ears (70.41%). In the non-infant group, there were 116 cases (232 ears), including 59 males and 57 females, ranging in found age from 3.9 to 40 years old, with a median age of 14 years old. DPOAE elicitation rate per ear was 84.6%±23.4% in the initial diagnosis, and 78.3%±27.1% in the final diagnosis, with a reduction observed in the elicitation rate of 102 ears (43.97%). Age was found to be correlated with DPOAE changes by multicategorical unordered logistic regression analysis (B=-0.224, OR=0.799, P<0.001). Conclusions: The elicitation rate of DPOAE in AN patients decreases or even disappears with increasing disease duration; The rate of DPOAE extraction is found to be lower in infant patients with auditory neuropathy (AN) compared to non-infant AN patients. Additionally, it is observed that the decrease in DPOAE extraction rate is more pronounced in infant AN patients as the disease progressed, as compared to non-infant AN patients. DPOAE and cochlear microphonic potentials should be fully combined for accurate diagnosis, and regular follow-up should be conducted to understand the natural course of the disease and give personalized guidance and assistance.

[Distribution characteristics and correlation analysis of GJB2 variation in patients with auditory neuropathy].

Objective:To elucidate the correlation between the GJB2 gene and auditory neuropathy, aiming to provide valuable insights for genetic counseling of affected individuals and their families. Methods:The general information, audiological data（including pure tone audiometry, distorted otoacoustic emission, auditory brainstem response, electrocochlography）, imaging data and genetic test data of 117 auditory neuropathy patients, and the patients with GJB2 gene mutation were screened out for the correlation analysis of auditory neuropathy. Results:Total of 16 patients were found to have GJB2 gene mutations, all of which were pathogenic or likely pathogenic.was Among them, one patient had compound heterozygous variants GJB2[c. 427C>T][c. 358_360del], exhibiting total deafness. One was GJB2[c. 299_300delAT][c. 35_36insG]compound heterozygous variants, the audiological findings were severe hearing loss.The remaining 14 patients with GJB2 gene variants exhibited typical auditory neuropathy. Conclusion:In this study, the relationship between GJB2 gene and auditory neuropathy was preliminarily analyzed,and explained the possible pathogenic mechanism of GJB2 gene variants that may be related to auditory neuropathy.

Cochlear implantation in children with auditory neuropathy spectrum disorder: an updated systematic review.

BACKGROUND: The goal of managing auditory neuropathy spectrum disorder (ANSD) is to restore the children's ability to discriminate auditory information. Children who are not making sufficient progress in speech comprehension, and speech and language development after receiving adequate auditory re/habilitation and/or acoustic amplification may be candidates for cochlear implantation (CI). Despite the growing number of published literature on CI outcomes in children with ANSD, the current evidence is primarily based on case reports or retrospective chart reviews some of which had a limited number of children. In addition, the outcomes of CI seem to vary between children with ANSD. Thus, compelling evidence is lacking. This updated systematic review evaluated the speech perception, language, and speech intelligibility outcomes of children with ANSD post-CI. METHODS: An online bibliographic search was conducted in PubMed, Scopus, Web of Science, and CENTRAL databases. We included both interventional and observational studies that assessed the outcomes of the CI in  children with ANSD. RESULTS: Thirty-three studies were included in this systematic review. Several tests were used to assess speech perception following CI in children with ANSD. The findings of this study revealed that  children with ANSD had mean Categories of Auditory Performance scores ranging from 4.3 to 7 post-operatively, this result was better than the pre-operative scores which ranged between 0.4 to 2.5. Likewise, the Infant-Toddler Meaningful Auditory Integration Scale, Phonetically Balanced Kindergarten, and multisyllabic lexical neighborhood test showed clinically relevant improvement after CI. The same findings were reported for language and speech intelligibility scores. One study investigated the quality of life/children satisfaction after CI and showed overall good satisfaction with the outcomes. CONCLUSIONS: The present systematic review suggests that CI is a feasible and effective hearing  rehabilitation modality for children with ANSD. REGISTRATION AND PROTOCOL: PROSPERO ID: CRD42021279140.

Auditory Neuropathy Spectrum Disorder Progressing with Motor and Sensory Neuropathy Caused by an ATP1A1 Variant.

We encountered a 27-year-old Japanese woman with sensorineural deafness progressing to motor and sensory neuropathy. At 16 years old, she had developed weakness in her lower extremities and hearing impairment, which gradually deteriorated. At 22 years old, combined audiological, electrophysiological, and radiological examination results were consistent with auditory neuropathy spectrum disorder (ANSD). Genetic analyses identified a previously reported missense variant in the ATP1A1 gene (NM_000701.8:c.1799C>G, p.Pro600Arg). Although sensorineural deafness has been reported as a clinical manifestation of ATP1A1-related disorders, our case suggested that ANSD may underlie the pathogenesis of deafness in ATP1A1-related disorders. This case report broadens the genotype-phenotype spectrum of ATP1A1-related disorders.

RNA base editing therapy cures hearing loss induced by OTOF gene mutation.

Otoferlin (OTOF) gene mutations represent the primary cause of hearing impairment and deafness in auditory neuropathy. The c.2485C>T (p. Q829X) mutation variant is responsible for approximately 3% of recessive prelingual deafness cases within the Spanish population. Previous studies have used two recombinant AAV vectors to overexpress OTOF, albeit with limited efficacy. In this study, we introduce an enhanced mini-dCas13X RNA base editor (emxABE) delivered via an AAV9 variant, achieving nearly 100% transfection efficiency in inner hair cells. This approach is aimed at treating OTOFQ829X, resulting in an approximately 80% adenosine-to-inosine conversion efficiency in humanized OtofQ829X/Q829X mice. Following a single scala media injection of emxABE targeting OTOFQ829X (emxABE-T) administered during the postnatal day 0-3 period in OtofQ829X/Q829X mice, we observed OTOF expression restoration in nearly 100% of inner hair cells. Moreover, auditory function was significantly improved, reaching similar levels as in wild-type mice. This enhancement persisted for at least 7 months. We also investigated P5-P7 and P30 OtofQ829X/Q829X mice, achieving auditory function restoration through round window injection of emxABE-T. These findings not only highlight an effective therapeutic strategy for potentially addressing OTOFQ829X-induced hearing loss but also underscore emxABE as a versatile toolkit for treating other monogenic diseases characterized by premature termination codons.

[The follow-up study on patients of children with auditory neuropathy].

Objective:To analyse the audiological characteristics of patients of children with auditory neuropathy（AN） for gaining a better understanding of the audiological characteristics prognosis of patients with AN. Methods:58 patients（108 ears） of children with AN were enrolled, all of whom had received further consultation within 10 years after the first consultation. Behavioral audiometry test, tympanogram test, distortion product otoacoustic emission（DPOAE）, auditory brainstem response（ABR）, cochlear microphonics（CM）, auditory steady-state response（ASSR） were performed on these patients. Results:①There were no significant changes in behavioral audiometry threshold between first and further consultation（P>0.05）；②Tympanograms were mostly of type A or As； ③The patients had worse DPOAE results in the further consultation, while the elicitation rate of other frequencies were higher except for the lower elicitation rate of 750 Hz and 1000 Hz；④There were 7 ears that had present ABR and CM in the first consultation, while three ears had present ABR and CM in the further consultation；⑤Except for 500 Hz, other frequency thresholds of ASSR in the further consultation were statistically significant compared with those in the first consultation（P<0.01）；⑥The threshold of behavioral audiometry at 4000 Hz was higher than that of ASSR, and there was no obvious correlation between the other frequencies（P>0.05）. Conclusion:There is a tendency of hearing deterioration in patients of children with AN. Patients with no DPOAE elicitation and no ABR elicitation or serious abnormalities need CM test to avoid misdiagnosis. The hearing status and speech communication ability of patients should be continuously monitored. Parents should pay attention to the changes in the behavioral ability of the children in daily life and make regular subsequent visits.

Results of cochlear implant surgery in patients with auditory neuropathy.

OBJECTIVES: The primary aim of this study was to analyze the benefit of cochlear implants for patients with auditory neuropathy. The secondary aim was to identify risk factors for auditory neuropathy. MATERIALS AND METHODS: Patients with cochlear implants (CIs) who were educated in hearing rehabilitation schools were included in the study. A total of 175 children were operated on for cochlear implantation between August 2019 and August 2021 in the department of otorhinolaryngology at different centers in Turkey, and while 16 (9.1%) of those patients had auditory neuropathy spectrum disorder (ANSD), 159 (90.9%) had sensorineural hearing loss (SNHL). Differences in auditory perception between the two groups were examined. Auditory perception tests were applied for these patients 6 months after CI surgery. The auditory perception performances of the patients were evaluated with the Evaluation of Auditory Responses to Speech (EARS) battery, including the Littlears, Lip, Bis4, Bis12, Cap, Sir, Mtp-3, Mtp-6, Mtp-12, Matrix A1, and Gasp tests. RESULTS: All patients had profound bilateral SNHL. Four auditory perception tests (Littlears, Bis-12, Sir, Matrix A1) showed similar results between patients with ANSD and SNHL, but seven auditory perception tests (Lip, Bis-4, Cap, Mtp-3, Mtp-6, Mtp-12, Gasp) showed significantly higher results among patients with SNHL. Hyperbilirubinemia, prematurity, consanguineous marriage, and family history of hearing loss were found to be common among patients with ANSD. CONCLUSIONS: ANSD patients who do not benefit from hearing aids benefit from CI surgery.

Gender differences in contralateral suppression of spontaneous otoacoustic emissions in individuals with auditory neuropathy spectrum disorders.

PURPOSE: The current study aims to evaluate gender variations in the efferent auditory system functioning in the ANSD population and compare them to normal hearing persons using contralateral suppression of spontaneous OAE (SOAEs). METHODS: For the current study, a total of 54 ears were considered prospectively. 27 ears with normal hearing (NH) sensitivity were in group I, while 27 ears with ANSD were in group II. All of the subjects had a regular audiological examination followed by synchronised SOAE recordings with and without broadband noise (in the contralateral ear) at 50 dB SPL and statistical analysis was carried out. RESULTS: Wilcoxon signed rank test revealed a significant decrease in SOAE amplitude with contralateral noise stimulation in NH, while no such trend was observed in ANSD. However, contralateral SOAE stimulation resulted in significant high-frequency shifts for both the ANSD and NH groups in the noise condition. In the comparison of gender effects on SOAE amplitude and frequency shifts using Mann-Whitney, no significant gender differences were seen. The lack of gender differences in SOAE suppression is explained based on global standing wave theory and local oscillator theory. CONCLUSIONS: Contralateral effect of noise on SOAE shows frequency shifts, but not amplitude shifts both of which are not affected by gender effects.

Auditory neuropathy: from etiology to management.

PURPOSE OF REVIEW: Auditory neuropathy is a disorder of auditory dysfunction characterized by the normal function of the outer hair cells and malfunction of the inner hair cells, synapses, postsynapses and/or auditory afferent nervous system. This review summarizes the process of discovery and naming of auditory neuropathy and describes the acquired, associated genetic disorders and management available. RECENT FINDINGS: In the last 40 years, auditory neuropathy has undergone a process of discovery, naming and progressive elucidation of its complex pathological mechanisms. Recent studies have revealed numerous acquired and inherited causative factors associated with auditory neuropathy. Studies have analyzed the pathogenic mechanisms of various genes and the outcomes of cochlear implantation. New therapeutic approaches, such as stem cell therapy and gene therapy are the future trends in the treatment of auditory neuropathy. SUMMARY: A comprehensive understanding of the pathogenic mechanisms is crucial in illustrating auditory neuropathy and assist in developing future management strategies.

[Objective Audiological Test Procedures: Indications and Differential Diagnostics]. / Objektive audiologische Messverfahren: Indikationen und Differenzialdiagnostik.

Diagnostics of hearing loss comprises subjective and objective methods and is successfully applied since many decades. This article introduces into the methods of impedance audiometry, otoacoustic emissions, auditory evoked potentials and electrically evoked potentials and describes the respective methodologies. Using an exemplary case, in this article we guide through all stages of objective audiological diagnostics and introduce the scientific and technical background, the application and evaluation of the findings of the objective test procedures. An application pathway for objective audiometric diagnostic tools is also described, including newborn hearing screening, differential diagnostics of hearing loss, auditory neuropathy, sudden sensorineural hearing loss, vestibular schwannoma and pediatrics patients. Finally, the application to patients with active middle-ear implants and cochlear implants is described.