Hearing Loss Of Unknown Origin Research Articles

Causes of hearing loss and implantation age in a cohort of Danish pediatric cochlear implant recipients.

Sensorineural hearing loss (SNHL) is the most common birth disorder. The cause of SNHL is heterogeneous and varies in different populations. Understanding the causes of a hearing loss (HL) predict the outcome of cochlear implantation and is of great importance in understanding the mechanism of the disease and in providing the best treatment. Undiagnosed and untreated HL has a profound effect on the acquisition of early communication skills, speech, language, academic, emotional, and psychosocial development in children. To determine the cause of HL and implantation age in pediatric cochlear implant (CI) users in a Danish population. Data of 100 children (54 females and 46 males), age 0-17 years, was analyzed. All of the children were implanted during 2020-2022. Hereditary HL was diagnosed in 44 cases (44%), with pathogenic variants in the SLC26A4 gene found in 14 cases (14%). Syndromic HL was diagnosed in 23 children (23%). Non-syndromic HL was diagnosed in 21 children (21%), where the most common genetic variation was found in the GJB2 gene. Acquired prenatal and postnatal sensory disorders TORCH risk factors were associated with HL in 25 cases (25%). Congenital CMV DNA was diagnosed in 23 samples (23%). The cause of the HL remained unknown for 31 (31%) children. In 70 (70%) of the participants the HL was diagnosed at time of newborn hearing screening (NHS). Twenty-three of the children were diagnosed with congenital severe to profound bilateral HL and were simultaneously implanted between 8 and 14 months (mean age 10.5 months). In the remaining 47 cases, the HL was progressive and the children were implanted when the HL reached the criteria for implantation. In the current study, the major causes of HL were alterations in the SLC26A4 gene: 13% with Pendred syndrome and 1% non-syndromic. Thirty-one (31%) had HL of unknown origin and almost half of these cases had inner ear malformations (n=16).

Etiological profile of hearing loss amongst Lithuanian pediatric cochlear implant users

IntroductionCongenital sensorineural hearing loss is a heterogeneous disorder; its etiological profile varies between populations. Pathogenic variants of GJB2 gene are the major cause of non-syndromic hearing loss. Congenital cytomegalovirus infection (cCMV) is the most important prenatal etiological factor causing hearing loss and other disorders. Perinatal events, syndromes, postnatal infections or traumas are less common. Causes of the remaining one third of hearing loss cases are unknown. ObjectivesTo determine the etiological profile of hearing loss in pediatric cochlear implant users in Lithuanian population. MethodsThe data of 122 children (70 male/52 female; aged 7.6 ± 3.3 years) cochlear implant users were analysed. Medical records of all children recruited in Santaros Clinics (Vilnius, Lithuania) were analysed to identify prenatal, perinatal, or postnatal risk factors based on the adapted list proposed by the Joint Committee of Infant Hearing. Genetic counselling and testing according to the scheme were performed to 101 children. DNA of 117 children was extracted from the DBS on Guthrie cards and CMV DNA detected using real time PCR. ResultsNon-syndromic hearing loss was diagnosed in 65 cases (53.3%), 58 of which were GJB2 gene-associated; syndromic hearing loss was diagnosed to 8 children (6.6%). Perinatal (prematurity, low birth weight, hypoxia, hyperbilirubinemia, sepsis, ototoxicity, and meningitis) and postnatal (meningitis) risk factors were associated with hearing loss in 16 (13.1%) and 4 (3.3%) study participants respectively. CMV DNA was detected in 12 samples (9.8%). The cause of hearing loss remained unknown only for 17 (13.9%) children. ConclusionsThe major cause of HL in the current study was GJB2 gene alterations. Only 14% of the cohort had congenital hearing loss of unknown origin.

Cochlear implant outcomes in the elderly: a uni- and multivariate analyses of prognostic factors.

To assess preoperative features that could predict the audiological outcome after cochlear implantation in the elderly, in terms of pure tone audiometry, speech audiometry, and speech perception performance. All available records of patients with cochlear implants aged 65 or more at the time of their implantation at our Institution were reviewed (50 patients, mean age 70.76 ± 4.03years), recording preoperative clinical features. Pure tone audiometry, speech audiometry, and speech perception performance 1year after cochlear implant activation and fitting were used as outcome measures. No statistically significant association emerged between clinical features and pure tone audiometry. On univariate analysis, progressive sensorineural hearing loss of unknown origin was associated with a better outcome in terms of speech audiometry and speech perception performance (p = 0.035 and p = 0.033, respectively). On multivariate analysis, progressive sensorineural hearing loss retained its independent prognostic significance in terms of speech perception performance (p = 0.042). The discriminatory power of a two-variable panel (age and etiology of hearing loss) featured an AUC (ROC) of 0.738 (an acceptable discriminatory power according to the Hosmer-Lemeshow scale). A progressive sensorineural hearing loss of unknown origin was associated with a better outcome in terms of speech perception in the elderly in our case study. Further features that can predict audiological outcome achievable with cochlear implants in the elderly are desirable to perform adequate counselling and rehabilitation programs.

Predictive Value of GJB2 Mutation Status for Hearing Outcomes of Pediatric Cochlear Implantation.

Objective To systematically review and quantify current evidence regarding the association of GJB2 mutation status with outcomes of pediatric cochlear implantation. Data Sources PubMed, Embase, and the Cochrane Library were searched for "GJB2,""pediatric hearing loss," and "cochlear implantation" and their synonyms, with no language restrictions, until December 2, 2015. Review Methods Studies were included that investigated the status of GJB2 mutation and its predictive value for outcomes of pediatric cochlear implantation. Speech recognition scores, Infant-Toddler Meaningful Auditory Integration Scale, Speech Intelligibility Rating, and Categorized Auditory Performance were pooled using weighted mean differences, and a 95% confidence interval. Results Eighteen studies met the inclusion criteria. The differences between GJB2-related deafness and non- GJB2-related deafness due to unidentified causes and other types of genetic deafness without additional disabilities were not statistically significant ( P = .15 and P = .30, respectively); however, the difference between GJB2-related deafness and acquired hearing loss due to environmental etiologies was statistically significant and favored GJB2-related deafness ( P = .03). Conclusion GJB2-related deafness leads to significantly better cochlear implantation outcomes when compared with acquired deafness caused by environmental etiologies. However, GJB2 mutation is not associated with a significantly better prognosis when compared with those whose deafness results from either nonsyndromic hearing loss of unknown origin or other types of genetic mutations in the absence of other neurologic deficits.

Speech and Language Delay: Hearing Loss of Unknown Origin or Manifestation of a Syndrome?

Speech and Language Delay: Hearing Loss of Unknown Origin or Manifestation of a Syndrome?

Hearing changes in the contralateral ear with juvenile unilateral profound hearing loss of unknown origin

Hearing changes in the contralateral ear with juvenile unilateral profound hearing loss of unknown origin

Hearing changes in the contralateral ear with juvenile unilateral profound hearing loss of unknown origin

Summary Objectives : Investigate contralateral hearing changes in patients with juvenile unilateral profound hearing loss (JUPHL) of unknown origin because patients with JUPHL have potentially bilateral hearing loss. Study design : A retrospective study. Setting : A tertiary referral center. Patients : Fifty patients with JUPHL of unknown origin included 42 unilaterally deaf patients and 8 patients with hearing loss over 70dB HL. The age of the patients was less than 15 years old at the first visit to our outpatient clinic. Patients with inner ear anomalies were excluded using CT images. Main outcome measures : The results of pure tone audiometry (PTA) were investigated. To obtain reliable PTA results, patients were over 6 years old. The following items were examined: level, fluctuation and worsening of hearing. Results : A hearing level over 30dB was observed at 20%, 4%, and 10% of patients in the low, middle and high frequencies, respectively. Hearing fluctuations were observed in 72%, 42% and 64% at the low, middle and high frequencies, respectively. Hearing worsening was observed in 8%, 4% and 4% at the low, middle and high frequencies, respectively. Conclusion : Seventy-two percent of patients with JUPHL had fluctuating hearing at low frequencies, and 8% of them had worsening hearing. These results imply that over 70% of patients with JUPHL may develop contralateral hearing loss and that we have to follow-up patients with unilateral juvenile profound hearing loss for a long time.

突発性難聴に対するステロイド２クール療法

Idiopathic sudden hearing loss is a cochlear type of hearing loss of unknown origin. Between 1996 and 2001, we treated 206 patients, 209 ears with sudden deafness. At our hospital, we have been applying high dose steroid therapy in such cases. In this retrospective study, we report the successful treatment of patients with sudden hearing loss following a second course of steroids. We divided patients into two groups: 46 patients, 47 ears receiving a second course therapy of steroids and 160 patients, 162 ears receiving a single course. An analysis of case report gave the following findings:1) There were no significant differences in age or gender distributions between two groups. However, sudden hearing loss in the second steroid therapy group was more severe than that in the single group.2) The second course of steroids caused liver function disorder, gastric colic, and elevated blood sugar, but these symptoms were reversible.3) Hearing prognosis in sudden deafness classified as Grade 4 at the initial examination was improved by a second course of steroid therapy.4) At the end of the first course of steroid therapy, 68 patients, 69 ears were diagnosed as showing no effects. In this group, 29 patients, 30 ears were treated by a second course of steroid therapy (group A) and 39 patients, 39 ears were treated without further steroid administration (group B). The rate of marked and fair improvement in group A was significantly higher than that of group B.These findings indicate that a second course of steroid therapy has a significant beneficial effect on hearing level improvement. Finally, a carefully planned second course of steroid therapy appears to be a safe and effective for inveterate sudden hearing loss.

Clinical features of bilateral progressive hearing loss associated with myeloperoxidase-antineutrophil cytoplasmic antibody.

In this study, we analyzed the clinical features, diagnostic criteria, treatment, and outcome of atypical bilateral progressive hearing loss associated with myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA). The evaluation was made by audiogram and laboratory data in 6 cases treated at Hokkaido University Hospital. We measured MPO-ANCA by enzyme-linked immunosorbent assay; the result was positive in all cases. The hearing loss developed bilaterally and progressed to total deafness within several weeks. The onset of hearing loss was not simultaneous in the 2 ears. Methylprednisolone pulse therapy was effective in 9 ears. Three ears showed no improvement; 2 of the 3 ears had already exhibited total deafness at the first visit. After the treatment, the titer of MPO-ANCA decreased in all patients. The level of MPO-ANCA should be tested in patients with bilateral progressive hearing loss of unknown origin and can be used as a marker of the disease's activity.

Advances in the Hearing Sciences: Current Research and Clinical Applications

Advances in the Hearing Sciences: Current Research and Clinical Applications

Hearing evaluation with distortion-product otoacoustic emissions in young patients undergoing haemodialysis.

Sensorineural hearing loss is frequently reported in young patients with chronic renal failure having haemodialysis. The effect of a single session of haemodialysis on hearing acuity was assessed prospectively in nine children with end-stage renal disease using pure-tone audiometry (PTA) and distortion-product otoacoustic emissions (DPOAEs). Results were compared with those obtained from nine audiologically normal healthy children also tested with PTA and DPOAEs twice during a 4-h interval. Sensorineural hearing loss of unknown aetiology was found in 55.5% of renal patients, mainly in the higher frequencies. Patients on HD had mean PTA thresholds significantly poorer than those of the control group in the frequency range 1000-12 000Hz (P < 0.05). Their mean DPOAE amplitudes were significantly lower in all frequencies > 1184 Hz (P < 0.05). Furthermore, patients' ears with normal PTA thresholds between 250 and 4000 Hz also had decreased DPOAE amplitudes. No significant changes in PTA thresholds or DPOAE amplitudes were encountered in renal patients before and after a HD session (P > 0.05). Changes in PTA thresholds or DPOAE amplitudes were not significantly different than those in the control group (P > 0.05). In conclusion, sensorineural hearing loss of unknown origin, especially in high frequencies, is frequent in young renal patients under HD and single HD sessions do not seem to alter the hearing acuity of these patients. DPOAEs seem to be more sensitive to incipient cochlear damage than behaviour thresholds in monitoring renal patients.

Mutations in the connexin26/GJB2 gene are the most common event in non-syndromic hearing loss among the German population

Congenital sensorineural hearing loss affects approximately 1/1,000 live births. Mutations in the gene encoding connexin26 (GJB2) have been described as a major cause of genetic nonsyndromic hearing impairment. Additionally, another gap junction gene, connexin30 (GJB6), was found to be responsible for hereditary hearing loss. We have studied 134 patients with severe to profound hearing loss or deafness and 13 patients with mild to moderate nonsyndromic sensorineural hearing loss in order to evaluate the prevalence of connexin26 and connexin30 mutations in Germany. Mutations in the connexin26 gene were found in 30 patients (22%) with profound to severe hearing impairment whereas only one novel single nucleotide polymorphism (396G-->A) in the connexin30 gene was detected. Among the 13 patients with mild to moderate hearing loss neither mutations in the connexin26 nor in the connexin30 gene could be detected. These results demonstrate that mutations in the connexin26 gene are also a frequent cause of hereditary non-syndromic hearing loss in Germany. Therefore a screening of mutations in the connexin26 gene should be performed in every case of non-syndromic hearing loss of unknown origin.

Presence of Tinnitus Indicated by Variable Spontaneous Otoacoustic Emissions

Spontaneous otoacoustic emissions (SOAE) have been widely studied in normal subjects, and there is evidence of their high frequency stability in repeated recordings. A study to determine the frequency stability of SOAE in 53 of 100 consecutive patients, who presented with tinnitus and in whom SOAE were recordable, was undertaken. Patients were divided into five aetiologically homogeneous subgroups: (i) those with normal hearing and no identified pathology, (ii) those with sensorineural hearing loss of unknown origin, (iii) those with normal hearing, but complaining of tinnitus related to head injury, (iv) those with endolymphatic hydrops, and (v) those with noise exposure. The control group consisted of 20 subjects, selected on the basis of recordable SOAE from 38 volunteers with normal hearing and no tinnitus. The prevalence of SOAE and their inter-session frequency stability (reproducibility and relative frequency shift) were analysed. In contrast to the controls, the tinnitus group had significantly increased frequency variability of SOAE (lower reproducibility and increased relative frequency shift). The prevalence of subjects with SOAE was not notably different between the controls and subjects with tinnitus, if the tinnitus group was considered in toto, but a striking 100% prevalence of bilaterally present SOAE was observed in the tinnitus subgroup with head injury.

機能性難聴における持続音と断続音の域値差

A simple yet reliable easy screening method for functional hearing loss was developed using an air conduction pure-tone audiometer.We performed pure-tone audiometry in 440 ears from 220 patients (101 males, 119 females) using 7 continuous and 7 pulse pure tones at 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz and 8000 Hz. The hearing thresholds measured by continuous tones were compared with those measured by pulse tones at each frequency, and the number of frequencies which showed a 10 dB or greater threshold improvement or deterioration were counted.Of the 440 ears, 130 ears were diagnosed with sensorineural hearing loss of unknown origin, 51 ears with functional hearing loss, 48 ears with normal hearing, 39 ears with congenital sensorineural hearing loss, 29 ears with presbycusis and 22 ears with occupational noise deafness or others. A comparison of the hearing thresholds in the 440 ears revealed greater than 1 out of 7 frequencies threshold improvements in 48 ears (10.9%), greater than 1 out of 7 frequency deterioration in 30 ears (6.8%), and only one or no frequency threshold differences in 362 ears (82.3%). In the 48 ears with improved thresholds, 38 ears (79.2%) were diagnosed with functional hearing loss. Moreover, 27 ears (6.1%) out of the 440 ears showed over 4 frequencies threshold improvements, and all of these ears were diagnosed with functional hearing loss.These results suggest that this novel method, comparing the thresholds measured by continuous versus pulse tones, was useful for the simple screening of functional hearing loss. If a threshold improvement using a continuous tone is observed in more than 1 frequency, then functional hearing loss should be suspected, and threshold improvements in more than 4 frequencies are even more likely to indicate functional hearing loss. For further accurate diagnosis, Bekesy audiometry and auditory brain stem evoked responses are useful.

No evidence of hearing loss due to fetal acoustic stimulation test : Arulkumaran S.; Skurr B.; Tong H.; Kek L.P.; Yeoh K.H.; Ratnam S.S.OBSTET. GYNECOL. (1991) 78/2 (283–285)

The fetal acoustic stimulation test is used increasingly for fetal assessment. To evaluate the possibility of acoustic trauma, 465 children who had been exposed to vibroacoustic stimulation in utero were screened at 4 years of age for high-frequency hearing loss. A hand-held audiometer with test tones at 25 dB for 1000 and 4000 Hz was used because responses at this level indicate hearing within normal limits for middle and high frequencies. Thirty-one children failed the test. Failure to respond was followed by inspection of the ear canal for wax, tympanometry, and reflex measurement to assess the tympanic membrane, middle ear, and eustachian tube. Hearing was retested across the full frequency range using conventional audiometric technique, and referral for otolaryngologic examination and treatment was made if necessary. The causes of hearing loss were impacted wax in 12, current or recent upper respiratory tract infection with eustachian tube dysfunction and middle ear effusion in 15, and unresolved middle ear effusion after treatment with antibiotics for otitis media in two. Profound bilateral sensorineural hearing loss of unknown origin was found in one and slight bilateral gently sloping hearing loss in another. Retesting of all children with conductive hearing loss indicated that hearing had returned to normal after treatment. None of the children showed evidence of hearing loss.

内耳疾患と免疫異常

Three studies were undertaken in order to clarify the incidence of autoimmunity in inner ear diseases.In the first study, the records of 255 patients with Meniere's disease and 127 patients with bilateral sensorineural hearing loss of unknown origin (SNHL) were examined retrospectively for the presence of autoimmune disease. Autoimmune diseases of various types were found in 4.7% of those with Meniere's cases and in 0.8% of those with SNHL.In the second study, 44 patients with unilateral Meniere's disease (unilateral patients), 51 with Meniere's disease with bilateral fluctuant hearing loss (bilateral patients), and 37 SNHL patients were tested for the following : ESR and CRP levels, immunoglobulin levels (IgG, IgM, IgA), complement levels (C3, C3, CH50), and autoantibody levels (rheumatoid factor, anti-DNA antibodies, and antinuclear antibodies).A significantly higher incidence of severe immunologic abnormalities was found in bilateral patients than unilateral or SNHL patients.In the third study, the results of the second study were correlated with inner ear function (hearing levels and caloric test results in Meniere's disease patients, and hearing levels in SN HL patients). Bilateral patients with severe immunologic abnormalities had poorer inner ear function in both ears than did patients with no or slight immunologic abnormalities. No relationship was observed between immunologic abnormality and inner ear function in unilateral Meniere's disease or SNHL.The results of the above investigations indicate the likelihood of autoimmune involvement in certain cases of Meniere's disease with bilateral fluctuant hearing loss, and suggest that Meniere's patients should be examined for immunologic abnormalities.

Bilateral sudden deafness and acute acquired toxoplasmosis

An 18-year-old woman, while suffering from acute acquired toxoplasmosis, experienced sudden deafness and a total loss of vestibular function first in the right ear and three months later also in the left. Following treatment with sulphadiazine and pyrimethamine, hearing was retrieved to such a degree that the patient was enabled to communicate by means of a body-worn hearing aid and lip-reading. Taking the differential diagnostic possibilities into account, we believe that toxoplasmosis was the cause of the severe hearing loss. Since effective treatment seems to be available, we recommend that patients with acute bilateral sensorineural hearing loss of unknown origin are examined for acute toxoplasmosis with a view to instituting chemotherapy.

The Clinical Application of Acoustic Distortion Products

Otoacoustic emissions provide an objective measure of hair-cell function that is independent of retrocochlear activity. Because of their frequency specificity, distortion-product emissions have great potential for clinical use. The present report describes the results of initial studies in patients with known cochlear or retrocochlear disease, diagnosed with standard otologic and audiologic tests. The cochlear group consisted of those diagnosed with noise-induced hearing loss, Meniere's disease, or hereditary hearing loss, whereas patients with acoustic neuroma comprised a retrocochlear group. A final group consisted of patients with sudden sensorineural hearing loss of unknown origin. Detailed distortion-product emission testing included the computer-controlled acquisition of "audiograms" and response/growth functions. The outcomes of these studies demonstrated that distortion-product emissions provide a noninvasive, frequency-specific test of sensory-cell function that objectively depicts the boundary between normal and abnormal hearing. These emissions were also able to effectively track dynamic changes in progressive disease processes. Finally, as a screening tool, acoustic distortion products provide an objective means of assessing cochlear status in infants and young children and in adults at risk for hearing loss. Because acoustic distortion products accurately measure the sensory component of a sensorineural hearing loss, distortion-product testing may play an important role in the diagnosis and treatment of cochlear dysfunction.

Genetic counselling for isolated hearing loss.

An investigation into the causes of sensorineural hearing loss in young children has been used as a basis for determining risk factors for parents of children with a hearing loss of unknown origin having a further affected child and for the defect to be passed on to a subsequent generation. The degree of hearing loss likely to be found if further children are affected, is examined.

Hearing loss due to mumps.

The possibility of mumps was considered in 33 children with profound unilateral sensorineural hearing loss of unknown origin. Fifteen gave a history of mumps, of whom 12 contracted the infection between the last normal and first abnormal hearing tests. Hearing should be tested after mumps infection.