Hearing Loss Of Unknown Etiology Research Articles

Clinical Manifestation of Sensorineural Hearing Loss as an Extraintestinal Complication of Inflammatory Bowel Disease

AbstractInflammatory bowel disease (IBD) is an autoimmune condition often accompanied by extraintestinal manifestations including arthritis. However, hearing loss as an extraintestinal manifestation of IBD is rarely reported. This study aimed to investigate the clinical characteristics of sensorineural hearing loss associated with IBD. This study included patients with IBD and hearing loss who were registered between October 2005 and September 2022. The patients were diagnosed with ulcerative colitis (UC) or Crohn's disease (CD) by gastroenterologists in addition to sensorineural hearing loss of unknown etiology confirmed by otolaryngologists. Overall, 32 patients aged 10 to 78 years were included, consisting of 9 women, 18 patients with UC, and 14 patients with CD. Hearing loss associated with IBD was more common among men, with a median onset age of 56 years for UC and 33 years for CD. Two patients reported hearing loss in both ears before IBD onset, whereas 38 ears in 30 patients presented hearing loss after IBD onset. Various types of hearing loss were observed in the 42 affected ears. Further, hearing loss typically developed within 10 years of IBD diagnosis in approximately 63% of cases, with a median interval of 9 years among the 32 cases. In some cases, azathioprine and infliximab, therapeutic agents for IBD, were suspected to have contributed to the hearing loss. No other IBD medications were suspected to contribute to the hearing loss in any patient. The pathogenesis of hearing loss in IBD remains unclear; further large-scale investigations are warranted to elucidate the relationship between IBD and sensorineural hearing loss and to better understand the underlying pathophysiology.

Loss of the chromatin remodeler CHD7 impacts glial cells and myelination in the mouse cochlear spiral ganglion

CHARGE syndrome is a multiple anomaly developmental disorder characterized by a variety of sensory deficits, including sensorineural hearing loss of unknown etiology. Most cases of CHARGE are caused by heterozygous pathogenic variants in CHD7, the gene encoding Chromodomain DNA-binding Protein 7 (CHD7), a chromatin remodeler important for the development of neurons and glial cells. Previous studies in the Chd7Gt/+ mouse model of CHARGE syndrome showed substantial neuron loss in the early stages of the developing inner ear that are compensated for by mid-gestation. In this study, we sought to determine if early developmental delays caused by Chd7 haploinsufficiency affect neurons, glial cells, and inner hair cell innervation in the mature cochlea. Analysis of auditory brainstem response recordings in Chd7Gt/+ adult animals showed elevated thresholds at 4 kHz and 16 kHz, but no differences in ABR Wave I peak latency or amplitude compared to wild type controls. Proportions of neurons in the Chd7Gt/+ adult spiral ganglion and densities of nerve projections from the spiral ganglion to the organ of Corti were not significantly different from wild type controls. Inner hair cell synapse formation also appeared unaffected in mature Chd7Gt/+ cochleae. However, histological analysis of adult Chd7Gt/+ cochleae revealed diminished satellite glial cells and hypermyelinated Type I spiral ganglion axons. We characterized the expression of CHD7 in developing inner ear glia and found CHD7 to be expressed during a tight window of inner ear development at the Schwann cell precursor stage at E9.5. While cochlear neurons appear to differentiate normally in the setting of Chd7 haploinsufficiency, our results suggest an important role for CHD7 in glial cells in the inner ear. This study highlights the dynamic nature of CHD7 activity during inner ear development in mice and contributes to understanding CHARGE syndrome pathology.

Sociodemographic and hearing profile of a population with sensorineural hearing loss in Chile

Background. Evidence-based information on genetic sensorineural hearing loss in Latin America is limited, hindering the advancement of related clinical practice and the development of relevant healthcare policies in the field. This study describes sociodemographic and clinical characteristics of a group of Chilean participants with congenital, childhood, progressive or late-onset sensorineural hearing loss of unknown etiology; all non-genetic causes of hearing loss were excluded. Methods. A quantitative study, with a non-experimental, observational, cross-sectional design and a descriptive scope. From 978 patients diagnosed with SNHL, 286 subjects fulfilled the inclusion criteria, and 138 patients accepted to participate. Results. The most frequent audiological-profile was symmetrical-bilateral-profound-SNHL with a sloping pattern. The median age at audiological diagnosis was 24.5 months (IQR:12-53) and at first-time Hearing-Assistive-Device-use (HAD-use) was 30 months (IQR:13-69). 71% of HAD were financed by public resources. Conclusion. The age at audiological diagnosis in SNHL of suspected genetic causes is still far from international standards. These results are valuable for public health research and policy development, not only for the Chilean population, but also for other Hispanic communities and other middle-high income countries.

A High Risk of Missing Congenital Cytomegalovirus-Associated Hearing Loss through Newborn Hearing Screening in Japan.

It remains unclear to what extent newborn hearing screening (NHS) detects congenital cytomegalovirus (cCMV)-associated sensorineural hearing loss (SNHL) in Japan. This study aimed to clarify the NHS results and audiological characteristics of patients with cCMV-associated SNHL. A total of 541 individuals with unilateral or bilateral hearing loss of unknown etiology were examined for cCMV infection. cCMV infection was defined by the presence of CMV DNA in the dried umbilical cord detected using real-time quantitative PCR. NHS results and audiological data were retrospectively obtained from medical records. Forty-four cases (8.1%) were positive for cCMV infection. Of them, 33 cases underwent NHS and 13 cases (39.4%) passed NHS bilaterally. The pure-tone audiograms of 21 patients were obtained. There were seven cases of unilateral SNHL, five cases of asymmetric bilateral SNHL, and nine cases of symmetric bilateral SNHL. cCMV-related hearing loss is highly heterogeneous, and there is a high risk of missing this condition through NHS.

Hearing Status of Children and Adolescents With Familial Adenomatous Polyposis.

Chemopreventative therapeutics may be helpful in familial adenomatous polyposis (FAP) management; however, prospective chemopreventative studies are complicated by potential ototoxicity and pre-existing hearing loss. The aim of this study was to establish and compare baseline hearing status of children and adolescents with FAP and their unaffected siblings. Twenty FAP pediatric patients with documented mutation of the adenomatous polyposis coli (APC) gene and nine unaffected sibling controls underwent baseline hearing evaluation, including audiometry, speech perception testing, and middle and inner ear physiologic measures. Results of the FAP cohort were compared to the unaffected sibling cohort. Two (5%) children with FAP presented with baseline hearing loss of unknown etiology, likely unrelated to their FAP diagnosis. No significant differences were found in any of the hearing measures between groups. Mutation of the APC gene is not necessarily indicative of higher risk for baseline hearing loss in the pediatric population.

Is There an Association between the Anteroinferior Cerebellar Artery Vascular Loop and Asymmetrical Sensorineural Hearing Loss?

Abstract Background: Asymmetrical sensorineural hearing loss is usually idiopathic. Vascular loops are commonly implicated in compression disorders involving lower cranial nerves, which can be relieved on surgical decompression. However, the cause–effect relationship between vestibulocochlear symptoms and vascular loops is still controversial. Objective: The objective of this study is to look for an association between the presence of anteroinferior cerebellar artery (AICA) loops and asymmetrical sensorineural hearing loss of unknown etiology. Methods: Twenty-four patients with complaints of asymmetrical hearing loss of no discernible cause underwent a magnetic resonance imaging of the brain between August 2015 and August 2017. The AICA loops were graded using two classifications, namely Chavda classification and a grading system proposed by Adam Gorrie et al. (second classification). The vascular loops were correlated with the presence of hearing loss, tinnitus, and vertigo. Results: Hearing loss did not correlate significantly with the vascular loops on grading with either Chavda or the second classification. The presence of tinnitus or vertigo too did not correlate significantly with the grading of vascular loops. The caliber of AICA too did not correlate significantly with hearing loss. Conclusion: Vascular loops do not appear to be associated with asymmetrical hearing loss and other cochleovestibular symptoms.

Анализ мутационного спектра гена SLC26A4 и его вклада в этиологию наследуемой потери слуха у коренного населения Южной Сибири

Мутации в гене SLC26A4 являются частой причиной потери слуха во многих регионах мира. В работе приводятся результаты молекулярно-генетического анализа (с использованием секвенирования по Сэнгеру) последовательности гена SLC26A4, впервые проведенного в выборке пациентов с потерей слуха неустановленной этиологии (n=232) из Республик Тыва и Алтай. Установлены контрастные различия патогенетического вклада мутаций в гене SLC26A4 в этиологию нарушения слуха у коренных жителей этих географически близких регионов: 28,2% - для тувинцев и 4,3% - для алтайцев. Выявлены как уже известные, так и новые патогенные варианты, а также широкий спектр полиморфных вариантов гена SLC26A4. Mutations in the SLC26A4 gene are a common cause of hearing loss in many regions of the world. This paper presents the results of molecular genetic analysis (by Sanger sequencing) of the SLC26A4 sequence, first performed in the sample of patients with hearing loss of unknown etiology (n=232) from the Tyva Republic and the Altai Republic. Contrast differences of the pathogenic contribution of SLC26A4 mutations to the etiology of hearing impairment were revealed in the indigenous peoples of these geographically close regions: 28.2% for Tuvinians and 4.3% for Altaians. Both known and novel pathogenic variants as well as a wide range of polymorphic variants were found in the SLC26A4 gene sequence.

Functional Loss After Meningitis-Evaluation of Vestibular Function in Patients With Postmeningitic Hearing Loss.

Introduction: The inner ear vestibular system is essential to balance function. Although hearing loss is well-described and quite common following meningitis, the literature evaluating vestibular function following meningitis is very limited. In particular, information on results of contemporary vestibular function tests, e.g., the video head impulse test (VHIT), is scarce. Using contemporary vestibular function tests, this study examines the vestibular function of patients with profound hearing loss (HL) after meningitis.Methods: Review of the literature and retrospective controlled study.Patients: Twenty-one consecutive patients with profound HL after meningitis (cochlear implant candidates) matched with 20 patients with profound HL of unknown etiology and examined during the period 2013–2018.Outcome Measure: Vestibular function loss, as evaluated with VHIT vestibulo-ocular reflex (VOR) gain, eye movement saccades, and cervical vestibular-evoked myogenic potentials (cVEMPs). The results of these tests were correlated to inner ear imaging findings (MRI/CT) and the level of hearing loss.Results: Mean VHIT gain was 0.48 in the meningitis group compared to 0.86 in the control group (p < 0.01). Saccades were present in 21 ears (62%) in the meningitis group compared to six ears (15%) among the controls (p < 0.01). cVEMP responses were present on five ears (18%) in the meningitis group and 25 ears (66%) in the control group (p < 0.01).Discussion: Postmeningitic hearing loss is associated with poor vestibular function, as evaluated by VHIT, saccades, and cVEMP. Loss of vestibular function correlates with the degree of hearing loss and inner ear imaging findings, although not in all cases. Vestibular function should be examined in patients surviving meningitis with hearing loss in order to individualize rehabilitation and improve balance outcome.

Etiology of newborn hearing impairment in Guangdong province: 10-year experience with screening, diagnosis, and follow-up.

Hearing impairment is one of the most common birth defects in children. Universal newborn hearing screenings have been performed for 19years in Guangdong province, China. Ascreening/diagnosis/intervention system has gradually been put in place. Over the past 10years, a relatively complete data management system had been established. In the present study, an etiological analysis of newborn cases that failed the initial and follow-up screenings was performed. The nature and degree of hearing impairment in newborns were confirmed by a set of procedures performed at the time ofinitial hearing screening, rescreening and final hearing diagnosis. Then, multiple examinations were performed to explore the associated etiology. Over a period of 10years, 720 children were diagnosed with newborn hearing loss. Among these children, 445 (61.81%) children had a clearly identified cause, which included genetic factor(s) (30.56%), secretory otitis media (13.30%), maternal rubella virus infection during pregnancy (5.83%), inner ear malformations (4.86%), maternal human cytomegalovirus infection during pregnancy (2.92%), malformation of the middle ear ossicular chain (2.50%) and auditory neuropathy (1.81%). In addition, 275 cases of sensorineural hearing loss of unknown etiology accounted for 38.19% of the children surveyed. Long-term follow-up is needed to detect delayed hearing impairment and auditory development in children. The need for long-term follow-up should be taken into account when designing an intervention strategy. Furthermore, the use of the deafness gene chip should further elucidate the etiology of neonatal hearing impairment.

Hybrid cochlear implantation: quality of life, quality of hearing, and working performance compared to patients with conventional unilateral or bilateral cochlear implantation.

The objective of the present study is to evaluate the effect of hybrid cochlear implantation (hCI) on quality of life (QoL), quality of hearing (QoH), and working performance in adult patients, and to compare the long-term results of patients with hCI to those of patients with conventional unilateral cochlear implantation (CI), bilateral CI, and single-sided deafness (SSD) with CI. Sound localization accuracy and speech-in-noise test were also compared between these groups. Eight patients with high-frequency sensorineural hearing loss of unknown etiology were selected in the study. Patients with hCI had better long-term speech perception in noise than uni- or bilateral CI patients, but the difference was not statistically significant. The sound localization accuracy was equal in the hCI, bilateral CI, and SSD patients. QoH was statistically significantly better in bilateral CI patients than in the others. In hCI patients, residual hearing was preserved in all patients after the surgery. During the 3.6-year follow-up, the mean hearing threshold at 125-500Hz decreased on average by 15dB HL in the implanted ear. QoL and working performance improved significantly in all CI patients. Hearing outcomes with hCI are comparable to the results of bilateral CI or CI with SSD, but hearing in noise and sound localization are statistically significantly better than with unilateral CI. Interestingly, the impact of CI on QoL, QoH, and working performance was similar in all groups.

Endoscopic middle ear exploration in pediatric patients with conductive hearing loss

ObjectiveTo describe our indications, findings, and outcomes for transcanal endoscopic middle ear exploration in pediatric patients with conductive hearing loss of unknown etiology, without effusions. MethodsProspective case series for all pediatric patients undergoing totally endoscopic transcanal middle ear exploration between April 2012 and October 2015 at a pediatric tertiary care referral hospital. Demographic data, operative findings, and hearing results were reviewed. Results21 cases were performed in 20 ears (1 revision). Average age at surgery was 7.98 years and average follow up was 2.1 years. Middle ear pathology identified on CT imaging was confirmed in 55% of cases while identified in 45% of cases where pre-operative imaging was non-diagnostic. 6/20 patients (30%) had an ossicular deformity. 8/20(40%) had bony ossicular fixation. 5/20(25%) had ossicular discontinuity. 2/20(10%) had facial nerve dehiscence impinging on the stapes. 15% had adhesive myringosclerosis or severe granulation causing hearing loss. Prosthetic ossiculoplasty was done in 7/21 (33.3%) of the cases, with 1 TORP, 3 PORPs, and 3 IS joint replacements. Imaging was predictive of intra-operative findings in 13/20 cases (55%). Trainees assisted in 16/21(76%) of cases. The average improvement of PTA was 11.65 dB (range −10 to 36.25), and the average ABG improved 10.19 (range −11.25 to 28.75). There were no perioperative complications or adverse events. ConclusionsThe endoscopic transcanal approach for middle ear exploration offers excellent visualization and is one of the best applications for the endoscopes in pediatric otology cases. This is particularly helpful for “unexplained” conductive hearing loss where ossicular deformity/fixation/discontinuity is suspected. The etiology of the conductive hearing loss was definitively found in 100% of cases, and can be repaired in the same sitting when applicable.

Audio profiles in mitochondrial deafness m.1555A>G and m.3243A>G show distinct differences.

BackgroundHearing loss is one of the most common symptoms of mitochondrial disorders. However, audiological phenotypes associated with different molecular defects in mtDNA are not yet well characterized.Material/MethodsA large cohort of 1499 nonconsanguineous patients aged 5–40 years with hearing loss of unknown etiology was screened for mutations in mtDNA. For further analysis, patients harboring m.1555A>G and m.3243A>G were selected.Hearing status of the patients was assessed by pure tone audiometry. Patterns of audiograms (hearing threshold levels at each examined frequency) were statistically compared among the carriers of the m.1555A>G and the m.3243A>G mutations.ResultsWe identified 20 patients positive for m.1555A>G mutation and 16 patients positive for m.3243A>G change. The frequency of the above transitions was calculated in our cohort as 1.33% and 1.06%, respectively. Seventeen affected family members carrying the mutations were included into the study.Typical shape of the audiograms in patients with m.1555A>G mutation presented a ski-slope pattern, whereas the audiometric curves among the m.3243A>G individuals had a pantonal shape (a flat curve) with slight downward sloping at the higher frequencies. The differences were statistically significant.The onset of hearing loss was noted earlier among m.1555A>G than m.3243A>G patients (12.5 and 26 years, respectively). Aminoglycoside administration was declared in both groups in 11 and 4 cases respectively, and caused abrupt hearing deterioration in all cases.ConclusionsA pattern of audiogram in patients with mitochondrial deafness may suggest a localization of mtDNA mutation. The pathogenesis of the audiometric differences needs further study.

Diagnostic yield of computed tomography scan for pediatric hearing loss: a systematic review.

Computed tomography (CT) has been used in the assessment of pediatric hearing loss, but concern regarding radiation risk and increased utilization of magnetic resonance imaging (MRI) have prompted us toward a more quantitative and sophisticated understanding of CT's potential diagnostic yield. To perform a systematic review to analyze the diagnostic yield of CT for pediatric hearing loss, including subgroup evaluation according to impairment severity and laterality, as well as the specific findings of enlarged vestibular aqueduct and narrow cochlear nerve canal. PubMed, EMBASE, and the Cochrane Library were assessed from the date of their inception to December 2013. In addition, manual searches of bibliographies were performed and topic experts were contacted. Data from studies describing the use of CT in the diagnostic evaluation of pediatric patients with hearing loss of unknown etiology were evaluated, according to a priori inclusion/exclusion criteria. Two independent evaluators corroborated the extracted data. Heterogeneity was evaluated according to the I(2) statistic. In 50 criteria-meeting studies, the overall diagnostic yield of CT ranged from 7% to 74%, with the strongest and aggregate data demonstrating a point estimate of 30%. This estimate corresponded to a number needed to image of 4 (range, 2-15). The most commonly identified findings were enlarged vestibular aqueduct and cochlear anomalies. The largest studies showed a 4% to 7% yield for narrow cochlear nerve canal. These data, along with similar analyses of radiation risk and risks/benefits of sedated MRI, may be used to help guide the choice of diagnostic imaging.

Non-invasive methods for diagnosing diseases of the ear: Wideband acoustic immittance and umbo velocity

Measurements of ossicular motion using laser Doppler vibrometry (LDV) in patients with various ear diseases, along with fresh cadaveric experiments, have increased our understanding of how sound is transduced to the cochlea and how this transduction is modified by various conductive pathologies. These studies have dispelled some misguided beliefs, changed clinical treatments, and shown the potential of LDV as a diagnostic. LDV, however, has substantial limitations as a clinical tool. For patients with conductive hearing loss of unknown etiology (where general otologic exam and conventional tympanometry are not diagnostic), another non-invasive measurement, wideband acoustic immittance (WAI, directly related to power reflectance), in conjunction with audiometric measurements, can differentiate between ossicular fixation, ossicular discontinuity and superior canal dehiscence (SCD). Furthermore, WAI measurements show a common pattern in power reflectance in patients with SCD, with or without a conductive hearing loss. An algorithm to identify this pattern in power reflectance suggests that WAI may be a simple, inexpensive screening tool for SCD. Evidence will be presented from our studies on patients with various otologic diseases, as well as from fresh cadaveric preparations simulating various diseases. Power reflectance can assist in treatment decisions and prevent unnecessary and inappropriate treatments and surgeries.

Is Virtual Endoscopy of the Middle Ear Useful?

Virtual endoscopy is a relatively new imaging technology in otology, and therefore data on its efficacy in clinical situations are limited. We conducted a prospective study to evaluate the clinical relevance of radiologic diagnoses based on virtual endoscopy of the middle ear. Our patient population was made up of 30 adults who were scheduled to undergo surgery to correct conductive hearing loss of unknown etiology. Virtual endoscopy was performed on three-dimensional images that were constructed from images obtained with conventional two-dimensional computed tomography (CT). Findings on virtual endoscopy were then compared with the subsequent surgical findings. Virtual endoscopy suggested a middle ear pathology in 19 patients and a normal middle ear in 11 patients. Postoperatively, we found that the virtual diagnoses correlated moderately well with the surgical findings in the group of patients with predicted pathology; 13 of these 19 patients were found to have middle ear problems such as ossicular chain anomalies, otosclerosis, and cholesteatoma (positive predictive value: 68%). However, among the 11 patients whose middle ear structures were radiologically predicted to be normal, only 2 had negative middle ear findings on surgical exploration; of the remaining 9 patients, 8 had otosclerosis and 1 had malleus fixation (negative predictive value: 18%). Thus, the sensitivity and specificity of virtual endoscopy were 59 and 25%, respectively. Virtual endoscopy provides images from a surgeon's perspective, and so it has the potential to be useful in the preoperative evaluation of the middle ear cavity. With ongoing advancements in computer systems and imaging techniques, the cost, reliability, and efficacy of virtual endoscopy may improve. However, further clinical validation and cost-benefit analysis are required before we can determine if it has any additional advantages over conventional two-dimensional CT.

遅発性内リンパ水腫について―ことにメニエール病との比較において―

Delayed endolymphatic hydrops (DEH) is a Meniere’s syndrome that typically occurs in patients suffering from longstanding unilateral profound inner-ear hearing loss. Approximately 55 to 65% of the hearing loss preceding DEH is due to juvenile unilateral profound deafness (early childhood unilateral profound sensorineural hearing loss of unknown etiology). The incidence of ipsilateral DEH (approximately 60%), in which the ear with profound hearing loss suffers progressive endolymphatic hydrops, is higher than that of the contralateral type of DEH (about 40%), in which the formation of progressive endolymphatic hydrops takes place in the ear opposite to the previously deafened ear. The prevalence of DEH in the general population (23 or less per 100,000) is similar to that of definitive Meniere’s disease, and the distribution of age at onset of DEH closely resembles that of Meniere’s disease except for some patients with childhood onset of DEH. Further, the rate of patients with the contralateral type of DEH (about 40%, although the rate is about 15% if the contralateral type is restricted to patients showing typical Meniere’s symptoms) is similar to that of patients with bilateral Meniere’s disease (about 40%, with a rate of about 14% if Meniere’s disease in the second ear is restricted to definitive Meniere’s disease). Since DEH is closely similar to Meniere’s disease not only in symptoms, but also in many clinical-statistical characteristics, the diseases may be identical in pathogenesis and the pathophysiology of progressive endolymphatic hydrops, although the two conditions have different etiologies.

The Philippine National Ear Institute: Patient and Audiologic Profiles

Background: The Philippine National Ear Institute (PNEI) was created to promote health of hearing and balance among Filipinos. Over the years it, has provided audiologic services to thousands of patients annually and has published relevant hearing and balance research.&#x0D; Objective: To describe the patients served by the PNEI in terms of age, region of origin, occupation, pretest diagnosis, and audiologic results.&#x0D; Methods: &#x0D; Study Design: Cross-sectional study&#x0D; Setting: National tertiary care center&#x0D; Population: All records of patients referred for audiologic testing at PNEI in 2006 were reviewed and encoded into analyzable format.&#x0D; Results: A total of 1,756 patients had audiologic records for review. Median age was 32.5 years, with the age distribution presented according to sex, type of tests done including common reasons for referral, and median threshold levels by frequency. Coverage was national in scope, with most patients coming from the National Capital Region and from Regions III and IVa. Occupation was indicated in 37.8% of the working age group, most of whom were unemployed. The most common pretest diagnosis was chronic otitis media (26.6%), followed by hearing loss of unknown etiology (13.0%) and tinnitus (9.3%). Severity of hearing impairment based on pure tone audiometry was variable, and was presented according to common diagnoses. About 39% of hearing impairment cases were sensorineural, 36% conductive and 25% due to mixed defect. Bilateral Type A ears were found in 45.4% of patients by tympanometry, while 29.3% were bilateral Type B. For otoacoustic emissions, 69.0% were labeled as “refer” in at least one ear.&#x0D; Conclusion: The PNEI is a major national referral center for audiology that holds much promise in developing programs for national surveillance of the hearing status of different sectors in Philippine society.&#x0D; &#x0D; Keywords: Philippine National Ear Institute, Philippines, patient profile, audiology, audiometry, tympanometry, otoacoustic emissions, chronic otitis media

Sensorineural Hearing Loss Associated with Mitochondrial DNA Mutation

A-to-G mutation at nucleotide positions 3243 and 1555 of mitochondrial DNA may cause sensorineural hearing loss. We studied such mutation in patients with bilateral sensorineural hearing loss of unknown etiology, finding 3 cases of A3243G mutation and 1 of A1555G mutation in 46 cases. It 3243 mutation is reported to be associated with diabetes mellitus and maternally inherited sensorineural hearing loss, and our study showed 3 cased of A3243G mutation in 8 cases having both maternally inherited hearing loss and diabetes mellitus. A case of A1555G mutation occurred in 1 case of maternally inherited hearing loss. Hearing loss related to A3243G mutation was characterized by late onset in adulthood and slow progression. That in A1555G mutation was characterized by comparatively rapid hearing loss.

Evaluation of tinnitus patients by peroral multi-drug treatment

To evaluate patients complaining of subjective tinnitus, this study examined their response to peroral betahistine mesilate, vitamin B complex and diazepam in combination. Because three drugs were used together, it remains to be seen whether a single drug or a combination of drugs was effective. We issued questionnaires to 67 patients with tinnitus associated with sensorineural hearing loss of unknown etiology or tinnitus, despite normal hearing in pure tone audiometry and lack of distinct systemic disorders. Our original questionnaire contained seven items and allotted points for each item to facilitate evaluation. After prescribing the above drugs and observing patients’ progress for 5 weeks, 50 of the 67 subjects were evaluated again by the same questionnaire. The present study evaluates tinnitus of patients as an example of clinical applications; this was not a controlled double blind study. It was found that, after patients took the prescribed medication, the total number of points were significantly reduced (paired t-test, P<0.001). After medication, cases of bilateral tinnitus were significantly reduced from 27 to 14, and cases of two types of tinnitus sound, were significantly decreased from 22 to 11 ( χ 2-test, P<0.05). After 5 weeks of administration, 54% of patients felt treatment had been effective. Preliminary results suggest this peroral multi-drug treatment may provide relief for some patients with subjective tinnitus. However, long-term efficacy of the treatment was not investigated.

Phoneme recognition by a non-native English-speaking cochlear implantee using the WSP, MSP, and spectra speech processors: A case study

This study presents the performance of a non-native English-speaking adult using the Nucleus 22 Channel cochlear implant. Included are the subject’s (1) history, (2) promontory stimulation results, (3) audiological information, (4) pre- and post-implantation speech recognition test results, (5) post-implantation auditory phoneme recognition using the wearable speech processor (WSP), the minispeech processor (MSP), and the Spectra processor, and (6) the subject’s subjective reports of benefits in terms of communication and social interactions. The subject, a highly motivated and intelligent male who, presented with a profound bilateral, progressive sensorineural hearing loss of unknown etiology, was 59 years old when the right ear was implanted. Prior to implantation the subject was aided in the left ear, but had never been aided in the right ear. The subject’s performance using each of three processors is presented for medial vowel recognition and medial consonant recognition using auditory stimulation only. Results are displayed through confusion matrices generated based on the subject’s responses to these acoustic stimuli. In summary, the vowel and consonant phoneme recognition of a subject with the Nucleus cochlear implant using various processors is presented. Improved phoneme recognition is demonstrated with filter banking versus feature extraction coding strategies.