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Hearing Loss (hearing + loss)
Kinds of Hearing Loss Selected AbstractsLong-Term Effectiveness of Screening for Hearing Loss: The Screening for Auditory Impairment,Which Hearing Assessment Test (SAI-WHAT) Randomized TrialJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 3 2010Bevan Yueh MD OBJECTIVES: To evaluate the effect of hearing screening on long-term hearing outcomes in a general population of older veterans. DESIGN: Hearing loss in the elderly is underdetected and undertreated. Routine hearing screening has been proposed, but it is not clear whether screening identifies patients who are sufficiently motivated to adhere to treatment. A four-arm randomized clinical trial was conducted to compare three screening strategies with no screening in 2,305 older veterans seeking general medical care. SETTING: Veterans Affairs Puget Sound Health Care System. INTERVENTIONS: The screening strategies were a tone-emitting otoscope, a widely used questionnaire about hearing handicap, and a combination of both tools. MEASUREMENTS: Hearing aid use 1 year after screening. RESULTS: Of participants who underwent screening with the tone-emitting otoscope, questionnaire, and combined testing, 18.6%, 59.2%, and 63.6%, respectively, screened positive for hearing loss (P<.01 for test of equality across three arms). Patients proceeded to formal audiology evaluation 14.7%, 23.0%, and 26.6% of the time in the same screening arms, compared with 10.8% in the control arm (P<.01 for test of equality across four arms). Hearing aid use 1 year after screening was 6.3%, 4.1%, and 7.4% in the same arms, compared with 3.3% in the control arm (P<.01). Hearing aid users experienced significant improvements in hearing-related function and communication ability. CONCLUSION: In older veterans, screening for hearing loss led to significantly more hearing aid use. Screening with the tone-emitting otoscope was more efficient. The results are most applicable to older populations with few cost barriers to hearing aids. [source] Quality Indicators for the Care of Hearing Loss in Vulnerable EldersJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2007Bevan Yueh MD First page of article [source] Challenges and Strategies Related to Hearing Loss Among Dairy FarmersTHE JOURNAL OF RURAL HEALTH, Issue 4 2005Louise Hass-Slavin MSc ABSTRACT: Context: Farming is often imagined to be a serene and idyllic business based on historical images of a man, a horse, and a plow. However, machinery and equipment on farms, such as older tractors, grain dryers, and vacuum pumps, can have noise levels, which may be dangerous to hearing with prolonged, unprotected exposure. Purpose: This qualitative study in Ontario, Canada, explored the challenges and coping strategies experienced by dairy farmers with self-reported hearing loss and communication difficulties. Through in-depth interviews, 13 farmers who experience significant hearing loss were questioned about the challenges they face as a result of hearing loss and the strategies they use to overcome or compensate for problems. Findings: The 2 major challenges encountered by dairy farmers with a hearing loss were: (1) obtaining information from individuals, within groups, and through electronic media; and (2) working with animals, machinery, and noise. To cope with these challenges, participants used strategies identified as problem and emotion focused. Conclusions: Four themes arose from analysis of the challenges encountered and strategies used: 1Hearing loss is experienced as a "familiar," but "private," problem for dairy farmers. 2Communication difficulties can negatively affect the quality of relationships on the farm. 3Safety and risk management are issues when farming with a hearing loss. 4The management or control of excessive noise is a complex problem, because there are no completely reliable yet practical solutions. [source] Medical Malpractice and Hearing LossTHE LARYNGOSCOPE, Issue S1 2009Ryan K. Sewell MD JD No abstract is available for this article. [source] Prevalence and Etiology of Hearing Loss in Rural Nicaraguan ChildrenTHE LARYNGOSCOPE, Issue 3 2007James E. Saunders MD Abstract Objective/Hypothesis: The prevalence and causes of pediatric hearing loss (HL) in the developing world are largely unknown. Infectious sequelae, ototoxic medications, and genetic causes may play a larger role in developing countries. In addition, the significance of GJB2 mutation gene in poorly developed areas remains unclear. The intent of this study is to investigate the prevalence and etiology of HL in children living in a remote, impoverished region of northern Nicaragua. Study Design: Cross-sectional study. Methods: Clinical data from two sources were analyzed: data from screening examinations performed in rural schools in the Department of Jinotega, Nicaragua (group A) and pediatric HL patients seen at the Otolaryngology and Audiology Clinic in Jinotega, Nicaragua (group B). Patients with congenital HL were offered a genetic test for GJB2 mutations. Comparisons were made using parametric (analysis of variance) and nonparametric (Kruskal-Wallis) tests. Results: School-based screening examinations (group A) revealed a high prevalence of significant HL (>30 dB) of 18%. The majority of these children had normal otoscopic examinations (58%). A family history of HL was seen in 24% of children who failed screening exams. Positive family history was more common in patients with HL (P < .01) and in specific schools (P < .05). Clinic-based evaluations (group B) reveal a population with predominantly severe-profound HL. Physical dysmorphism was common, yet identifiable syndromic HL was rare. Although familial HL was common (33%), there were no pathologic GJB2 mutations. Other common risk factors in this population were maternal infection during pregnancy, neonatal distress, low birth weight or prematurity, and gentamicin exposure. Conclusions: HL in this rural, third world environment is more prevalent, and the etiologies responsible in this study group are different from those encountered in industrialized nations. Poor perinatal health care, infectious causes, gentamicin exposure, and hereditary HL are potentially preventable causes that play a major role in this population. [source] Intratympanic Dexamethasone for Sudden Sensorineural Hearing Loss After Failure of Systemic TherapyTHE LARYNGOSCOPE, Issue 1 2007David S. Haynes MD Abstract Objective: Intratympanic steroids are increasingly used in the treatment of inner ear disorders, especially in patients with sudden sensorineural hearing loss (SNHL) who have failed systemic therapy. We reviewed our experience with intratympanic steroids in the treatment of patients with sudden SNHL to determine overall success, morbidity, and prognostic factors. Hypothesis: Intratympanic steroids have minimal morbidity and the potential to have a positive effect on hearing recovery in patients with sudden SNHL who have failed systemic therapy. Study Design: The authors conducted a retrospective review. Methods: Patients presenting with sudden SNHL defined as a rapid decline in hearing over 3 days or less affecting 3 or more frequencies by 30 dB or greater who underwent intratympanic steroids therapy (24 mg/mL dexamethasone) were reviewed. Excluded were patients with Meniere disease, retrocochlear disease, autoimmune HL, trauma, fluctuating HL, radiation-induced HL, noise-induced HL, or any other identifiable etiology for sudden HL. Patients who showed signs of fluctuation of hearing after injection were excluded. Pretreatment and posttreatment audiometric evaluations including pure-tone average (PTA) and speech reception threshold (SRT) were analyzed. Patient variables as they related to recovery were studied and included patient age, time to onset of therapy, status of the contralateral ear, presence of diabetes, severity of HL, and presence of associated symptoms (tinnitus, vertigo). A 20-dB gain in PTA or a 20% improvement in SDS was considered significant. Results: Forty patients fit the criteria for inclusion in the study. The mean age of the patients was 54.8 years with a range from 17 to 84 years of age. Overall, 40% (n = 16) showed any improvement in PTA or SDS. Fourteen (35%) men and 26 (65%) women were included. Using the criteria of 20-dB improvement in PTA or 20% improvement in SDS for success, 27.5% (n = 11) showed improvement. The mean number of days from onset of symptoms to intratympanic therapy was 40 days with a range of 7 days to 310 days. A statistically significant difference was noted in those patients who received earlier injection (P = .0008, rank sum test). No patient receiving intratympanic dexamethasone after 36 days recovered hearing using 20-dB PTA decrease or a 20% increase in discrimination as criteria for recovery. Twelve percent (n = 5) of patients in the study had diabetes with 20% recovering after intratympanic dexamethasone (not significantly different from nondiabetics at 28.6%, Fisher exact test, P = 1.0). Comparison to other studies that used differing steroid type, concentration, dosing schedule, inclusion criteria, and criteria for success revealed, in many instances, a similar overall recovery rate. Conclusions: Difficulty in proving efficacy of a single modality is present in all studies on SNHL secondary to multiple treatment protocols, variable rates of recovery, and a high rate of spontaneous recovery. Forty percent of patients showed some improvement in SDS or PTA after treatment failure. When criteria of 20-dB PTA or 20% is considered to define improvement, the recovery rate was 27.5%. Modest improvement is seen with the current protocol of a single intratympanic steroid injection of 24 mg/mL dexamethasone in patients who failed systemic therapy. Dramatic hearing recovery in treatment failures was rarely encountered. No patient showed significant benefit from intratympanic steroids after 36 days when using this protocol for idiopathic sudden SNHL. If patients injected after 6 weeks are excluded from the study, the improvement rate increases from 26.9% to 39.3%. Earlier intratympanic injection had a significant impact on hearing recovery, although with any therapeutic intervention for sudden SNHL, early success may be attributed to natural history. If we further exclude seven patients treated with intratympanic steroids within 2 weeks of the onset of symptoms (i.e., study only those patients treated with intratympanic dexamethasone between 2 and 6 weeks after onset of symptoms), still, 26% improved by 20 dB or 20% SDS. The recovery rates after initial systemic failure are higher than would be expected in this treatment failure group given our control group (9.1%) and literature review. These findings indicate a positive effect from steroid perfusion in this patient population. [source] Presbycusis: A Human Temporal Bone Study of Individuals With Downward Sloping Audiometric Patterns of Hearing Loss and Review of the LiteratureTHE LARYNGOSCOPE, Issue S112 2006Erik G. Nelson MD Abstract Objective: The purpose of this retrospective case review was to identify patterns of cochlear element degeneration in individuals with presbycusis exhibiting downward sloping audiometric patterns of hearing loss and to correlate these findings with those reported in the literature to clarify conflicting concepts regarding the association between hearing loss and morphologic abnormalities. Methods: Archival human temporal bones from individuals with presbycusis were selected on the basis of strict audiometric criteria for downward-sloping audiometric thresholds. Twenty-one temporal bones that met these criteria were identified and compared with 10 temporal bones from individuals with normal hearing. The stria vascularis volumes, spiral ganglion cell populations, inner hair cells, and outer hair cells were quantitatively evaluated. The relationship between the severity of hearing loss and the degeneration of cochlear elements was analyzed using univariate linear regression models. Results: Outer hair cell loss and ganglion cell loss was observed in all individuals with presbycusis. Inner hair cell loss was observed in 18 of the 21 individuals with presbycusis and stria vascularis loss was observed in 10 of the 21 individuals with presbycusis. The extent of degeneration of all four of the cochlear elements evaluated was highly associated with the severity of hearing loss based on audiometric thresholds at 8,000 Hz and the pure-tone average at 500, 1,000, and 2,000 Hz. The extent of ganglion cell degeneration was associated with the slope of the audiogram. Conclusions: Individuals with downward-sloping audiometric patterns of presbycusis exhibit degeneration of the stria vascularis, spiral ganglion cells, inner hair cells, and outer hair cells that is associated with the severity of hearing loss. This association has not been previously reported in studies that did not use quantitative methodologies for evaluating the cochlear elements and strict audiometric criteria for selecting cases. [source] Two Temporal Bone Computed Tomography Measurements Increase Recognition of Malformations and Predict Sensorineural Hearing Loss,THE LARYNGOSCOPE, Issue 8 2006Derk D. Purcell MD Abstract Objectives/Hypothesis: The objectives of this prospective study were to assess the reproducibility of the measurements of the cochlea and lateral semicircular canal (LSCC) and to determine if abnormal measurements predict sensorineural hearing loss (SNHL). Methods: Two readers independently measured the cochlear height on coronal section and the LSCC bony island width on axial section on 109 temporal bone computed tomography scans; audiologic data on these patients were collected independently from medical records. Inter- and intrareader variability was evaluated using intraclass correlation coefficients (ICCs) based on a random-effects model. The positive and negative predictive values of abnormal measurement for hearing loss were determined. Results: There was excellent inter- and intraobserver agreement for both measurements (ICC >80%). The average cochlear height was 5.1 mm (normal range, 4.4,5.9 mm) and average LSCC bony island width was 3.7 mm (normal range, 2.6,4.8 mm). Review of the original radiology reports demonstrated that both cochlear hypoplasia and LSSC dysplasia were overlooked in >50% of patients with both abnormal measurements and SNHL. Cochlear hypoplasia (<4.4 mm) had a positive predictive value of 100% for SNHL, whereas cochlear hyperplasia and bony island dysplasia were less predictive. Conclusion: The measurements of coronal cochlear height and axial LSCC bony width have excellent reproducibility and identify bony labyrinth abnormalities missed by visual inspection alone. In addition, cochlear hypoplasia is highly predictive of SNHL. To reliably identify inner ear malformations, measurement of the cochlear height and LSCC bony island width, in addition to the vestibular aqueduct, should be routinely performed on all temporal bone studies. [source] Intratympanic Dexamethasone Injection for Refractory Sudden Sensorineural Hearing LossTHE LARYNGOSCOPE, Issue 5 2006Yun-Hoon Choung DDS Abstract Objective: This case-control study aimed to analyze the effect of intratympanic dexamethasone injection (ITDI) as a treatment option for patients with sudden sensorineural hearing loss (SSNHL) who were refractory to classic oral steroid treatment. Methods: Sixty-six patients with SSNHL, who were refractory to a course of oral steroid therapy, were included in this study. We prospectively treated consecutive 33 patients (34 ears) with ITDI from August 2002 to January 2004. We then retrospectively collected data from age- and sex-matched previous patients who did not take any more treatments after the initial regimen between March 2000 and July 2002. ITDI was performed in the supine position on four separate occasions over the course of 2 weeks. Hearing was assessed immediately before every injection and at 1 week after therapy. Hearing improvement was defined as more than 10 dB in pure-tone average (PTA). Results: Hearing improvement was observed in 13 (39.4%) of 33 patients who underwent ITDI and in two (6.1%) of 33 patients in the control group. Five of 13 represented hearing improvement over than 20 dB in PTA, and 11 of 20 patients, who showed no improvement in PTA by ITDI, showed improvement over 10 dB in some frequencies. There were no definite prognostic factors between the patients who responded to ITDI and those who did not. Conclusion: ITDI may be a simple and effective therapy for patients with refractory SSNHL. [source] Diameter of the Cochlear Nerve in Endolymphatic Hydrops: Implications for the Etiology of Hearing Loss in Ménière's Disease,THE LARYNGOSCOPE, Issue 9 2005Cliff A. Megerian MD Abstract Objective/Hypothesis: Endolymphatic hydrops (ELH) is an important histopathological hallmark of Ménière's disease. Experimental data from human temporal bones as well as animal models of the disorder have generally failed to determine the mechanism by which ELH or related pathology causes hearing loss. Hair cell and spiral ganglion cell counts in both human and animal case studies have not, for the most part, shown severe enough deterioration to explain associated severe sensorineural hearing loss. However a limited number of detailed ultrastructural studies have demonstrated significant reductions in dendritic innervation densities, raising the possibility that neurotoxicity plays an important role in the pathology of Ménière's disease (MD) as well as experimental endolymphatic hydrops (ELH). This study tests the hypothesis that neurotoxicity is an important primary mediator of injury to the hydropic ear and is reflected in measurable deterioration of the cochlear nerve in the animal model of ELH. This study also explores the previously presented hypothesis that cochlear injury in ELH is mediated through the actions of nitric oxide (NO) by evaluating whether hearing loss or various measures of cochlear damage can be ameliorated by administration of an agent that limits excess production of NO. Study Design: Part one of the project involves the surgical induction of endolymphatic hydrops and correlation of long term hearing loss with histological parameters of ELH severity as well as cochlear nerve and eighth cranial nerve diameter measurements. In part two, aminoguanidine is administered orally to a separate set of hydropic animals in an attempt to limit cochlear injury presumably mediated by NO. Methods: Guinea pigs are subjected to surgical induction of unilateral endolymphatic hydrops after establishing baseline ABR thresholds at 2, 4, 8, 16, and 32 kHz. Threshold shifts are established prior to sacrifice at 4 to 6 months and temporal bones processed for light microscopy. Measurements of cochlear nerve and eighth cranial nerve maximal diameters as well as average maximal diameters are carried out and correlated to hearing loss and a semi-quantitative measure of hydrops severity. The identical experiments are carried out in animals treated with aminoguanidine, an inhibitor of inducible nitric oxide synthase. Results: The mean maximal diameter (n = 14) of the hydropic cochlear nerve was significantly reduced (432.14 ± 43.18 vs. 479.28 ± 49.22 microns, P = .0025) as compared to the control nerve. This was also seen in measures of the eighth cranial nerve (855.71 ± 108.82 vs. 929 ± 81.53 microns, P = 0.0003). Correlation studies failed to show correlation between hydrops severity and a cochlear nerve deterioration index (r = -0.0614, P = .8348). Similarly, hearing loss severity failed to correlate with cochlear nerve deterioration (r = 0.1300, P = .6577). There was a significant correlation between hearing loss and hydrops severity (r = 0.6148, P = .0193). Aminoguanidine treated animals (n = 5) also sustained nerve deterioration to the same degree as non-treated animals and there appeared to be no protective effect (at the dosage administered) against ELH related hearing loss, hydrops formation, or nerve deterioration. Conclusion: ELH results in significant deterioration of cochlear nerve and eighth cranial nerve maximal diameters in the guinea pig model. These findings are in accord with previous studies which detected ultrastructural evidence of dendritic damage and indicate that neural injury is of sufficient severity to result in light microscopic evidence of cochlear nerve and eighth cranial nerve deterioration. These data support the concept that the principle pathological insult in ELH is a form of neurotoxicity, especially in light of previous studies which indicate relative preservation of hair cells at similar points in time. The lack of correlation between the severity of hydrops and nerve deterioration suggests that nerve deterioration is independent of hydrops severity. [source] Hearing Loss in Union Army Veterans from 1862 to 1920,THE LARYNGOSCOPE, Issue 12 2004Ryan K. Sewell MD Abstract Objectives: To examine the prevalence of hearing loss (HL) in Union Army (UA) veterans by year, birth cohort, and occupation, and to compare Civil War pension and contemporary disability programs by examining monthly dollar awards. Study Design: A retrospective review of medical records for 17,722 UA veteran pension applicants, a subset of some 35,000 soldiers retrieved randomly from the Military Archives. Methods: The diagnosis of HL was based on review of medical records, which used gross measurements because of the unavailability of audiometric testing. Results: One third (5,891 or 33%) of pensioners sampled received compensation for HL. The veterans with HL suffered predominantly from left-sided HL (4,091 or 70%), which is consistent with noise-induced HL in a right-handed individual firing a rifle. Comparison of civilian occupations reveals minimal variation in prevalence of HL. Civil War pensions for unilateral HL averaged $134.04 per year, representing nearly one third of the average annual income in 1890. Bilateral HL received nearly twice that amount. Today, military veterans receive $1,248 annually for unilateral loss and $27,288 annually for bilateral loss. Social Security disability benefits are granted only for bilateral HL, with an average 60-year-old individual receiving $11,400 per year. Conclusion: HL was a common disability among UA Civil War veterans, with noise exposure a likely etiology for the HL. The differing levels of compensation for HL may reflect differing perceptions on the incapacitating effects of HL. [source] Auditory Brainstem Response versus Magnetic Resonance Imaging for the Evaluation of Asymmetric Sensorineural Hearing Loss,THE LARYNGOSCOPE, Issue 10 2004Roberto A. Cueva MD Abstract Objectives/Hypothesis: Auditory brainstem response (ABR) testing and magnetic resonance imaging (MRI) are compared for the evaluation of patients with asymmetric sensorineural hearing loss (SNHL). MRI with gadolinium administration is the current gold standard for identifying retrocochlear lesions causing asymmetric SNHL. The study seeks to determine the sensitivity and specificity of ABR in screening for possible retrocochlear pathology. Most important among SNHL etiologies are neoplastic lesions such as vestibular schwannomas, cerebellopontine angle (CPA) tumors, as well as multiple sclerosis, stroke, or other rare nonneoplastic causes. The study results will allow the author to recommend a screening algorithm for patients with asymmetric SNHL. Study Design: The study is a multi-institutional, institutional review board approved, prospective, nonrandomized comparison of ABR and MRI for the evaluation of patients with asymmetric SNHL. Methods: Three hundred twelve patients (between the ages of 18 and 87) with asymmetric SNHL completed the study. Asymmetric SNHL was defined as 15 dB or greater asymmetry in two or more frequencies or 15% or more asymmetry in speech discrimination scores (SDS). These patients prospectively underwent both ABR and MRI. The ABR and MRI were interpreted independently in a blinded fashion. In addition to the ABR and MRI results, a variety of clinical and demographic data were collected. Results: Thirty-one (9.94%) patients of the study population of 312 were found on MRI to have lesions causing their SNHL. Of the 31 patients with causative lesions on MRI there were 24 vestibular schwannomas, 2 glomus jugulare tumors, 2 ectatic basilar arteries with brainstem compression, 1 petrous apex cholesterol granuloma, 1 case of possible demyelinating disease, and 1 parietal lobe mass. Twenty-two of the 31 patients had abnormal ABRs, whereas 9 patients (7 with small vestibular schwannomas) had normal ABRs. This gives an overall false-negative rate for ABR of 29%. The false-positive rate was found to be 76.84%. Sensitivity of ABR as a screening test was 71%, and specificity was 74%. Conclusions: Ten percent of patients with asymmetric SNHL (by this study's criteria) are likely to have causative lesions found on MRI. Although the recently reported annual incidence of vestibular schwannoma in the general population is 0.00124%, for patients with asymmetric SNHL in this study, the incidence was 7.7% (nearly 4 orders of magnitude higher). ABR has been demonstrated to have low sensitivity and specificity in the evaluation of these patients and cannot be relied on as a screening test for patients with asymmetric SNHL. Keeping the use of MRI conditional on the results of ABR will annually result in missed or delayed diagnosis of causative lesions in 29 patients per 1,000 screened. The author recommends abandoning ABR as a screening test for asymmetric SNHL and adoption of a focused MRI protocol as the screening test of choice (within certain guidelines). [source] The Mechanism of Hearing Loss in Paget's Disease of Bone,THE LARYNGOSCOPE, Issue 4 2004Edwin M. Monsell MD Abstract Objectives/Hypothesis The mechanism of hearing loss (HL) in Paget's disease of bone was investigated. The present study was a systematic, prospective, controlled set of clinical investigations to test the hypothesis that there is a general underlying mechanism of HL in Paget's disease of bone and to gain additional insights into the auditory and otologic dynamics of this disease. Specific questions were 1) whether the mechanism is cochlear or retrocochlear and 2) whether the bone mineral density of the cochlear capsule is related to hearing levels. Study Design Several double-blinded, cross-sectional, prospective, correlational studies were conducted in a population of elderly human subjects with skull involvement with Paget's disease versus a control population of elderly subjects free of Paget's disease. Demographic and clinical data were recorded. Longitudinal observations were made in subjects under treatment. Methods Subjects were recruited from a Paget's disease clinic. Pure-tone auditory thresholds, word recognition, and auditory brainstem responses (ABRs) were recorded. The dimensions of the internal auditory canals were measured using computed tomographic (CT) images and digital image analysis. The precision, accuracy, and temporal stability of methods to measure the bone mineral density of the cochlear capsule and an adjacent area of nonotic capsule bone were validated and applied. Correlations were sought between hearing levels and cochlear capsule bone mineral density. Results ABRs were recorded in 64 ears with radiographically confirmed Paget's disease involving the skull. Responses were absent in eight ears, all of which had elevated high pure-tone thresholds. ABRs were interpreted as normal in 56 ears; none were abnormal. The mid-length diameter and minimum diameter of the internal auditory canal of 68 temporal bones from subjects with Paget's disease were found to have no statistically significant relationship to hearing thresholds. The Pearson product-moment correlation coefficients (age- and sex-adjusted) in the group with Paget's disease involving the temporal bone were ,0.63 for left ears and ,0.73 for right ears for high-frequency air conduction pure-tone thresholds (mean of 1, 2, and 4 kHz) versus cochlear capsule density. Correlation coefficients (age- and sex-adjusted) between cochlear capsule density and air-bone gap (mean at 0.5 and 1 kHz) for the affected group were ,0.67 for left ears and ,0.63 for right ears. All correlations between hearing thresholds and cochlear capsule density in pagetic subjects were significant at P < .001. The regressions were consistent throughout the ranges of hearing level. There were no significant correlations between cochlear capsule mean density and hearing level in the volunteer subjects. Conclusions The evidence supports the existence of a general, underlying, cochlear mechanism of pagetic HL that is closely related to loss of bone mineral density in the cochlear capsule. This mechanism accounts well for both the high-frequency sensorineural HL and the air-bone gap. Early identification, radiographic diagnosis of temporal bone involvement, and vigorous treatment with third-generation bisphosponates are important to limit the development and progression of pagetic HL. [source] Candidate's Thesis: Platelet-Activating Factor,Induced Hearing Loss: Mediated by Nitric Oxide?,THE LARYNGOSCOPE, Issue 12 2003Chung-Ku Rhee MD Abstract Objectives/Hypothesis Platelet-activating factor (PAF)in middle ear effusion is thought to induce hearing loss. The purpose of this study is to investigate the role of nitric oxide (NO) in the mechanism of PAF-induced hearing loss by studying the effects of PAF application on the round window membrane (RWM) with and without PAF-antagonist NO-blocker. Study Design Longitudinal study on randomized guinea pigs using PAF to induce hearing loss. Methods Guinea pigs were divided into four groups: PBS, PAF, PAF-antagonist, and L-NAME. The PBS group received phosphate buffered saline (PBS) and the PAF groups received 10, 20, and 40 ,g of PAF soaked into gelfoam and placed on the RWM. PAF-antagonist (WEB 2170) and NOS inhibitor NG-nitro-l-arginine-methylester (L-NAME) were injected intraperitoneally prior to PAF 20 ,g application on the RWM. The following three tests were performed on each animal group: Hearing was tested with an auditory brainstem response (ABR) test over 24 hours. At the end of 24 hours, cochlear hair cells were examined by scanning electron microscopy (SEM) and immunohistochemistry was carried out on the cochlea to test the expression of inducible nitric oxide synthase (iNOS). Results The PAF group developed significant elevation of ABR threshold and cochlear hair cell damage in the SEM group as compared with the PBS control group. The PAF-antagonist (WEB 2170) and the L-NAME groups did not show significant elevation of ABR threshold and cochlear hair cell damage compared with the group administered PAF 20 ,g, but in the PAF-antagonist group, the elevation of ABR threshold was significant compared with that of the PBS control group, whereas it was not significant compared with the PBS group in the L-NAME group. Strong expression of iNOS on cochlea was observed in the PAF group and lighter expression was seen in PBS, WEB 2170, and L-NAME groups. Conclusions This study demonstrated that PAF placed on the RWM induced hearing loss and cochlear hair cell damage. The PAF-antagonists and L-NAME prevented the PAF-induced hearing loss and inhibited iNOS expression in the cochlea. These findings suggest that the PAF-induced hearing loss caused by cochlear hair cell damage may have been mediated by NO. PAF-antagonists and L-NAME may have future therapeutic implications in preventing sensorineural hearing loss associated with chronic otitis media. The results of this study have significant potential clinical application. [source] Enhancing Intrinsic Cochlear Stress Defenses to Reduce Noise-Induced Hearing Loss,,§THE LARYNGOSCOPE, Issue 9 2002Richard D. Kopke COL MC USA Abstract Objectives/Hypothesis Oxidative stress plays a substantial role in the genesis of noise-induced cochlear injury that causes permanent hearing loss. We present the results of three different approaches to enhance intrinsic cochlear defense mechanisms against oxidative stress. This article explores, through the following set of hypotheses, some of the postulated causes of noise-induced cochlear oxidative stress (NICOS) and how noise-induced cochlear damage may be reduced pharmacologically. 1) NICOS is in part related to defects in mitochondrial bioenergetics and biogenesis. Therefore, NICOS can be reduced by acetyl-L carnitine (ALCAR), an endogenous mitochondrial membrane compound that helps maintain mitochondrial bioenergetics and biogenesis in the face of oxidative stress. 2) A contributing factor in NICOS injury is glutamate excitotoxicity, which can be reduced by antagonizing the action of cochlear N -methyl-D-aspartate (NMDA) receptors using carbamathione, which acts as a glutamate antagonist. 3) Noise-induced hearing loss (NIHL) may be characterized as a cochlear-reduced glutathione (GSH) deficiency state; therefore, strategies to enhance cochlear GSH levels may reduce noise-induced cochlear injury. The objective of this study was to document the reduction in noise-induced hearing and hair cell loss, following application of ALCAR, carbamathione, and a GSH repletion drug D-methionine (MET), to a model of noise-induced hearing loss. Study Design This was a prospective, blinded observer study using the above-listed agents as modulators of the noise-induced cochlear injury response in the species chinchilla laniger. Methods Adult chinchilla laniger had baseline-hearing thresholds determined by auditory brainstem response (ABR) recording. The animals then received injections of saline or saline plus active experimental compound starting before and continuing after a 6-hour 105 dB SPL continuous 4-kHz octave band noise exposure. ABRs were obtained immediately after noise exposure and weekly for 3 weeks. After euthanization, cochlear hair cell counts were obtained and analyzed. Results ALCAR administration reduced noise-induced threshold shifts. Three weeks after noise exposure, no threshold shift at 2 to 4 kHz and <10 dB threshold shifts were seen at 6 to 8 kHz in ALCAR-treated animals compared with 30 to 35 dB in control animals. ALCAR treatment reduced both inner and outer hair cell loss. OHC loss averaged <10% for the 4- to 10-kHz region in ALCAR-treated animals and 60% in saline-injected-noise-exposed control animals. Noise-induced threshold shifts were also reduced in carbamathione-treated animals. At 3 weeks, threshold shifts averaged 15 dB or less at all frequencies in treated animals and 30 to 35 dB in control animals. Averaged OHC losses were 30% to 40% in carbamathione-treated animals and 60% in control animals. IHC losses were 5% in the 4- to 10-kHz region in treated animals and 10% to 20% in control animals. MET administration reduced noise-induced threshold shifts. ANOVA revealed a significant difference (P <.001). Mean OHC and IHC losses were also significantly reduced (P <.001). Conclusions These data lend further support to the growing body of evidence that oxidative stress, generated in part by glutamate excitotoxicity, impaired mitochondrial function and GSH depletion causes cochlear injury induced by noise. Enhancing the cellular oxidative stress defense pathways in the cochlea eliminates noise-induced cochlear injury. The data also suggest strategies for therapeutic intervention to reduce NIHL clinically. [source] Use of Laboratory Evaluation and Radiologic Imaging in the Diagnostic Evaluation of Children With Sensorineural Hearing Loss,THE LARYNGOSCOPE, Issue 1 2002Derek D. Mafong BS Abstract Objective Laboratory testing and radiologic imaging are commonly used to delineate syndromic from nonsyndromic sensorineural HL (SNHL). The aim of this study was to examine the yield of laboratory tests and radiologic imaging commonly used in the diagnostic evaluation of SNHL in children. Study Design Retrospective analysis of 114 (54 female, 60 male) consecutively investigated children with SNHL between 1998 and 2000 at a tertiary-care university hospital. Methods Results of routine laboratory testing to assess autoimmunity, blood dyscrasias, endocrine abnormalities, renal function, infection, and cardiac testing were reviewed. Results of radiologic evaluation were also reviewed. In general, computed tomography (CT) was obtained in patients with symmetric SNHL, whereas magnetic resonance imaging (MRI) with or without CT was obtained in asymmetric SNHL. Results Laboratory evaluation of the blood did not yield the etiology of SNHL in any patient. Blood tests for autoimmune disease were often positive but did not correlate with clinical disease. Nonspecific elevation of erythrocyte sedimentation rate (ESR) and antinuclear antibody (ANA) was present in 22% of cases. An abnormal electrocardiogram with a prolonged QT interval resulted in the diagnosis of Jervall and Lange-Nielsen syndrome. In the 97 patients who underwent radiologic studies, abnormalities were present in 38 of 97 studies (39%). Isolated inner ear malformations were twice as common as multiple abnormalities with large vestibular aqueducts as the most common isolated finding. Conclusion In the evaluation of children with unexplained SNHL, routine laboratory evaluation should be reconsidered given its low diagnostic yield. However, radiologic abnormalities of the inner ear are common. Identification of inner ear malformations has direct impact on management of these children, suggesting that all children should undergo radiologic imaging as an integral component of evaluation of SNHL. [source] Autoimmune Sensorineural Hearing Loss in Young Patients: An Exploratory StudyTHE LARYNGOSCOPE, Issue 11 2001Jean-Paul Tomasi MD Abstract Objectives P0 protein is expressed exclusively in myelinating Schwann cells of the peripheral nervous system. In a previous study from our laboratory, 27% of patients with sensorineural hearing loss (SNHL) had antibodies to P0 protein in their serum. The purpose of the present exploratory study was to examine the relationship between the clinical presentation of SNHL among children and young adults (age range, 5,30 y) and the presence of serum anti-P0 antibodies. Study Design The data were collected by retrospective questionnaires from Belgian otolaryngologists. Methods Patients were divided for comparison into two groups according to the presence or absence of anti-P0 antibodies. Results Analyses of clinical data and audiometric results indicated that a progressive hearing loss was more frequently recorded in the patients in the anti-P0 antibody,positive group (82% [14 of 17]) than in those in the anti-P0 antibody,negative group (35% [6 of 17]) (P <.005). Conclusions Thus, in the age group in the present study, autoimmune SNHL (as measured in the present study by the presence of anti-P0 antibodies) is more frequently associated with progressive than with sudden hearing loss. The implications of this finding for preventive screening of hearing loss in children and young adults are discussed. [source] Progressive Sensorineural Hearing Loss in Children With Mitochondrial Encephalomyopathies,THE LARYNGOSCOPE, Issue 3 2001Priv. Doz. Abstract Objective Mitochondrial disorders are responsible for a variety of neurological syndromes. Specific mitochondrial DNA mutations have been identified recently in some of these rare disorders. Clinical symptoms may occur in different organs to various extent; often they are associated with progressive hearing loss. The aims of this study were to determine incidence, onset, and characteristics of hearing loss in children with mitochondrial encephalomyopathies and to investigate a possible correlation between the degree of hearing loss and neurological symptoms. In addition, we investigated the prognostic value of hearing loss as a predictor of the disease. Study Design From August 1992 to September 1998, 29 patients ranging in age from 5 to 23 years (mean years) were studied. These children were hospitalized for diagnostic purposes in the neuropediatric department. Methods The mitochondrial disorder was diagnosed by clinical and laboratory testings, including analysis of the mtDNA. Audiological evaluation consisted of measurements of pure-tone and speech audiometry, tympanometry, and acoustic refle- threshold testing, auditory brainstem response, and evoked as well as distortion-product otoacoustic emissions. Results A sensorineural hearing loss was identified in 12 children. Three of these were diagnosed as having classic Kearns-Sayre syndrome; five as having multisystem KSS; two as having the syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS); one as having KSS-MELAS overlap syndrome; and one as having Friedreich ataxia. Longitudinal testing was performed in seven children, and in all of them a progression of the hearing loss could be demonstrated. Audiological test results in all 12 children suggested cochlear as well as retrocochlear origin of the hearing loss presenting independently from the severity of hearing impairment. No correlation between the characteristics and degrees of hearing loss and the number and severity of clinical neurological symptoms could be found. Conclusions The present study demonstrated a high incidence (42%) of sensorineural hearing loss in children with mitochondrial encephalomyopathies. The progressive nature of the hearing impairment was confirmed by a significant correlation between the duration in years and severity of hearing loss in the children. The hearing loss does not have a prognostic value for the progression of the disorder. Based on our findings, we recommend regular audiometric examinations in patients with mitochondrial disorders. [source] Spectrum and Frequency of SLC26A4 Mutations Among Czech Patients with Early Hearing Loss with and without Enlarged Vestibular Aqueduct (EVA)ANNALS OF HUMAN GENETICS, Issue 4 2010Radka Pourová Summary Mutations in SLC26A4 cause Pendred syndrome (PS) , hearing loss with goitre , or DFNB4 , non-syndromic hearing loss (NSHL) with inner ear abnormalities such as Enlarged Vestibular Aqueduct (EVA) or Mondini Dysplasia (MD). We tested 303 unrelated Czech patients with early hearing loss (298 with NSHL and 5 with PS), all GJB2 -negative, for SLC26A4 mutations and evaluated their clinical and radiological phenotype. Among 115 available HRCT/MRI scans we detected three MD (2.6%), three Mondini-like affections (2.6%), 16 EVA (13 bilateral , 19.2% and 15.6% respectively) and 61 EVA/MD-negative scans (73.4%). We found mutation(s) in 26 patients (8.6%) and biallelic mutations in eight patients (2.7%) out of 303 tested. In 18 of 26 (69%) patients, no second mutation could be detected even using MLPA. The spectrum of SLC26A4 mutations in Czech patients is broad without any prevalent mutation. We detected 21 different mutations (four novel). The most frequent mutations were p.Val138Phe and p.Leu445Trp (18% and 8.9% of pathogenic alleles respectively). Among 13 patients with bilateral EVA, six patients (50%) carry biallelic mutations. In EVA -negative patients no biallelic mutations were found but 4.9% had monoallelic mutations. SLC26A4 mutations are present mostly in patients with EVA/MD and/or progressive HL and those with affected siblings. [source] Analysis of Gene Polymorphisms Associated with K+ Ion Circulation in the Inner Ear of Patients Susceptible and Resistant to Noise-induced Hearing LossANNALS OF HUMAN GENETICS, Issue 4 2009Malgorzata Pawelczyk Summary Noise-induced hearing loss (NIHL) is one of the leading occupational health risks in industrialized countries. It results from an interaction between environmental and genetic factors, however the nature of the genetic factors contributing to NIHL has not yet been clarified. Here, we investigated whether genetic variations in 10 genes putatively involved in the potassium recycling pathway in the inner ear may influence susceptibility to noise. 99 SNPs were genotyped in Polish noise-exposed workers, categorized into susceptible and resistant subjects. The most interesting results were obtained for KCNE1 and KCNQ4 as we replicated associations that were previously reported in a Swedish sample set, hence confirming that they are NIHL susceptibility genes. Additionally we report significant associations in GJB1, GJB2, GJB4, KCNJ10 and KCNQ1, however due to the lack of replication in the Swedish sample set, these results should be seen as suggestive. [source] Candidate Gene Association Study for Noise-induced Hearing Loss in Two Independent Noise-exposed PopulationsANNALS OF HUMAN GENETICS, Issue 2 2009A. Konings Summary Millions of people are daily exposed to high levels of noise. Consequently, noise-induced hearing loss (NIHL) is one of the most important occupational health hazards worldwide. In this study, we performed an association study for NIHL based on a candidate gene approach. 644 Single Nucleotide Polymorphisms (SNPs) in 53 candidate genes were analyzed in two independent NIHL sample sets, a Swedish set and part of a Polish set. Eight SNPs with promising results were selected and analysed in the remaining part of the Polish samples. One SNP in PCDH15 (rs7095441), resulted in significant associations in both sample sets while two SNPs in MYH14 (rs667907 and rs588035), resulted in significant associations in the Polish sample set and significant interactions with noise exposure level in the Swedish sample set. Calculation of odds ratios revealed a significant association of rs588035 with NIHL in the Swedish high noise exposure level group. Our studies suggest that PCDH15 and MYH14 may be NIHL susceptibility genes, but further replication in independent sample sets is mandatory. [source] Morphological Correlates of Acute and Permanent Hearing Loss During Experimental Pneumococcal MeningitisBRAIN PATHOLOGY, Issue 2 2003Matthias Klein In patients with acute bacterial meningitis, hearing loss can be transient but is often permanent. The mechanisms underlying meningitis-associated hearing loss are not fully understood. Therefore, we investigated the morphological correlates of hearing loss in a rat model of pneumococcal meningitis. Transcutaneous intracisternal injection of Streptococcus pneumoniae resulted in a dose-dependent hearing loss (determined by auditory brainstem response audiometry), which was partially reversible during the acute stage. Nevertheless, a severe permanent hearing loss persisted until 2 weeks after infection. Suppurative labyrinthitis was accompanied by blood-labyrinth barrier disruption (determined by cochlear Evans blue extravasation), which correlated closely with hearing loss during the acute stage but not after recovery. Two weeks after infection, spiral ganglion neuronal density was markedly decreased and correlated with the severity of permanent hearing loss. Neuronal loss can be explained by the new finding of meningitis-associated spiral ganglion neuronal necrosis rather than apop-tosis (determined by morphology, TUNEL staining, and immunohistochemistry). [source] Hearing loss in Fabry disease: data from the Fabry Outcome SurveyEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 9 2006S. Hegemann Abstract Background, Hearing loss is a common symptom in Fabry disease, but neither its natural course nor its aetiology has been defined precisely. The aim of this study was to provide a detailed epidemiological description of hearing impairment in patients in the Fabry Outcome Survey (FOS), which is the largest available database of Fabry patients. Materials and methods, Questionnaires were completed by 566 Fabry patients, of whom 316 reported ear-related symptoms. Pure-tone audiograms from 86 patients, performed before starting enzyme replacement therapy, were analysed and compared with age- and sex-specific normal values (International Organization for Standardization, ISO 7029). Results, When compared to an age-matched population (ISO 7029), 74% of patients had a threshold elevated above the 95th centile in at least one tested frequency. All frequencies were affected to a similar degree. However, only 14 patients (16%) were clinically affected by hearing impairment according to the age-independent World Health Organization (WHO) classification (mean threshold at 0·5, 1 and 2 kHz worse than 25 dB). Hearing loss was sensorineural in 63 patients (73%) of whom 7 patients (8%) had also a conductive component. One patient had a purely conductive hearing loss. Episodes of sudden hearing loss seemed to occur more frequently than in the general population. Men were affected earlier and more severely than women. Conclusions, Hearing in Fabry disease is significantly worse than in an age-matched general population but leads to clinically relevant hearing impairment in only 16% of cases. It resembles accelerated presbycusis with an additional Fabry-specific strial-type hearing loss. [source] Long-Term Effectiveness of Screening for Hearing Loss: The Screening for Auditory Impairment,Which Hearing Assessment Test (SAI-WHAT) Randomized TrialJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 3 2010Bevan Yueh MD OBJECTIVES: To evaluate the effect of hearing screening on long-term hearing outcomes in a general population of older veterans. DESIGN: Hearing loss in the elderly is underdetected and undertreated. Routine hearing screening has been proposed, but it is not clear whether screening identifies patients who are sufficiently motivated to adhere to treatment. A four-arm randomized clinical trial was conducted to compare three screening strategies with no screening in 2,305 older veterans seeking general medical care. SETTING: Veterans Affairs Puget Sound Health Care System. INTERVENTIONS: The screening strategies were a tone-emitting otoscope, a widely used questionnaire about hearing handicap, and a combination of both tools. MEASUREMENTS: Hearing aid use 1 year after screening. RESULTS: Of participants who underwent screening with the tone-emitting otoscope, questionnaire, and combined testing, 18.6%, 59.2%, and 63.6%, respectively, screened positive for hearing loss (P<.01 for test of equality across three arms). Patients proceeded to formal audiology evaluation 14.7%, 23.0%, and 26.6% of the time in the same screening arms, compared with 10.8% in the control arm (P<.01 for test of equality across four arms). Hearing aid use 1 year after screening was 6.3%, 4.1%, and 7.4% in the same arms, compared with 3.3% in the control arm (P<.01). Hearing aid users experienced significant improvements in hearing-related function and communication ability. CONCLUSION: In older veterans, screening for hearing loss led to significantly more hearing aid use. Screening with the tone-emitting otoscope was more efficient. The results are most applicable to older populations with few cost barriers to hearing aids. [source] A contiguous deletion syndrome of X-linked agammaglobulinemia and sensorineural deafnessPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 2 2001Darko Richter Hearing loss in patients with X-linked agammaglobulinemia is often attributed to recurrent infections. However, recent genetic studies suggest a different etiology in some patients. We present three unrelated patients, 6, 9, and 14 years of age, with large deletions of the terminal portion of the Bruton tyrosine kinase (Btk) gene extending 4.2,19 kb beyond the 3, end of the gene. The DNA immediately downstream of the 3, end of Btk contains the deafness-dystonia protein gene (DDP). Mutations in this gene have recently been shown to underlie the Mohr,Tranebjaerg syndrome, which is characterized by sensorineural deafness, dystonia, and mental deficiency. Besides the immunodeficiency, our patients exhibited progressive sensorineural deafness. The clue to an associated hearing problem was delayed development of speech in one patient and post-lingual deafness noticed between the age of 3,4 years in the other two. These patients have not yet exhibited significant associated neurologic deficits. [source] Hearing loss in chronic myeloid leukemiaPEDIATRIC BLOOD & CANCER, Issue 1 2005Rahul Naithani MBBS Abstract A 12-year-old girl presented with abdominal pain, fever, and hearing impairment of 6 months duration. She had massive hepatosplenomegaly and anemia. On the basis of her peripheral blood and bone marrow findings, she was diagnosed as chronic myeloid leukemia (CML) in chronic phase. Her hearing was assessed by brainstem evoked responses (BERA), which showed objective improvement in hearing with hydroxyurea. The rare occurrence of deafness in CML is reviewed and possible pathogenesis is discussed. Pediatr Blood Cancer 2005; 45: 54,56. © 2005 Wiley-Liss, Inc. [source] Hearing loss among Ohio farm youth: A comparison to a national sampleAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 3 2009Katherine M. Renick MS Abstract Background Hearing loss is prevalent among adults in the farming community, with some evidence it begins in childhood. Our objective was to compare hearing thresholds of Ohio farm youth to published data on national norms. Methods Baseline data were collected on youth (n,=,212) in 1994,1996 with follow-up (n,=,132) in 2003,2004 including pure-tone air conduction thresholds at 0.5, 1, 2, 3, 4, 6, and 8 kHz. Results When compared to nationally-representative data, study youth had a higher prevalence of hearing loss. The high-frequency range was most affected, particularly at 6 kHz where nearly 50% of the farm youth exhibited some degree of hearing loss at baseline testing. The prevalence of noise-induced threshold shifts, characterized by an audiometric notch, was nearly twice that of the national sample. Conclusions These data suggest that hearing loss, which is common among adult farmers, may be problematic for farm youth as well. Am. J. Ind. Med. 52:233,239, 2009. © 2008 Wiley-Liss, Inc. [source] An assessment of the effects of increased regulatory enforcement and legislative reform on occupational hearing loss workers' compensation claims: Oregon 1984,1998AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 5 2004Brian P. McCall PhD Abstract Background Hearing loss from occupational exposures is a serious and widespread problem. This study measured the outcomes that increased enforcement of regulations and legislative interventions had on hearing loss workers' compensation claims. Methods Workers' compensation claim data from Oregon was analyzed for the period of 1984,1998 to examine trends and severity of hearing loss claims. In 1987 and 1990, Oregon enacted legislative reforms to improve enforcement and promulgation of safety standards in the state. This study examined hearing loss claims between the periods of pre- and post-legislative reforms. Results It was found that hearing loss claims decreased significantly following the legislative reforms, although the average cost per claim increased. Age and tenure effects, and evidence of moral hazard were also discovered. Conclusions Increased enforcement of regulations and legislative interventions by Oregon improved working conditions leading to occupational hearing loss. Nevertheless, hearing loss remains problematic, and continued efforts are required to improve worker safety. Am. J. Ind. Med. 45:417,427, 2004. © 2004 Wiley-Liss, Inc. [source] Predictors of hearing loss in New York farmersAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 1 2001Syni-An Hwang PhD Abstract Background Data from the telephone interview portion of the New York Farm Family Health and Hazard Surveillance were used to study self-reported hearing loss in New York farmers. Methods One thousand six hundred and twenty-two persons completed the hearing loss and noise exposure interview. Hearing loss was defined as at least some trouble hearing in one or both ears. Predictors of hearing loss were determined using logistic regression. Results Twenty-two percent of participants reported hearing loss. From the logistic regression, significant confounders are age (P,=,0.0001), gender (P,=,0.0001), being from a livestock farm (P,=,0.012), and loss of consciousness due to head trauma (P,=,0.04). Significant noise exposures are more hours of lifetime exposure to noisy farm equipment (P,=,0.001) and having had a noisy non-farm job (with some hearing protection P,=,0.002, without any hearing protection P,=,0.0001). Conclusions Farm noise exposure is a serious risk to the hearing of this population. Although use of hearing protection should be encouraged, replacing and modifying farm equipment to decrease noise at the source should be the first priority. Am. J. Ind. Med. 40:23,31, 2001. © 2001 Wiley-Liss, Inc. [source] Auditory function and hearing loss in children and adults with Williams syndrome: Cochlear impairment in individuals with otherwise normal hearing,AMERICAN JOURNAL OF MEDICAL GENETICS, Issue 2 2010Jeffrey A. Marler Abstract Hearing loss is common in school-age individuals with Williams syndrome (WS) and extensive in adults. Prior studies with relatively small sample sizes suggest that hearing loss in WS has an early onset and may be progressive, yet the auditory phenotype and the scope of the hearing loss have not been adequately characterized. We used standard audiometric tools: Otoscopy, tympanometry, air-conduction (bone conduction when available) behavioral testing, and distortion product otoacoustic emissions (DPOAEs) to measure hearing sensitivity and outer hair cell function. We tested 81 individuals with WS aged 5.33,59.50 years. Sixty-three percent of the school-age and 92% of the adult participants had mild to moderately-severe hearing loss. The hearing loss in at least 50% was sensorineural. DPOAE testing corroborated behavioral results. Strikingly, 12 of 14 participants with hearing within normal limits bilaterally had 4,000-Hz DPOAE input/output (DPOAE IO) functions indicative of outer hair cell damage and impaired cochlear compression. Our results indicate that hearing loss is very common in WS. Furthermore, individuals with WS who have "normal" hearing as defined by behavioral thresholds may actually have sub-clinical impairments or undetected cochlear pathology. Our findings suggest outer hair cell dysfunction in otherwise normal hearing individuals. The DPOAE IO in this same group revealed growth functions typically seen in groups with noise-induced damage. Given this pattern of findings, individuals with WS may be at increased risk of noise-induced hearing loss. Recommendations regarding audiological testing for individuals with WS and accommodations for these individuals in both academic and nonacademic settings are provided. © 2010 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||||||||||||||