Degree Of Sensorineural Hearing Loss Research Articles

Reliability of electric response audiometry using 80 Hz auditory steady-state responses

The reliability of the Auditory Steady State Response (ASSR) has not been thoroughly evaluated despite its recent application as a clinical tool for threshold estimation. The purpose of this study was to examine test-retest (TR) reliability of ASSR threshold estimates in an empirical research design. The ASSR, tested using modulation frequencies approximately 80 Hz and above, was evaluated against pure tone audiometry (PTA), and the slow vertex potential (SVP, N1-P2). Sixteen normal-hearing young female adults were tested twice, one week apart. Varying degrees of sensorineural hearing loss of a notched configuration were simulated with filtered masking noise. Test-retest reliability was assessed using Pearson-product moment correlation analysis, supplemented by other post-hoc analyses. Results demonstrated moderately strong TR reliability for ASSR at 1000, 2000 and 4000 Hz (r = 0.83–0.93); however, the reliability of ASSR at 500 Hz was weaker (r = 0.75). Results suggest that ASSR-ERA is a reliable test at mid–high frequencies, at least with the configuration and degrees of simulated sensorineural hearing loss examined in this study.

Factors Associated With Sensorineural Hearing Loss Among Survivors of Extracorporeal Membrane Oxygenation Therapy

To endeavor to explain why some graduates of extracorporeal membrane oxygenation (ECMO) therapy develop sensorineural hearing loss (SNHL) whereas others do not, to study the variability seen in the degree of SNHL, to attempt to explain why some graduates with SNHL experience progressive worsening whereas others do not, and to describe the time course of the onset of SNHL on the basis of identified risk factors. A retrospective chart review with proportional-hazards regression analysis to identify specific risk factors for SNHL from a list of patient and treatment variables. Children's Hospital Boston, a pediatric tertiary-care facility and ECMO center. Neonatal ECMO graduates born in 1986-1994 who survived to discharge and underwent audiologic evaluations (n = 111) and a random sample of ECMO graduates who survived to discharge and did not undergo audiologic evaluations (n = 30). Audiologic data, including the presence or absence of SNHL, the severity of SNHL at the most recent evaluation, the stability or progressive worsening of hearing (with the first evaluation compared with the most recent evaluation), and the occurrence of delayed-onset SNHL. Twenty-nine (26%) of 111 ECMO graduates who underwent audiologic testing had SNHL at the last evaluation. Of these 29 subjects with SNHL, 21 (72%) had progressive SNHL, of whom 14 (48%) had delayed-onset SNHL. The age of identification of SNHL ranged from 4 months to 8 years 11 months. Factors identified with proportional-hazards regression analyses as being associated significantly with the time to onset of SNHL were a primary diagnosis of congenital diaphragmatic hernia (hazard ratio: 2.60), length of ECMO therapy (hazard ratio: 7.18), and number of days children received aminoglycoside antibiotics (hazard ratio: 5.56). Kaplan-Meier "time-to-event" curves were constructed to illustrate the time course of onset of SNHL, as affected by each of the variables identified as significant risk factors. These findings illustrate the need for early, routine, audiologic evaluations throughout childhood for all ECMO graduates. Children at even greater risk for developing SNHL because of a history of congenital diaphragmatic hernia, prolonged ECMO therapy, and/or a lengthy course of aminoglycoside antibiotic therapy should be monitored even more closely throughout childhood, depending on the child's individual risk indicators, as suggested here. On the basis of these risk indicators, efforts can be made to minimize the risk of hearing loss while a child is being treated with ECMO. In addition, these risk indicators can assist with counseling families of ECMO graduates regarding the child's specific risk of developing SNHL and how it can be managed should it occur.

Cochlear implantation for post-irradiation deafness

Irradiation to the head and neck area can lead to various possible otological complications. Nasopharyngeal carcinoma (NPC), being a prevalent disease in Hong Kong and Southern China, is the commonest indication for irradiation that we have encountered leading to such complications. Conventional radiotherapy for NPC, with one anterior facial field and two lateral opposing facial fields, subject both temporal bones to significant irradiation. Occasionally, a profound degree of sensorineural hearing loss necessitates the consideration of cochlear implantation for hearing rehabilitation. This paper summarizes our experience and results of cochlear implantation for a series of patients who had developed profound deafness subsequent to radiotherapy for treatment for NPC.

Revisiting loudness measures in children using a computer method of cross-modality matching (CMM).

The test efficiency and reliability of loudness assessment using a computer-controlled method of cross-modality matching (CMM) between line length and loudness was investigated in children 4 to 12 years with normal hearing or mild to severe degrees of sensorineural hearing loss. Adult listeners with normal hearing served as a comparison group. Computer-generated visual and acoustic stimuli were used to derive individual loudness data. Children and adults with normal hearing presented with similar loudness functions, while children with sensorineural hearing loss had steeper functions than their normal-hearing counterparts. Retest data supported reliability of the CMM method with children within the current study and between previous studies performed with a similar, but manual, method. The computer CMM approach proved more time efficient than the manual one, halving the test time. The CMM loudness task in a computerized version may have potential in a research or clinical setting, in particular for individualizing hearing aid fittings with children.

Otologics middle ear transducer™ ossicular stimulator: Performance results with varying degrees of sensorineural hearing loss

ObjectivesThis study was conducted to demonstrate the safety and efficacy of the Otologics Middle Ear Transducer™ (MET™) Ossicular Stimulator and, in particular, to compare the audiologic benefits of this novel form of electromechanical stimulation with those of conventional acoustical amplification. Material and MethodsA total of 282 patients were implanted with the device in Europe and the USA. Pure-tone audiometry, speech recognition and subjective assessment of benefit were tested before the surgery and 2, 3, 6 and 12 months afterwards. The US patients were fitted with a digital hearing aid for a minimum of 4 weeks prior to surgery, and the same benefit measures were performed with the digital hearing aid and their “walk-in” hearing aid. ResultsGroup mean postoperative bone and air conduction thresholds did not change significantly from preoperative levels. Postoperative air conduction thresholds decreased slightly in some individual patients, due to the mass loading effect exerted by the transducer on the ossicles. Sufficient gain was available to reach target prescription levels for moderate to severely impaired hearing individuals. Speech and subjective assessment of patient preference indicated that patients did as well or better with the MET Ossicular Stimulator than with their “walk-in” aid or the standardized digital aid. Conclusion The capability of the MET Ossicular Stimulator to provide appropriate gain as a function of degree of hearing loss indicates that the device is a viable treatment for moderate to severe sensorineural hearing loss in adults.

Selective vestibular ablation by intratympanic gentamicin in patients with unilateral active ménière's disease: a prospective, double-blind, placebo-controlled, randomized clinical trial

ObjectiveTo establish the efficacy of intratympanic gentamicin treatment in patients with unilateral Ménière's disease.Material and MethodsThis was a prospective, double-blind, randomized clinical trial of intratympanic gentamicin versus intratympanic buffer solution (placebo) in patients with established active Ménière's disease in the affected ear. Outcome measures included the number of vertiginous spells, degree of sensorineural hearing loss, labyrinthine function and labyrinthine asymmetry.ResultsTopical gentamicin provided a significant reduction in the number of vertiginous spells, although a “placebo effect” was also observed. Sensorineural hearing loss did not occur in the gentamicin group, although some deterioration occurred in the placebo group.ConclusionsIntratympanic gentamicin is a safe and efficient treatment for the vertiginous spells associated with Ménière's disease. When applied early in the course of the disease, it may prevent some of the sensorineural hearing deterioration associated with it.

Effect of Thiopental Sodium on Hearing Outcomes Following Microvascular Decompression Surgery

Background: The use of intraoperative brainstem auditory evoked potential (BAEP) has reduced the incidence of sensorineural hearing loss (SNHL) after microvascular decompression (MVD). This complication occurs due to direct compressive and/or stretching injury of the cochlear nerve or to indirect compression of the perineural vasculature during cerebellar retraction. The aim of this study was to evaluate the effect of thiopental sodium on SNHL after MVD for hemifacial spasm. Methods: 94 hemifacial spasm patients with normal hearing function preoperatively and who underwent MVD under intraoperative BAEP monitoring were enrolled in this study. Patients were randomly divided into two groups. 52 patients were administered placebo (control group) and 42 patients were administered thiopental sodium 5 mg/kg intravenously 5 minutes before cerebellar retraction (thiopental group). The effects of thiopental on intraoperative BAEP changes and postoperative hearing functional outcomes were sought. Incidence and degree of postoperative SNHL were evaluated by pure tone audiometry threshold analysis. Results: Maximal changes in intraoperative BAEP parameters did not differ between the two groups, and neither did the incidence nor degree of SNHL. In the control group, 4 transient and 4 permanent postoperative SNHL, including 2 deaf patients, occurred with an overall incidence of 15.4%. In the thiopental group, 2 transient and 1 permanent postoperative SNHL occurred, with an overall incidence of 7.1%. Conclusions: Thiopental sodium administered prior to cerebellar retraction might reduce the incidence of postoperative hearing loss.

Enlarged vestibular aqueduct syndrome in the pediatric population.

To correlate clinical and audiometric findings with the radiologic appearance in patients with enlarged vestibular aqueduct.DESIGN A retrospective review of data from enlarged vestibular aqueduct patients identified in a pediatric hearing-impaired database of 1,200 patients. SETTING A tertiary care pediatric referral center. Subjects were included for study with a radiographic diagnosis of enlarged vestibular aqueducts in at least one ear by a pediatric neuroradiologist. Audiometric evaluations and radiographic temporal bone measurements. Seventy-seven patients were identified with an enlarged vestibular aqueduct with a male-to-female ratio of 1:1.5. Patients were followed for a mean of 34 months (range, 0-179 months). Hearing loss was bilateral in 87% of cases. Vestibular symptoms were present in only three (4%) of the patients. Three patients (4%) suffered a sudden decrease in hearing after mild head trauma. Borderline enlargement of the vestibular aqueduct was associated with varying degrees of sensorineural hearing loss. Ninety-seven percent (64 of 66) of ears in control subjects with no sensorineural hearing loss had normal vestibular aqueduct measurements at the midpoint and operculum. Overall, the audiogram remained stable in 51% of ears, fluctuated in 28%, and progressively worsened in 21%. Measurements of the vestibular aqueduct at the midpoint and the operculum did not correlate with the audiometric threshold or the audiogram configuration. However, mean vestibular aqueduct size at the operculum was significantly larger in those with a progressive loss when compared with those with a fluctuating or stable hearing outcome. Overall, audiometric thresholds remained generally stable, with sudden deterioration of hearing after head trauma seen in only three male patients. Progression of hearing loss after head trauma was not a significant finding in our patient population. Vestibular aqueduct opercular size alone showed a direct correlation with the audiometric outcome. Borderline enlarged vestibular aqueduct measurements appear to be associated with sensorineural hearing loss.

Relationship of retinopathy and hearing loss in type 2 diabetes mellitus

This study investigated whether the degree of diabetic retinopathy correlates with degree of sensorineural hearing loss. Seventy-five diabetic patients and 45 sex- and age-matched healthy controls were evaluated audiologically. Patients were classified into groups by severity of retinopathy: group 1 (n=28), no retinopathy, group 2 (n=4), background retinopathy; and group 3 (n=23), proliferative or end-stage retinopathy. Diabetics had a statistically significant difference at all frequencies of hearing loss, as compared with controls.

Prediction of Hearing Threshold in Infants Using Auditory Steady-State Evoked Potentials

This retrospective study examines the relationship between auditory steady-state evoked potential (ASSEP) thresholds determined in infancy and subsequently obtained behavioral hearing levels in children with normal hearing or varying degrees of sensorineural hearing loss. Overall, the results from 211 subjects showed that the two test techniques were highly correlated, with Pearson r values exceeding .95 at each of the audiometric test frequencies between 500 and 4000 Hz. Analysis of the findings for babies with significant hearing loss (moderate to profound levels) showed similar threshold relationships to those obtained in previous studies involving adults and older children. The results for infants with normal or near-normal hearing did, however, differ from those reported for older subjects, with behavioral thresholds typically 10 to 15 dB better than would have been predicted from their ASSEP levels.

Pediatric cochlear implantation in auditory neuropathy.

Auditory neuropathy (AN) is characterized by varying degrees of sensorineural hearing loss, an absent or severely abnormal auditory brainstem response, and normal otoacoustic emissions. The nomenclature for this condition reflects the concept that the site of lesion is proximal to the cochlea (e.g., cochlear nerve). Given this hypothesis, it is reasonable to expect limited benefit from cochlear implantation in patients with AN. However, a growing body of evidence shows the striking benefits of cochlear implantation in AN. To explore this topic, we reviewed our population of children with AN and, specifically, the performance results in those children having undergone cochlear implantation. A retrospective case review of those patients diagnosed with AN from 1993 to 2001. A tertiary pediatric referral center. A diagnosis of AN reported from the Center for Hearing and Deafness Research, Cincinnati, OH, database. Eighteen patients were diagnosed with AN (11 girls, 7 boys), with 3 sets of siblings, including 1 set of identical twins. Four patients with AN underwent implantation in the previous 5 years. Twelve out of the 18 patients had classic risk factors for AN (e.g., prematurity and hyperbilirubinemia). The degree of hearing loss varied in our patients, with a majority showing severe to profound deficits. All children with implants showed improvement in auditory and verbal development, but this improvement was variable. The success of cochlear implantation in these patients suggests that some children with AN have an auditory system lesion that can be compensated for by cochlear implantation. This implies either an inner hair cell or inner hair cell-cochlear nerve junctional pathology that can be overcome by direct electrical stimulation.

Hearing Loss Evaluation of Sjo¨gren's Syndrome Using Distortion Product Otoacoustic Emissions

Sjögren's syndrome (SS) is a cell-mediated immune disorder primarily affecting the exocrine glands and hearing loss may be the first otological manifestation of this autoimmune disease. In order to assess the degree of sensorineural hearing loss in SS, 22 female patients were examined by means of standard audiometric tests (pure-tone audiometry, acoustic reflexes and impedance testing) and using distortion product otoacoustic emissions (DPOAEs). The results indicated that only 36.3% of the patients had mild sensorineural hearing loss. Hearing level and distortion product threshold estimates were found to be significantly correlated. No relationship was found between the duration of the disease and the DPOAE and hearing threshold variables. The data suggest that SS may not directly cause sensorineural hearing loss.

Spectrum of Mutations in USH2A in British Patients with Usher Syndrome Type II

Usher syndrome (USH) is a combination of a progressive pigmentary retinopathy, indistinguishable from retinitis pigmentosa, and some degree of sensorineural hearing loss. USH can be subdivided in Usher type I (USHI), type II (USHII) and type III (USHIII), all of which are inherited as autosomal recessive traits. The three subtypes are genetically heterogeneous, with six loci so far identified for USHI, three for USHII and only one for USHIII. Mutations in a novel gene, USH2A, encoding the protein usherin, have recently been shown to be associated with USHII. The gene encodes a protein with partial sequence homology to both laminin epidermal growth factor and fibronectin motifs. We analysed 35 British and one Pakistani Usher type II families with at least one affected member, for sequence changes in the 20 translated exons of the USH2A gene, using heteroduplex analysis and sequencing. Probable disease-causing mutations inUSH2A were identified in 15 of 36 (41.7%) Usher II families. The most frequently encountered mutation (11/15 families or 11/18 mutated alleles) was del2299G in exon 13, resulting in a frameshift and premature stop codon. Other mutations include insertions and point mutations, of which two are previously unreported. Five different polymorphisms were also detected. Our results indicate that mutations in this gene are responsible for disease in a large proportion of British Usher type II patients. Moreover, if screening for mutations in USH2A is considered, it is sensible to screen for the del2299G mutation first.

Noise-induced hearing loss: the effect of melanin in the stria vascularis

Conflicting investigations regarding the potential protective effect of melanin against noise-induced sensorineural hearing loss have suggested that eumelanin and pheomelanin may have differing effects within the stria vascularis. Three strains of C57BL/ 6J mice, (+/+, a/ a) wild-types (dark coats/black eyes), ( c2j/ c2j, a/ a), albinos (white coats/pink eyes), and (+/+, Ay/ Ay) yellow mice (yellow coats/black eyes), were subjected to five consecutive days of broad band noise exposure at 112 dB(A) SPL for 3 h/day. Cochlear function was evaluated with auditory brainstem response audiometry to pure tones immediately pre-exposure, 5–6 h post-exposure, and 14 days post-exposure. No significant difference in the degree of sensorineural hearing loss induced in the three strains of mice was identified. The eumelanin and pheomelanin content of each stria vascularis and amount of protein per stria for both mouse and guinea pig ( 2/ NCR) were determined via high performance liquid chromatography. No pheomelanin was found in the stria of yellow mice, suggesting that coat color is not an accurate predictor of strial melanin content. The melanin content per mg of strial protein was higher in mice than in guinea pigs. A species-specific difference in melanin content does not explain the absence of a protective effect in mice.

遅発性内リンパ水腫について 特にメニエール病との関連

Delayed endolymphatic hydrops (DEH), a disease entity that can be differentiated from Meniere's disease, typically develops in patients who have experienced a profound, long-term hearing loss in one ear. This condition was first reported by Kamei et al. ('71), who indicated that it occurred in about 20% of patients who had had unilateral profound deafness since early childhood (UPDC), and it appeared at various stages of adulthood, during or after puberty. Wolfson and Leiberman ('75) and Nadol et al. ('75) reported other types of unilateral profound deafness causing this condition that were due to viral and bacterial labyrinthitis, head trauma, or sudden deafness. Schuknecht ('78) defined DEH and classified it into two types: the ipsilateral type, in which vestibular symptoms identical to the vestibular symptoms of Meniere's disease develop in a previously deafened ear, and the contralateral type, in which a fluctuating hearing loss and/or vestibular symptoms develop in the hearing ear. The underlying pathophysiologic mechanism for the development of DEH has been explained as progressive endolymphatic hydrops in the inner ear due to delayed atrophy or fibrous obliteration of the endolymphatic resorption system, resulting from a previous inner-ear injury. In the ipsilateral type, episodic vertigo is not usually accompanied by fluctuating hearing levels and tinnitus because the hearing loss is profound. The period between the onset of pre-existent deafness in one ear and the onset of DEH ranges from several months to 74 years. The cause of the pre-existent deafness is UPDC in more than half of the cases of both types of DEH. Almost all kinds of other degenerative disorders of the inner ear are mostly due to inflammation (viral and bacterial) and trauma (physical and acoustic). The ipsilateral type of DEH is more frequently seen than the contralateral type. The onset age of the contralateral type is higher, in general, than that of the ipsilateral type. Medical treatment may be effective for both types of DEH. Complete relief from episodic recurrent vertigo may be expected in 65% of cases within 5 years after the onset of vertigo and in 90% of cases within 10 years. Labyrinthectomy or vestibular nerve section in the deaf ear is curative in the ipsilateral type, but no satisfactory surgical therapy is available for the contralateral type of the disease. The audiological definition of DEH by Schuknecht seems, however, to be somewhat arbitrary, as the patients' symptoms form a continuous spectrum with other Meniere's syndrome cases, occurring in association with less-marked degrees of sensorineural hearing loss. The existence of the contralateral type of DEH due to UPDC, which often shows typical symptoms of Meniere's disease, seems to suggest that Meniere's disease may occur as a delayed sequela of subclinical damage of the inner ear, especially damage sustained in childhood.

Maternally inherited nonsyndromic hearing loss.

In this study we characterized clinically and evaluated molecularly a large family with maternally inherited hearing impairment. Relatives were evaluated audiologically and clinically, the most likely pattern of inheritance was deduced, and molecular DNA analysis for the known mitochondrial mutations associated with hearing impairment was performed. Clinical examination of several relatives showed a normal general state of health, but in 14 of the members tested variable degrees of sensorineural hearing loss were noted. The pedigree was established and demonstrated a clear pattern of maternal inheritance, with 34 of 38 offspring of deaf mothers being hearing impaired, but none of 22 offspring of deaf fathers having any hearing impairment. Since by far the most likely explanation of such a maternal inheritance pattern is a mitochondrial mutation, molecular testing for the three known mitochondrial mutations, A1555G, A7445G, and Cins7472, was performed on 27 of the relatives. All of the individuals tested had the normal sequence at the sites tested. This family with nonsyndromic sensorineural hearing loss has an inheritance pattern strongly suggestive of a mitochondrial mutation. However, molecular testing for the three known mitochondrial mutations associated with nonsyndromic hearing impairment was negative, implying that additional molecular defects can lead to the same phenotype. The search for this novel molecular defect is underway.

The Effect of Hemodialysis on Hearing Using Pure-Tone Audiometry and Distortion-Product Otoacoustic Emissions

Patients under treatment of hemodialysis (HD) frequently exhibit some degree of sensorineural hearing loss. Fifteen subjects and 10 controls were tested by using pure-tone audiometry (PTA) and distortion-product otoacoustic emissions (DPOAEs) before and after a HD treatment. Other parameters (blood pressure, body weight, blood chemistries) were also evaluated before and after HD: The purpose of this study was to determine the acute effect of HD on hearing level by measuring PTA and DPOAE before and after one HD session. The results from PTA and DPOAE testings showed that hearing was unaffected by HD. However, all 15 subjects revealed significantly poorer hearing, especially in the higher frequencies, compared to that of the controls (p < 0.0001). It was concluded then that HD is a safe treatment, and that the sensorineural hearing loss in these patients may be attributed to the preexisting renal disease.

Aging and high-frequency hearing sensitivity.

As part of a large population-based study of hearing and aging, ultra high-frequency (9-20 kHz) threshold measures are reported for 3396 participants grouped by age (48-59 years, n = 1233; 60-69 years, n = 1031; 70-79 years, n = 851; 80-92 years, n = 281). Ultra high-frequency (UHF) thresholds were higher for older age groups. The percentage of unmeasurable responses also was significantly higher for older age groups and for higher frequencies in the UHF range. The observed age effects remained significant after adjusting for gender. In general, UHF thresholds were significantly higher for men compared to those for women at lower UHF frequencies (9-14 kHz), but were not significantly different by gender for the highest UHF frequencies (16, 18, and 20 kHz). After accounting for hearing loss at traditional audiometric frequencies (250-8000 Hz), the age effect still remained; even for comparable degrees of sensorineural hearing loss, participants in older age groups evidenced higher UHF thresholds.

Delayed endolymphatic hydrops: clinical manifestations and treatment outcome

The clinical entity of delayed endolymphatic hydrops was first defined by Schuknecht in 1978. It constitutes the development of symptoms consistent with endolymphatic hydrops either ipsilateral or contralateral to an ear with a profound hearing loss. We report our experience with this condition amongst 394 patients with Meniére's syndrome followed prospectively. Of 24 patients with the ipsilateral condition, nearly half responded to medical treatment. Thirteen patients underwent vestibular nerve section and the outcome, as assessed by a disability grading system, was very satisfactory. The proportion of patients undergoing vestibular nerve section (54.9%) was substantially higher than patients with classical Meniére's syndrome during the same period (5.4%) reflecting the increased severity of the symptoms. The contralateral form was less frequently seen and patients were more refractory to treatment. The audiological definition of delayed endolymphatic hydrops appears somewhat arbitrary, as these patients form a continuous spectrum with other Meniére's syndrome cases, occurring in association with less marked degrees of sensorineural hearing loss.

Evaluation of a Wide Range of AmplitudeFrequency Responses for the Hearing Impaired

The long-term average frequency spectrum of speech was modified to 25 target frequency spectra in order to determine the effect of each of these spectra on speech intelligibility in noise and on sound quality. Speech intelligibility was evaluated using the test as developed by Plomp and Mimpen (1979), whereas sound quality was examined through judgments of loudness, sharpness, clearness, and pleasantness of speech fragments. Subjects had different degrees of sensorineural hearing loss and sloping audiograms, but not all of them were hearing aid users. The 25 frequency spectra were defined such that the entire dynamic range of each listener, from 5 dB above threshold to 5 dB below UCL, was covered. Frequency shaping of the speech was carried out on-line by means of Finite Impulse Response (FIR) filters. The tests on speech reception in noise indicated that the Speech-Reception Thresholds (SRTs) did not differ significantly for the majority of spectra. Spectra with high levels, especially at low frequencies (probably causing significant upward spread of masking), and also those with steep negative slopes resulted in significantly higher SRTs. Sound quality judgments led to conclusions virtually identical to those from the SRT data: frequency spectra with an unacceptably low sound quality were in most of the cases significantly worse on the SRT test as well. Because the SRT did not vary significantly among the majority of frequency spectra, it was concluded that a wide range of spectra between the threshold and UCL levels of listeners with hearing losses is suitable for the presentation of speech energy. This is very useful in everyday listening, where the frequency spectrum of speech may vary considerably.