Types Of Sensorineural Hearing Loss Research Articles

Evaluation of Pediatric Sensorineural Hearing Loss: A Survey of Pediatric Otolaryngologists

We sought to determine the trends in the evaluation of pediatric patients with sensorineural hearing loss (SNHL) and to determine evaluation patterns based on respondents' demographic data. All members of the American Society of Pediatric Otolaryngology were invited to voluntarily and anonymously complete an online survey. The survey was available from September 2009 to January 2010 and addressed demographic data and tests obtained in evaluating new pediatric patients with SNHL at different age points and with different degrees of hearing loss. The response rate was 22.9% (79 of 345). For all ages and all types of SNHL, the most common consultations were genetics (26% to 76%) and ophthalmology (31% to 66%) consultations. Computed tomography of the temporal bones (49% to 66%), genetic testing (25% to 68%), and electrocardiography (13% to 43%) were the most commonly performed tests. Although there was no consistent difference in practice patterns by gender or years of practice, there were differences in the use of thyroid function tests, TORCH titers, and autoimmune studies by hospital affiliation. Type of SNHL and age are factors in the evaluation of pediatric patients with SNHL. Additionally, evaluation patterns differ according to region and hospital affiliation. The results of this study may provide guidance for otolaryngologists in making information-based and cost-effective evaluations.

Development of Compact Disks in Speech Audiometry and First Stage Verification for the New Speech Materials

Background and Objectives To standard test method of Korean speech audiometry, we developed an audio compact disk, the KsoM-07 (Korean Society of Otolaryngolgy, Monosyllabic, 2007) word lists and evaluated them for clinical usage. Subjects and Method The monitored live voice (MLV) of a female talker was digitally recorded with a Beltone audiometer and the GoldWave program. The calibration for each word was done by calculating the root-mean-square (RMS) at the moving time of 300 ms using (7.0 version, The MathWorks, Inc. Natick, Massachusetts, USA) and the GoldWave (v 5.25 GoldWave Inc. St. John's, NL, Canada) program. The discrimination score was measured in 20 normal subjects to obtain psychometric function curve of each word and to compare the homogeneity of two lists. The first verification methods for new speech materials were done by comparing the discrimination scores of the flat type and the descending types at 150 sensorineural hearing loss with similar pure tone threshold. Results 44% of MLV recording was above dB deviation and had to be recalibrated. Two lists showed equal difficulty or homogeneity in normal subjects. Discrimination scores were statistically different among the groups with respect to hearing level and the slope of audiogram. Conclusion KsoM-07 word lists were relatively homogeneous and showed differences between the descending type and the flat type of hearing loss. Therefore, KsoM-07 word lists can be useful in evaluating the impairment found in the descending type of sensorineural hearing loss as well as in serving as a new speech test material for Korean monosyllabic words.

Value of Genetic Testing in the Otological Approach for Sensorineural Hearing Loss

Sensorineural hearing loss (SNHL) is one of the most common disabilities in human, and genetics is an important aspect for SNHL, especially in children. In recent 10 years, our knowledge in genetic causes of SNHL has made a significant advance, and now it is used for diagnosis and other clinical practices. Hereditary hearing loss can be classified into syndromic and nonsyndromic hearing loss. As the nonsyndromic deafness genes, more than 100 loci for deafness genes have been determined, and more than 40 genes were identified. Furthermore, more than 300 forms of syndromic hearing loss have been characterized, and each syndrome may have several causative genes. In childhood hearing loss, early educational intervention is required in addition to medical intervention for normal development of speech and language. In addition, even severe to profound hearing loss may be restored very effectively by hearing aids or cochlear implants. Because of these features of SNHL, genetic testing has exceptionally high value in the medical practice for hereditary hearing loss. Several strategies are used for genetic testing of SNHL for accurate and efficient identification of the genetic causes, and the results were used for explanation of the cause, prediction of auditory features, prevention of deafness, management of associated symptoms, determination of therapy, and genetic counseling. Identification of damaged cells in the inner ear and the underlying mechanism by genetic testing undoubtedly facilitates development and introduction of novel and specific therapies to distinct types of SNHL.

Functional assessment of allelic variants in the SLC26A4 gene involved in Pendred syndrome and nonsyndromic EVA

Pendred syndrome is an autosomal recessive disorder characterized by sensorineural hearing loss, with malformations of the inner ear, ranging from enlarged vestibular aqueduct (EVA) to Mondini malformation, and deficient iodide organification in the thyroid gland. Nonsyndromic EVA (ns-EVA) is a separate type of sensorineural hearing loss showing normal thyroid function. Both Pendred syndrome and ns-EVA seem to be linked to the malfunction of pendrin (SLC26A4), a membrane transporter able to exchange anions between the cytosol and extracellular fluid. In the past, the pathogenicity of SLC26A4 missense mutations were assumed if the mutations fulfilled two criteria: low incidence of the mutation in the control population and substitution of evolutionary conserved amino acids. Here we show that these criteria are insufficient to make meaningful predictions about the effect of these SLC26A4 variants on the pendrin-induced ion transport. Furthermore, we functionally characterized 10 missense mutations within the SLC26A4 ORF, and consistently found that on the protein level, an addition or omission of a proline or a charged amino acid in the SLC26A4 sequence is detrimental to its function. These types of changes may be adequate for predicting SLC26A4 functionality in the absence of direct functional tests.

Evaluation of Pediatric Sensorineural Hearing Loss With Magnetic Resonance Imaging

To evaluate the incidence and type of intracranial and inner ear abnormalities in children with sensorineural hearing loss (SNHL) identified with magnetic resonance imaging (MRI) and stratified by the degree and type of SNHL. Retrospective review of medical records and MRIs. Tertiary care children's hospital. A total of 227 children aged 1 month to 17 years (mean age, 5.3 years; male to female ratio, 1:1) with a diagnosis of SNHL underwent MRI from June 1,1996, to June 1, 2002. Of these children, 170 had clinical information available and technically adequate MRIs and were included in the study. Magnetic resonance imaging. Identification of an abnormality of the intracranial contents, inner ear, and cochlear nerve. Of the 170 children, 101 (59%) had bilateral SNHL and 69 (41%) had unilateral SNHL, comprising 271 ears with SNHL. Abnormalities of the inner ear were found in 108 ears (40%) with 87 (32%) having abnormalities of the cochlea, which were considered mild in 63 (23%) and moderate to severe in 24 (9%). Forty-nine of 271 ears (18%) with SNHL demonstrated an either absent (26/49 [53%]) or deficient (23/49 [47%]) cochlear nerve. Ears with severe and profound SNHL had more abnormalities than ears with mild and moderate SNHL (66/138 [48%] vs 23/80 [29%]; P = .006), and children having ears with unilateral moderate, severe, or profound SNHL had more inner ear abnormalities than children with bilateral moderate, severe, or profound SNHL (28/45 [62%] vs 54/144 [38%]; P = .004). The overall incidence of inner ear abnormalities in ears of children with SNHL evaluated by MRI is 40%. The most common abnormalities seen were an abnormal cochlea and abnormal cochlear nerve. Children with severe and profound SNHL have a greater percentage of inner ear anomalies than children with mild or moderate SNHL. Children with unilateral hearing loss have a greater percentage of inner ear anomalies than children with bilateral SNHL.

Speech Perception in Noise for Children with Auditory Neuropathy/Dys-Synchrony Type Hearing Loss

To evaluate the effect of background noise on speech perception in children with auditory neuropathy/dys-synchrony (AN/AD) type hearing loss. Open and closed-set speech perception abilities were assessed in 12 school-age children who had been diagnosed with AN/AD in infancy. Data were also obtained from a cohort of subjects with sensorineural (SN) hearing loss and from a group of normal-hearing children. Closed-set speech understanding was more affected by the presence of a competing signal in the hearing impaired than in the normal-hearing subjects. The mean S/N ratio required to identify a spondee in noise was -11.5 +/- 2.0 dB for the normal group, whereas the ratio required for the SN group was -5.4 +/- 5.1 dB and for the AN/AD group was -2.5 +/- 4.7 dB. Closed-set perception in noise was not significantly different for the AN/AD children and their SN counterparts although there was a trend toward poorer performance in the AN/AD group. The effect of background noise on open-set speech perception was also similar across hearing-impaired subjects although again, the AN/AD cohort tended to show greater difficulties in noise than their SN peers. Listening in background noise was more difficult for our group of children with AN/AD-type hearing loss than for their normal-hearing peers. However, the noise effects were not consistent across subjects and some children demonstrated reasonable perceptual ability at low signal-to-noise ratios. The ways in which speech understanding is affected by competing signals may be different for different types of hearing deficit, but the results of this investigation indicate that significant perceptual disruption occurs both in children with auditory neuropathy/dys-synchrony and sensorineural type hearing loss.

Determining the Cause of Hearing Loss: Differential Diagnosis Using a Comparison of Audiometric and Otoacoustic Emission Responses

The purpose of this study was to further investigate the possibility of developing noninvasive methods of differential diagnosis of hearing disorders through the study of experimental animals with induced lesions. In particular, it was desired to compare distortion product otoacoustic emission (DPOAE) responses and auditory brain stem response (ABR) thresholds in Mongolian gerbils having either acoustic or strial damage, using as a reference the same responses measured in a control group of normal young adult gerbils. The goal was to evaluate the potential clinical application of this approach to determining the dominant contribution to sensorineural hearing loss in individual human subjects. DPOAE input-output functions and ABR thresholds were measured over a wide range of stimulus frequencies for three groups: (1) a reference group of normal young adult gerbils; (2) a group in which acoustic damage had been induced 2 wk earlier; (3) a group in which damage to the stria vascularis was induced by a series of furosemide injections. The responses in the experimental groups relative to the normal means were compared to determine which combinations of responses were effective in discriminating between animals with different lesions. Three measures were evaluated in detail: the ABR threshold, the emission threshold at a criterion emission amplitude, and the emission amplitude at a high stimulus level. Considering cases with significant hearing loss (ABR thresholds elevated by 20 dB or more), the best method for distinguishing between the two lesions involved a two-dimensional plot comparing emission and ABR thresholds at the same stimulus frequencies. Acoustic damage cases were found in a broad region where the emission and ABR thresholds were roughly equal, whereas strial damage cases were found in a narrower region where the emission threshold was about 0.4 times the ABR threshold (both in dB). These two cases were compared with a third case introduced by definition, that is, damage to inner hair cell or neural systems resulting in an increase in audiometric threshold but no change in emission responses (e.g., auditory neuropathy). The responses for these three cases were found to lie in different regions of the two-dimensional plot comparing emission and ABR thresholds, provided only that ABR thresholds were elevated 20 dB or more. This diagram also revealed cases of preclinical acoustic damage, in which the ABR threshold was shifted less than 20 dB but where the emission threshold was significantly elevated. The results clearly demonstrate the possibility of developing a clinical method of noninvasive differential diagnosis of hearing loss. The method demonstrated was to add to a standard audiometric evaluation the measurement of DPOAE growth functions over the range of frequencies where these emissions were relatively easy to measure and consistent. The DPOAE stimulus frequencies were chosen to match the audiometric frequencies, and the corresponding emission and audiometric thresholds were compared on a threshold-threshold plot for each individual at a number of stimulus frequencies. Responses in different regions in this plot were found to correspond to different types of sensorineural hearing loss.

High-frequency hearing loss and middle ear involvement in rheumatoid arthritis

Purpose We aimed to evaluate the possible changes in the middle ears of patients with rheumatoid arthritis (RA) and to measure their hearing functions by eleven different test frequencies including standard and high frequencies. Materials and methods The study group was comprised of 74 patients with RA. The control group was comprised of 45 healthy subjects. We performed speech test, tympanometry, acoustic reflex test, and standard and high-frequency pure tone audiometric tests in the study and the control groups. Results It was observed that significant increases in the thresholds of pure tones in all test frequencies for the study group versus the controls ( P <.0001). In terms of the duration of the disease, hearing loss of the patients with disease duration of 1 to 5 years was higher than that of the controls and exceeded beyond the level of 20 dB especially in high frequencies starting from 10,000 Hz. In patients with disease duration of 6 to 10 years, the beginning point for hearing loss was 4,000 Hz. The patients with disease duration of 11 to 15 years and of above 16 years had high hearing thresholds in all frequencies. We found normal pressure in the middle ears of the study and the control groups. Conclusion Sensorineural type hearing loss developed in patients with RA especially in high frequencies. We also determined a diminished compliance in the middle ears of those patients, but this was not in a level of a conducting type hearing loss.

Functional gain of already implanted hearing devices in patients with sensorineural hearing loss of varied origin and extent: Berlin experience.

The evaluation process of patients with sensorineural hearing loss (SNHL) as candidates for an implantable hearing device is a complex matter. Different criteria have to be considered, such as audiologic, psychological, and socioeconomic issues, presently fitted hearing aids, and the patient's satisfaction with hearing aids. The objective of this study was to describe the evaluation process to select candidates for implantation of the Vibrant Soundbridge system (Symphonix Devices, Inc., San Jose, CA, U.S.A.) in a capital area such as Berlin, where approximately 4 million people live. Retrospective chart review with additional clinical and audiologic testing and extensive interview of the patients. The study was conducted at two referral centers. A total of 45,350 pure-tone audiograms (PTAs) and speech audiograms (samples from 1987 to 1999) of patients with different extents and types of SNHL were screened. The PTA, speech audiograms, Abbreviated Profile of Hearing Aid Benefit questionnaire, and a telephone interview served as major criteria. However, several additional criteria in the evaluation and in the decision-making process were included and are described in detail. Of 45,350 patients' charts with their PTA, 346 patients appeared to be possible implant candidates (0.76%) because of their hearing loss. At the time of the hearing screening, 255 patients (0.56%) were possible candidates for the P-type Soundbridge audio processor, and 91 patients (0.2%) were possible candidates for the HF-type processor. Out of the initial 346 patients, 84 (24.3%) were not interested in being further tested or interviewed and declared their lack of interest in the implant technology for several reasons (e.g., satisfaction with their present hearing aid fitting, anxiety to be operated on). A total of 126 patients (36.4%) could be contacted neither by mail nor by telephone. A total of 61 patients (0.13%) declared that they were basically interested, but wanted to wait for further technological refinements (e.g., fully implantable devices). The remaining 75 patients (i.e., 0.16% of the total population screened) could be clinically reevaluated with regard to our standardized protocol. Because of clinical and other reasons, another 33 patients (0.07%) had to be excluded from this study. The resulting 42 patients (0.09%) were undergoing the final ABHAB interview and were ready to be implanted. The number of patients in a stochastic population who are realistic implant candidates for an implantable hearing device is limited. Although there are many more patients suffering from SNHL who meet the requirements of the implant system because of their audiograms, the complexity of a careful evaluation process extremely limits the number of implant candidates. Moreover, reimbursement restrictions in the present health economy worldwide have to be considered.

A Second Gene for Otosclerosis, OTSC2, Maps to Chromosome 7q34-36

Otosclerosis due to abnormal bone homeostasis of the otic capsule is a frequent cause of hearing loss in adults. Usually, the hearing loss is conductive, resulting from fixation of the stapedial footplate, which prevents normal ossicular vibration in response to sound. An additional type of sensorineural hearing loss may be caused by otosclerotic damage to the cochlea. The etiology of the disease is unknown, and both environmental and genetic factors have been implicated. Autosomal dominant inheritance with reduced penetrance has been proposed, but large families are extremely rare. To elucidate the pathogenesis of the disease, identification of the responsible genes is essential. In this study, we completed linkage analysis in a Belgian family in which otosclerosis segregates as an autosomal dominant disease. After excluding linkage to a known locus on chromosome 15 (OTSC1), we found linkage on chromosome 7q, with a multipoint LOD score of 3.54. Analysis of key recombinant individuals maps this otosclerosis locus (OTSC2) to a 16-cM interval on chromosome 7q34-36 between markers D7S495 and D7S2426.

Hearing loss and phacoemulsification

Purpose To determine the acoustic spectra of currently used phacoemulsification units and to contrast phacoemulsification-generated acoustic spectra with representative audiograms of common types of sensorineural hearing loss. Setting Mayo Clinic, Rochester, Minnesota, USA. Methods The acoustic spectra of 3 phacoemulsification systems (Alcon Series 20,000 Legacy, Storz Millennium, and AMO Diplomax) were recorded in an acoustically soundproofed room using a Roland VS-880 Digital Studio Workstation and analyzed with a Hewlett-Packard 35660A Dynamic Signal Analyzer. Results Phacoemulsification handpiece-generated harmonic overtones produced during ultrasound mode (6.0, 12.0, and 18.8 kHz for the 20,000 Legacy and Diplomax; 7.0 and 14.2 kHz for the Millennium) were outside the range of minimal decibel loss in individuals with hearing loss. Supplemental, low-frequency, console-generated tones produced during ultrasound mode (0.4 to 2.0 kHz for the Diplomax; 0.1 to 1.5 kHz for the Millennium) were within the range of minimal decibel loss in individuals with hearing loss. Conclusion Phacoemulsification systems with console-generated, low-frequency tones were audible to ophthalmologists with common types of sensorineural hearing loss.

Measuring the cochlear blood flow and distortion-product otoacoustic emissions during reversible cochlear ischemia: a rabbit model

Impairment to the cochlear blood flow likely induces many types of sensorineural hearing loss. Models using several small laboratory animals have been described in the literature that permit the simultaneous monitoring of the cochlear blood flow with laser-Doppler flowmetry and cochlear function using evoked responses. However, these models have not permitted a direct application of the resulting knowledge to the human condition, primarily due to differences in the translucence of the otic capsule between species. In the present study, to approximate conditions relevant to the human patient, the rabbit was utilized to develop a procedure in which laser-Doppler flowmetry could be used to measure the cochlear blood flow in an animal with an opaque otic capsule. At the same time, the cochlear function was monitored non-invasively using distortion-product otoacoustic emissions. In this manner, a laser-Doppler probe was positioned in the round window niche and the cochlear function measured using distortion-product otoacoustic emissions during a systematic series of ischemic episodes. Cochlear ischemia was produced by deliberately compressing the eighth nerve complex at the porus of the internal acoustic meatus, for periods lasting from 1–3 min, while cochlear blood flow and distortion-product otoacoustic emission measures were obtained simultaneously before, during and following the occlusion. Results demonstrated that the cochlear blood flow sharply decreased within 1 s after compression onset, whereas distortion-product otoacoustic emissions showed obstruction-induced changes after a delay of several seconds, provided that the blood flow decreased, at least, 40%. Similarly, upon release of the compression, the cochlear blood flow began to recover within 1 s, whereas the recovery of the corresponding distortion-product otoacoustic emissions was slightly delayed. Although not apparent in the distortion-product otoacoustic emission recovery time course, the cochlear blood flow consistently overshot its initial baseline value during the recovery process. Thus, although cochlear ischemia produced changes in the distortion-product otoacoustic emission activity that generally followed the resulting alterations in the cochlear blood flow, the detailed relationship between the two measures was complex.

Interleukin-2 Affects Cochlear Function Gradually but Reversibly

Interleukin-2 (IL-2), one of the chemical mediators produced by helper T cells, activates its target cells via its receptor and induces inflammatory reactions indirectly. In this study, IL-2 was instilled into the round window niche of rats and the electrophysiological effects of inflammation on the inner ear were evaluated by a frequency-specific auditory brainstem response (ABR) technique. ABR threshold curves and intensity-latency (I-L) curves were investigated. In most cases, moderate sensorineural hearing loss (SNHL) was observed in the high-frequency areas (16–31.5 kHz). In the time course investigation of I-L curves, the responses of SNHL type appeared only 1 day after instillation (day 1) gradually becoming more prominent, to become most pronounced on days 5–7. The electrophysiological impairment was reversible within 2 weeks. Differing degrees of responsiveness of effusion production were observed following the instillation of IL-2, varying from pronounced middle ear effusion causing rather severe mixed hearing loss, to complete lack of effusion. Inflammation induced by IL-2 affects cochlear function gradually but reversibly.

Sensorineural hearing deficit: a systematic approach based on imaging findings.

Sensorineural hearing loss (SNHL) can be classified audiometrically into two varieties: sensory (cochlear) and neural (retrocochlear). Individuals with sensory SNHL have damage to the "end organ" (the cochlea) at a macroscopic or microscopic level. When present, imaging manifestations may involve the bony labyrinth or membranous labyrinth. Abnormalities of the bony labyrinth are demonstrable primarily with computed tomography and include demineralization, congenital deformities, traumatic lesions, and erosive or destructive lesions. Abnormalities of the membranous labyrinth include enhancement and hemorrhage, which are demonstrable with magnetic resonance (MR) imaging, and obliteration, which may be diagnosed with either modality. Individuals with neural (retrocochlear) SNHL have involvement of the remainder of the auditory pathway exclusive of the cochlea. This type of SNHL requires study of the internal auditory canal, cerebellopontine angle, brain stem, thalamus, and temporal lobe. The entirety of this type of examination is best performed with high-resolution MR imaging in virtually all cases.

心因性難聴に対する簡易スクリーニング法

An easy screening method for psychogenic hearing loss was developed using an air conduction pure-tone audiometer.We performed pure-tone audiometry using 7 continuous and 7 interrupted pure tones from 125Hz to 8000Hz, and then compared differences in the thresholds of hearing in 13 patients with psychogenic hearing loss. Eleven out of 13 patients (85%) showed an improvement in their thresholds in over 4 out of 7 tones when stimulated by a continuous pure tone in one ear or both ears.On the other hand, the other 73 sensorineural hearing loss patients showed no such improvements in their thresholds by a continuous pure tone.These results suggest that this method of comparing the threshold of continuous and interrupted pure tones may easily differentiate psychogenic hearing loss from other types of sensorineural hearing loss. When improvements in the hearing threshold are observed by this method, psychogenic hearing loss should be suspected. Bekesy audiometry and auditory evoked brain stem responses should be performed for an accurate diagnosis.

Electrocochleography in syphilitic hearing loss.

Syphilitic labyrinthitis presents such symptoms as hearing loss, tinnitus, vertigo and/or dizziness, and is well known as one of the endolymphatic hydropic diseases. In order to elucidate the relationship between syphilitic hydrops and ECochG findings, we performed ECochG in patients with syphilis following our previously reported study of patients with Meniere's disease. Twenty-two patients who have been serologically and clinically diagnosed as having syphilitic labyrinthitis were examined with ECochG between December, 1982 and November, 1991. Of the 27 ears tested with ECochG, 2 showed no response due to severe hearing loss, and increased SP (SP/AP ratio > 0.37) was observed in 14 (56.0%) out of the remaining 25 ears. The SP/AP ratio of patients with syphilitic labyrinthitis was not significantly different from that of the patients with Meniere's disease or delayed endolymphatic hydrops, while it was significantly higher than that of the patients with sudden deafness and other types of sensorineural hearing loss. We conclude that the electrocochleographic features of endolymphatic syphilitic lesions resemble those in Meniere's disease.

Patterns of hearing loss and psychiatric morbidity in elderly patients attending a hearing clinic

AbstractThis study examines the relationship between hearing loss and psychiatric diagnosis in a geriatric population attending a hearing clinic. Major depression was the most frequent psychiatric disorder and was diagnosed in 30% of subjects. A sensorineural type hearing loss was diagnosed in 85% of the depressed subjects. More hearing loss was seen in subjects with onset of depression after age 55 years, in comparison to geriatric patients with depression onset before age 55 years, subjects with other psychiatric disorders and subjects without a psychiatric diagnosis (p &lt;0.001). The audiogram and speech audiometry suggest involvement of auditory nerve and central auditory pathways in late onset depression.

A Clinical Study of Electrocochleography in Meniere's Disease

Electrocochleography (ECochG) of 168 ears with definite Meniere's disease was studied. The results were compared with recordings from 29 normal ears and 444 ears with other types of sensorineural hearing loss. It is shown that the SP/AP ratio is much more useful than SP amplitude for detecting endolymphatic hydrops. There was little difference in the mean values of SP/AP from those proposed by many other investigators; the mean values all being near 0.25. From 0.30 to 0.40 of SP/AP was considered adequate as the upper limit. Following intravenous administration of glycerol, a significant decrease in SP/AP was found in 21 Meniere's ears. However, there was no change of SP/AP after oral administration of glycerol and isosorbide. This difference may be due to the fact that a larger oral than intravenous administration is necessary to affect SP/AP. Although a postoperative decrease of 10% or more in SP/AP was observed in 5 patients, 10 patients followed up for 2 years or more after surgery did not show a statistically significant change of SP/AP and pure tone threshold. ECochG should be repeatedly recorded to be useful as a monitor for the presence of hydrops. It is discussed whether biochemical or mechanical changes in endolymph may cause a decrease in SP/AP after the use of dehydrating agents and endolymphatic sac surgery.

突発性難聴の治療成績 特に予後に関する要因について

Idiopathic sudden hearing loss is a type of sensorineural hearing loss that is said to be treatable or may respond to some empirical therapeutic measures in many, but not all, patients, although its etiology is still not precisely known.This report is based on 105 patients with unilateral sudden hearing loss treated in Yamanashi medical college for 6 years since October, 1983, with special emphasis on the prognostic features in the symptomatology.A statistical analysis of the clinical data from these cases revealed important prognostic indicators to be: the time from the onset to the initial visit and start of treatment, the severity of the initial hearing loss, the hearing loss configuration on the audiogram and age. Other factors closely related to the prognosis of the disorder included recovery of hearing during the first one week after the initial treatment, the severity of vertigo, the degree of hearing in the opposite ear, etc.The literature on idiopathic sudden hearing loss is reviewed and the results of 6 years of experience are presented. Since the natural history of idiopathic sudden hearing loss is highly variable, possibly because its pathogenesis is multifactorial, we consider that additional statistical study of the disorder is necessary.

内耳局所水分代謝異常が原因と思われたレルモワイエ症候群の一症例

A 62-year-old female presented with vertigo, tinnitus, sensation of fullness and fluctuating hearing loss of sensorineural type on the left ear. Thirteen years after, the vestibular symptoms disappeared naturally, but the cochlear symptoms are still present. Dehydration therapy, such as the oral administration of iso-sorbid or the intra-venous injection of furosemide aggravated the cochlear symptoms while overhydration therapy improved them. The results of the dehydration and hydration tests evaluated by hearing level were opposite to those frequently observed in patients with endolymphatic hydrops.Therefore, we assume that occlusion of the reuniens duct or utriculo-endolymphatic valve and endolymphatic collapse in the cochlea were responsible for the characteristic course of the symptoms in our patient.