PROPER USE OF ANTIBIOTICS IN TREATMENT OF ACUTE OTITIS MEDIA

The problem of preventing loss of hearing following acute otitis media has been made more complex by the use of penicillin and other antibiotic agents which may apparently cure yet leave dangerous residual disease. The causes of loss of hearing must be recognized early if remedial treatment is to be effective. In children particularly, loss of hearing may go unnoticed for some time.Physicians who treat otitis media should feel the responsibility not only of bringing an acutely ill child back to health but of preserving the function of the hearing mechanism. Careful examination of the ear after apparent subsidence of infection is mandatory. It is of the utmost importance to be able to recognize the ear drum in its normal state and its various pathological states and to be alert to the early signs of changes associated with loss of hearing. Antibiotics should not be expected to do more than help combat the acute infection in otitis media. Adequate follow-up demands strong suspicion of residual pathologic process in the ear. The prevention of loss of hearing still requires knowledge of the established clinical facts and therapeutic procedures and the application of this knowledge to treatment of acute infections of the middle ear.     

Long-Term Asymmetric Hearing Affects Cochlear Implantation Outcomes Differently in Adults with Pre- and Postlingual Hearing Loss

In many countries, a single cochlear implant is offered as a treatment for a bilateral hearing loss. In cases where there is asymmetry in the amount of sound deprivation between the ears, there is a dilemma in choosing which ear should be implanted. In many clinics, the choice of ear has been guided by an assumption that the reorganisation of the auditory pathways caused by longer duration of deafness in one ear is associated with poorer implantation outcomes for that ear. This assumption, however, is mainly derived from studies of early childhood deafness. This study compared outcomes following implantation of the better or poorer ear in cases of long-term hearing asymmetries. Audiological records of 146 adults with bilateral hearing loss using a single hearing aid were reviewed. The unaided ear had 15 to 72 years of unaided severe to profound hearing loss before unilateral cochlear implantation. 98 received the implant in their long-term sound-deprived ear. A multiple regression analysis was conducted to assess the relative contribution of potential predictors to speech recognition performance after implantation. Duration of bilateral significant hearing loss and the presence of a prelingual hearing loss explained the majority of variance in speech recognition performance following cochlear implantation. For participants with postlingual hearing loss, similar outcomes were obtained by implanting either ear. With prelingual hearing loss, poorer outcomes were obtained when implanting the long-term sound-deprived ear, but the duration of the sound deprivation in the implanted ear did not reliably predict outcomes. Contrary to an apparent clinical consensus, duration of sound deprivation in one ear has limited value in predicting speech recognition outcomes of cochlear implantation in that ear. Outcomes of cochlear implantation are more closely related to the period of time for which the brain is deprived of auditory stimulation from both ears.     

The role of aquaporins in hearing function and dysfunction

The inner ear is composed by tiny and complex structures that, together with peripheral and central auditory pathways, are responsible for hearing processing. However, not only the anatomy of the cochlea, its compartments and related structures are complex. The mechanisms involved in the regulation of homeostasis in the inner ear fluid, which determines the ionic gradient necessary for hearing and balancing sensory excitability, is an intricate phenomenon that involves several molecules. Among them, Aquaporins (AQP) play a significant role in this process. AQP are part of a family of small, integral membrane proteins that regulate different processes, including bidirectional water and ionic flow in the inner ear. Changes in the expression of these proteins are essential to auditory physiology and several pathophysiological processes in the inner ear. This review focuses on the role of AQP in health and disease of the auditory system.     

化脓性中耳炎病原菌感染的研究进展

化脓性中耳炎是耳鼻喉科临床常见疾病,可导致听力下降、鼓膜充血、鼓膜穿孔、耳鸣、耳痛及流脓等。化脓性中耳炎主要由微生物进入中耳引起感染,使中耳黏膜发生化脓性病变,且不同患者感染的病原菌不同。本文从化脓性中耳炎的发病机制、病原菌及其耐药性和治疗方法等几个方面进行综述,以期为临床化脓性中耳炎的诊断及合理用药提供参考。     

HEARING CONSERVATION—Industrial Aspects in California

Impaired hearing is a serious problem. The number of persons with a significant hearing loss has been estimated to be approximately 10 per cent of the population.Hearing loss owing to exposure to noise is becoming an increasingly important disease. Although it has been recognized for more than a century, little if anything was done to prevent it until a few years ago.The initiation of hearing conservation for employees has been undertaken by many of the large companies, particularly in California.Hearing conservation includes preemployment and follow-up hearing tests, control of noise at the source and personal protection (ear plugs, ear muffs).Noise-induced hearing loss is directly related to noise-exposure. Noise must be measured in terms of volume, wave length and length of exposure. Exposure must be analyzed for daily distribution and total time.Although the noise-exposure problem is a serious one, cooperation of employee, employer and the legal and medical professions to initiate preventive programs can reduce it to a minimum.     

Hearing conservation: industrial aspects in California

Impaired hearing is a serious problem. The number of persons with a significant hearing loss has been estimated to be approximately 10 per cent of the population. Hearing loss owing to exposure to noise is becoming an increasingly important disease. Although it has been recognized for more than a century, little if anything was done to prevent it until a few years ago. The initiation of hearing conservation for employees has been undertaken by many of the large companies, particularly in California. Hearing conservation includes preemployment and follow-up hearing tests, control of noise at the source and personal protection (ear plugs, ear muffs).Noise-induced hearing loss is directly related to noise-exposure. Noise must be measured in terms of volume, wave length and length of exposure. Exposure must be analyzed for daily distribution and total time. Although the noise-exposure problem is a serious one, cooperation of employee, employer and the legal and medical professions to initiate preventive programs can reduce it to a minimum.     

先天性小耳畸形手术治疗的研究进展

先天性小耳畸形是发病率较高的头面部畸形之一,常为耳廓及中耳腔同时存在,内耳发育不良相对少见,这一疾病所致的缺陷不仅影响到患者的容貌,更重要的是导致患者听觉功能的障碍,严重影响到患者的日常工作学习和生活。部分患者还伴有或多或少的心理影响,这在双侧小耳畸形的患者中更多见。手术是其主要的治疗方法,要求不仅重建外形正常的耳廓,同时还拥有正常或接近正常的听力。外耳廓再造和听力重建手术不仅使先天性小耳畸形患者的耳部外观明显改善,还能使其听觉功能进一步提高。本文主要综述了先天性小耳畸形的病因和流行病学、分类、手术时机和方式的选择、听力重建、耳廓再造的方法及组织工程学耳再造技术,重点介绍了耳廓再造材料的选择及手术注意点,以期为先天性小耳畸形的临床治疗提供更多理论依据。     

Provision of hearing aids: does specialist assessment cause delay?

OBJECTIVE--To identify the main delay in the provision of hearing aids for people with impaired hearing and identify possible problems and short-comings caused by a community based hearing aid dispensing service. DESIGN--Prospective cohort analysis based on data collected from patients on the duration of hearing impairment, from the referral letters in respect of the general practitioners'' findings on otoscopy, and from the ear, nose, and throat assessment in the clinic with respect to the outcome of specialist otoscopy and management of the hearing impairment. SETTING--General ear, nose, and throat outpatient clinic. PATIENTS--100 Consecutive patients aged 19-94 referred by general practitioners for the provision of hearing aids or for assessment and treatment of impaired hearing. RESULTS--Most patients with impaired hearing did not seek medical advice for at least a year. The time from referral by the general practitioner to the provision of a hearing aid was under two months. General practitioners consistently recognised normality on otoscopy but failed to recognise abnormality in eight of 45 cases. Seven patients required further investigation to exclude serious disease and nine had conditions amenable to surgery. CONCLUSIONS--The main cause of delay in treating impaired hearing is failure by patients to seek help promptly. Specialist assessment of patients with impaired hearing is preferable and does not necessarily cause delay in providing hearing aids. The provision of hearing aids should remain a hospital based service.     

Recent Advances in the Treatment of Deafness

By the utilization of reconstructive procedures (tympanoplasty), middle ear and mastoid infections can be eliminated with the acquisition of a clean, dry ear in about nine out of 10 cases, and hearing can be improved in about half of the patients so treated. Incapacitating attacks of Ménière''s disease can be successfully treated in selected cases by labyrinthectomy, ultrasound destruction of the vestibular system, or streptomycin treatment. With the advent of the transistor, improved power packs and miniaturization, hearing aids have become more acceptable to patients with sensorineural hearing losses. The most successful procedure for the management of otosclerosis is the stapedectomy operation.     

Management of Chronic Middle Ear Effusion

Management of chronic middle ear effusion must center around the reestablishment of normal eustachian tube function. If fluid does not clear with medical management, aspiration becomes necessary. A prosthetic eustachian tube is placed in the tympanic membrane in order to artificially ventilate the middle ear space while primary etiologic factors are being corrected.Unless recurrent or chronic ear disease of this nature is diligently treated, progressive damage may bring about irreversible hearing loss and the potentially dangerous disease, cholesteatoma of the ear.     

Murine CMV-Induced Hearing Loss Is Associated with Inner Ear Inflammation and Loss of Spiral Ganglia Neurons

Congenital human cytomegalovirus (HCMV) occurs in 0.5–1% of live births and approximately 10% of infected infants develop hearing loss. The mechanism(s) of hearing loss remain unknown. We developed a murine model of CMV induced hearing loss in which murine cytomegalovirus (MCMV) infection of newborn mice leads to hematogenous spread of virus to the inner ear, induction of inflammatory responses, and hearing loss. Characteristics of the hearing loss described in infants with congenital HCMV infection were observed including, delayed onset, progressive hearing loss, and unilateral hearing loss in this model and, these characteristics were viral inoculum dependent. Viral antigens were present in the inner ear as were CD3+ mononuclear cells in the spiral ganglion and stria vascularis. Spiral ganglion neuron density was decreased after infection, thus providing a mechanism for hearing loss. The lack of significant inner ear histopathology and persistence of inflammation in cochlea of mice with hearing loss raised the possibility that inflammation was a major component of the mechanism(s) of hearing loss in MCMV infected mice.     

Auditory rehabilitation

Auditory rehabilitation depends of the cause and the severity of the hearing loss (or deafness). Hearing losses dues to middle ear pathologies can beneficiate of medical or surgical treatments, by ossicular prostheses, if it is necessary to restore the function of the ossicles chain. In the sensorineural hearing losses, with inner ear pathology, the use of auditory aid is immediately considered. In the cases for which they are insufficient because of severity of the hearing loss or not suitable because of local non-tolerance, it is possible to use middle ear implant or cochlear implant. The indications of the auditory brainstern implants remain at this day limited to the total bilateral hearing losses due to a complete destruction of cochleae and auditory nerves. These therapeutic orientations are selected after a multidisciplinary evaluation of the deaf person, evaluation that allows the characterization of the hearing loss and its repercussion. In all the cases, the restoration of a bilateral hearing has to be done if possible, making an improvement of the speech comprehension, mainly in the noisy situations, as well as the localization of the sound sources.     

The role of pendrin in the development of the murine inner ear

Enlargement of the vestibular aqueduct (EVA) is a common inner ear malformation found in children with sensorineural hearing loss that is frequently associated with loss-of-function or hypo-function mutations of SLC26A4. SLC26A4 codes for pendrin, which is a protein that is expressed in apical membranes of selected epithelia and functions as an anion exchanger. The comparatively high prevalence of EVA provides a strong imperative to develop rational interventions that delay, ameliorate or prevent hearing loss associated with this phenotype. The development of rational interventions requires a fundamental understanding of the role that pendrin plays in the normal development of hearing, as well as a detailed understanding of the pathobiologic mechanisms that, in the absence of fully functional pendrin, lead to an unstable hearing phenotype, with fluctuating or progressive loss of hearing. This review summarizes studies in mouse models that have focused on delineating the role of pendrin in the physiology of the inner ear and the pathobiology that leads to hearing loss.     

Neuro-rehabilitation Approach for Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSHL) is characterized by acute, idiopathic hearing loss. The estimated incidence rate is 5-30 cases per 100,000 people per year. The causes of SSHL and the mechanisms underlying SSHL currently remain unknown. Based on several hypotheses such as a circulatory disturbance to the cochlea, viral infection, and autoimmune disease, pharmaco-therapeutic approaches have been applied to treat SSHL patients; however, the efficacy of the standard treatment, corticosteroid therapy, is still under debate. Exposure to intense sounds has been shown to cause permanent damage to the auditory system; however, exposure to a moderate level enriched acoustic environment after noise trauma may reduce hearing impairments. Several neuroimaging studies recently suggested that the onset of SSHL induced maladaptive cortical reorganization in the human auditory cortex, and that the degree of cortical reorganization in the acute SSHL phase negatively correlated with the recovery rate from hearing loss. This article reports the development of a novel neuro-rehabilitation approach for SSHL, "constraint-induced sound therapy (CIST)". The aim of the CIST protocol is to prevent or reduce maladaptive cortical reorganization by using an enriched acoustic environment. The canal of the intact ear of SSHL patients is plugged in order to motivate them to actively use the affected ear and thereby prevent progress of maladaptive cortical reorganization. The affected ear is also exposed to music via a headphone for 6 hr per day during hospitalization. The CIST protocol appears to be a safe, easy, inexpensive, and effective treatment for SSHL.     

Effect of hearing AIDS on auditory function in infants with perinatal brain injury and severe hearing loss

Background

Approximately 2–4% of newborns with perinatal risk factors present with hearing loss. Our aim was to analyze the effect of hearing aid use on auditory function evaluated based on otoacoustic emissions (OAEs), auditory brain responses (ABRs) and auditory steady state responses (ASSRs) in infants with perinatal brain injury and profound hearing loss.

Methodology/Principal Findings

A prospective, longitudinal study of auditory function in infants with profound hearing loss. Right side hearing before and after hearing aid use was compared with left side hearing (not stimulated and used as control). All infants were subjected to OAE, ABR and ASSR evaluations before and after hearing aid use. The average ABR threshold decreased from 90.0 to 80.0 dB (p = 0.003) after six months of hearing aid use. In the left ear, which was used as a control, the ABR threshold decreased from 94.6 to 87.6 dB, which was not significant (p>0.05). In addition, the ASSR threshold in the 4000-Hz frequency decreased from 89 dB to 72 dB (p = 0.013) after six months of right ear hearing aid use; the other frequencies in the right ear and all frequencies in the left ear did not show significant differences in any of the measured parameters (p>0.05). OAEs were absent in the baseline test and showed no changes after hearing aid use in the right ear (p>0.05).

Conclusions/Significance

This study provides evidence that early hearing aid use decreases the hearing threshold in ABR and ASSR assessments with no functional modifications in the auditory receptor, as evaluated by OAEs.     

Useless Hearing in Male Emblemasoma auditrix (Diptera,Sarcophagidae) – A Case of Intralocus Sexual Conflict during Evolution of a Complex Sense Organ?

Sensory modalities typically are important for both sexes, although sex-specific functional adaptations may occur frequently. This is true for hearing as well. Consequently, distinct behavioural functions were identified for the different insect hearing systems. Here we describe a first case, where a trait of an evolutionary novelty and a highly specialized hearing organ is adaptive in only one sex. The main function of hearing of the parasitoid fly Emblemasoma auditrix is to locate the host, males of the cicada species Okanagana rimosa, by their calling song. This task is performed by female flies, which deposit larvae into the host. We show that male E. auditrix possess a hearing sense as well. The morphology of the tympanal organ of male E. auditrix is rather similar to the female ear, which is 8% broader than the male ear. In both sexes the physiological hearing threshold is tuned to 5 kHz. Behavioural tests show that males are able to orient towards the host calling song, although phonotaxis often is incomplete. However, despite extensive observations in the field and substantial knowledge of the biology of E. auditrix, no potentially adaptive function of the male auditory sense has been identified. This unique hearing system might represent an intralocus sexual conflict, as the complex sense organ and the behavioural relevant neuronal network is adaptive for only one sex. The correlated evolution of the sense organ in both sexes might impose substantial constraints on the sensory properties of the ear. Similar constraints, although hidden, might also apply to other sensory systems in which behavioural functions differ between sexes.     

Cochlear implants: the view from the brain

The cochlear implant arguably is the most successful neural prosthesis. Studies of the responses of the central auditory system to prosthetic electrical stimulation of the cochlea are revealing the success with which electrical stimulation of a deaf ear can mimic acoustic stimulation of a normal-hearing ear. Understanding of the physiology of central auditory structures can lead to improved restoration of hearing with cochlear implants. In turn, the cochlear implant can be exploited as an experimental tool for examining central hearing mechanisms isolated from the effects of cochlear mechanics and transduction.     

Middle-ear dynamics before and after ossicular replacement

The mechanism of hearing involves conduction of mechanical vibrations along the ossicular chain to the inner ear. An acoustic wave is collected and transformed as it passes down the ear canal and impacts on the tympanic membrane (ear drum). The drum is connected to the inner-ear by three ossicle bones (malleus, incus, and stapes) in a complex arrangement, which serves to further transform the mechanical vibration before it reaches the cochlea of the inner ear. What is the mechanical function of the ossicular chain, and what are the biomechanical consequences of surgical reconstruction with prostheses? To answer these questions, a three-dimensional finite element model of the outer ear canal and middle ear was generated. The dynamical behaviour was predicted for the normal ear, and an ear reconstructed with partial and total ossicular replacement prostheses. For the normal ear, stapes amplitudes of 1x10(-8) m at low frequencies decrease to 4x10(-10)m at approximately 3kHz with several resonance peeks in between, most significantly at approximately 1kHz. Thereafter a further resonance is predicted at 4kHz associated with the ear canal. The behaviour is changed fundamentally by adding a prosthesis; the partial replacement increases the vibratory coupling of the drum and the stapes compared to the normal ear whereas the total replacement does the opposite, and is predicted to have the disadvantage of bringing several new resonances of the ossicular chain into the hearing range. It is hypothesised that the function of the malleus-incus-stapes arrangement is to link the drum to the oval window with the flexibility required for impedance matching but the rigidity to prevent unconstrainable resonances from occurring in the hearing range. If this is true, then the structural stiffness of ossicular chain is the critical design variable for middle-ear replacement prostheses.