Persistent Sensorineural Hearing Loss Research Articles

Generation of human otic neuronal organoids using pluripotent stem cells.

Otic neurons, also known as spiral ganglion neurons (SGNs) in mammalian cochlea, transmit electrical signals from sensory hair cells to cochlear nuclei of the auditory system. SGNs are sensitive to toxic insults, vulnerable to get irreversible damaged and hardly regenerate after damage, causing persistent sensorineural hearing loss. Yet, to get authentic SGNs for research or therapeutic purpose remains challenging. Here we developed a protocol to generate human otic neuronal organoids (hONOs) from human pluripotent stem cells (hESCs), in which hESCs were step-wisely induced to SGNs of the corresponding stages according to their developmental trajectory. The hONOs were enriched for SGN-like cells at early stage, and for both neurons and astrocytes, Schwann cells or supporting cells thereafter. In these hONOs, we also determined the existence of typical Type I and Type II SGNs. Mature hONOs (at differentiation Day 60) formed neural network, featured by giant depolarizing potential (GDP)-like events and rosette-organized regions-elicited calcium traces. Electrophysiological analysis confirmed the existence of glutamate-responsive neurons in these hONOs. The otic neuronal organoids generated in this study provide an ideal model to study SGNs and related disorders, facilitating therapeutic development for sensorineural hearing loss.

Hearing Instability in Children with Congenital Cytomegalovirus: Evidence and Neural Consequences.

Sensorineural hearing loss (SNHL) is a common sequela of congenital cytomegalovirus (cCMV), potentially exacerbating neurocognitive delay. The objectives of this study were to assess: (1) age at which SNHL in children with cCMV; (2) stimulability of the auditory system in children with cCMV following cochlear implantation (CI); and (3) whether features of magnetic resonance imaging (MRI) potentially are predictive of hearing outcomes. In this retrospective study of a prospectively acquired cohort, 123 children with cCMV who were referred for hearing loss at a single tertiary referral hospital over 20 years were compared with an unmatched comparative group of 90 children with GJB2-related deafness. Outcome measures were results of newborn hearing screening (NHS), behavioral audiograms, and, in a subgroup of cochlear implant (CI) users, responses from the auditory nerve and brainstem evoked by CI at initial activation, as well as lesional volume of FLAIR-hyperintense signal alterations on MRI. All but 3 of 123 children with cCMV had confirmed and persistent SNHL. At birth, 113 children with cCMV underwent NHS, 31 (27%) passed in both ears and 23 (20%) passed in one ear (no NHS data in 10 children). At the first audiologic assessment, 32 of 123 (26%) had normal hearing bilaterally; 35 of 123 (28%) had unilateral SNHL; and 57 of 123 (46%) had bilateral SNHL. More than half (67 of 123, 54%) experienced hearing deterioration in at least one ear. Survival analyses suggested that 60% of children who developed SNHL did so by 2.5 years and 80% by 5 years. In the children who passed NHS in one or both ears, 50% developed hearing loss by 3.5 years in the ear, which passed unilaterally (n=23 ears), and 50% by 5 years in bilateral passes (n=62 ears). Hearing loss was significant enough in all but one child with isolated high-frequency loss for rehabilitation to be indicated. Hearing thresholds in individual ears were in the CI range in 83% (102 of 123), although duration of deafness was sufficient to preclude implantation at our center in 13 children with unilateral SNHL. Hearing aids were indicated in 16% (20 of 123). Responses from the auditory nerve and brainstem to initial CI stimulation were similar in children with cCMV-related SNHL compared with GJB2-related SNHL. Characteristic white matter changes on MRI were seen in all children with cCMV-related SNHL (n=91), but the lesion volume in each cortical hemisphere did not predict degree of SNHL. cCMV-related SNHL is often not detected by NHS but occurs with high prevalence in early childhood. Electrophysiological measures suggest equivalent stimulability of the auditory nerve and brainstem with CI in children with cCMV and GJB2-related SNHL. Hyperintense white matter lesions on FLAIR MRI are consistently present in children with cCMV-related SNHL but cannot be used to predict its time course or degree. Combined, the data show early and rapid deterioration of hearing in children with cCMV-related SNHL with potential for good CI outcomes if SNHL is identified and managed without delay. Findings support universal newborn screening for cCMV followed by careful audiological monitoring. 3 Laryngoscope, 132:S1-S24, 2022.

PATHOLOGICAL CHANGES IN THE INNER EAR IN EXPERIMENTAL MODELING OF SENSORINEURAL HEARING LOSS IN ANIMALS

Aim. Study of pathological changes in the inner ear in the modeling of sensorineural hearing loss in laboratory animals.Materials and methods. A pilot study involving 27 laboratory animals − white outbred rats – was conducted. Modeling of sensorineural hearing loss was conducted by exposing them for 10 days to broadband noise of 90 dB, vibration and simultaneous immobilization of laboratory animals divided into 3 groups according to exposure conditions. The development of hearing loss was confirmed by the results of the registration of delayed caused emissions and emissions at the frequency of distortion products. After removing rats from the experiment histological medication from animals cochlear was produced and they were studied by the method of light microscopy.Results. In animals exposed to noise and vibration effects on the background of immobilization, the formation of persistent sensorineural hearing loss was achieved, which was confirmed by objective registration of violations of auditory function, and also by the results of morphological study of cochlear of the temporal bones of animals. More pronounced histological changes were noted in animals exposed to noise and vibration on the background of immobilization compared with the group of rats which were exposed only to noise impact and immobilization without applying vibration. Dystrophic and destructive changes in the structures of the spiral organ, signs of apoptotic way of cell death in the inner ear were detected. In addition, pronounced changes occurred in the spiral ganglia.Conclusion. Modeling of sensorineural hearing loss in laboratory animals on the basis of noise and vibration exposure in terms of immobilization leads to the formation of persistent sensorineural hearing loss, as evidenced by functional and morphological methods. Pathological changes in the inner ear show themselves through dystrophic and destructive changes in the spiral organ, including apoptosis of cells, and especially in the spiral ganglia. The use of this noise-vibration model of hearing loss can be a promising basis for future studies of drugs for the treatment of sensorineural hearing loss.

THE PROBLEM OF OCCUPATIONAL HEARING LOSS IN AIRCREWS OF CIVIL AVIATION

The article discusses the actual problem of professional hearing loss in members of the flight professions of civil aviation in Russia. The indices of this disease amounted of one-third of the prevalence rate values concerning occupational diseases of the hearing organ among all workers of “noise” professions, are registered with the highest frequency in pilots and aircraft commanders and have no tendency to decrease. As the only occupational disease among the persons of the flight professions of the main airlines of the Russian Federation, the persistent sensorineural hearing loss has not only medical but also socio-economic aspects. It is registered in working-age persons lost their professional aptitude. The main revealed causes of the gain of indices of the hearing loss in professional pilots are: the insufficient qualification of medical workers on the issues of early diagnosis of the negative impact of noise on the hearing organ; the lack of regulated criteria for the diagnosis and examination of the relationship between the hearing loss and the occupation; insufficiently clear algorithms of departmental logistics in the examination of occupational diseases of the hearing organ. The ways of optimization of the problem are shown as follows: the development and implementation of the method of speech perception in the conditions of competing the in-cab noise of the aircraft; objective criteria for decision-making on admission/non-admission to the flight work; adequate assessment of the indices of the in-cab noise and sound pressure arising in the aircraft headset during speech radio exchange; mandatory compliance with the requirements of accounting for the data of the Protocol of acoustic load for the entire period of the flight activity, with the indication of noise-protective characteristics of the used airguns in the implementation of the examination of the communication of the disease of the hearing with the profession.

Sudden Sensorineural Hearing Loss after Orthopedic Surgery under Combined Spinal and Epidural Anesthesia.

Postoperative hearing loss following nonotologic surgery is rare. For patients undergoing subarachnoid anesthesia, the loss of cerebral spinal fluid and hence the drop in intracranial pressure can result in hearing loss and cranial nerve palsy. We report a case in which a patient sustained orthopedic surgery under combined spinal and epidural anesthesia complicated by severe and persistent sensorineural hearing loss. This report is a reminder that postoperative sudden sensorineural hearing loss is a poorly understood complication. A high index of suspicion is required for early diagnosis of this complication, although prompt treatment does not guarantee a good outcome.

Atypical Cogan’s Syndrome: A Case Report

Cogan’s Syndrome is a rare autoimmune disease that presents with multi-system involvement including the eyes and ears. It is typically characterized by attacks of vertigo resembling Meniere, sensorineural hearing loss and interstitial keratitis. Ocular findings may vary widely, other than interstitial keratitis in the manner of atypical form which is less frequently seen and has a less favourable prognosis. Here, a 52-year-old male patient with atypical Cogan’s Syndrome is reported. In Cogan’s Syndrome, especially if diagnosis is delayed, hearing diminishes progressively and deafness usually occurs despite therapy, while ocular findings usually respond to topical therapy and persistent blindness does not occur. Persistent sensorineural hearing loss can be prevented by early diagnosis and immediate high dose systemic steroid administration with other immunosuppressive agents if required.

Sensorineural Hearing Loss

Kawasaki disease (KD) is an acute systemic vasculitis of unknown etiology in which the main complication is coronary arteritis. Sensorineural hearing loss (SNHL) has also been described as a complication of this disorder. The objective of this study was to evaluate the prevalence of SNHL in patients with KD and to determine the possible causative abnormality, correlating the findings with the prevalence of cardiac complications, with the use of gammaglobulin, and with the results of laboratory tests. A clinical cohort of 40 patients with KD seen between 2005 and 2007 was evaluated by acoustic immittance measurement and brainstem-evoked response audiometry that were performed within the first 30 days of disease and 6 months after the first evaluation. Patients with hearing disability after this period underwent further testing through otoacoustic emissions analysis. All patients were treated with intravenous administration of immunoglobulin. Ten (25%) of the 40 patients developed coronary aneurysm, and 22 (55%) disclosed hearing loss within the first 30 days, although this problem was noticed by the parents in only 3 children. In 12 (30%), the hearing loss persisted after 6 months. Ten (83.3%) of these 12 patients also showed thrombocytosis (platelets, >500,000), 8 (66%) had anemia (hemoglobin, <10 mg/dL), and all had high erythrocyte sedimentation rate (>50 mm/hr) persisting more than 30 days. SNHL was more prevalent than coronary complications. A significant association was found between persistent SNHL, although often not initially noted, with a prolonged presence of thrombocytosis, anemia, and high erythrocyte sedimentation rate and the delayed use of intravenous administration of immunoglobulin after the first 10 days of illness.

Hearing and vestibular loss in Streptococcus suis infection from swine and traditional raw pork exposure in northern Thailand

To describe a series of 40 culture-proven, Streptococcus suis infected patients, focusing on route of entry and on hearing and vestibular dysfunction. Retrospective study of patient records in a tertiary care hospital in northern Thailand, 2003-2007. The majority (75 per cent) of cases were men with heavy drinking habits. A past history of the consumption of raw pork and/or pig's blood was found in 62.5 per cent of cases, whereas contact with swine products was found in 25 per cent. Thirty patients presented with sepsis, 19 with meningitis and 10 with infective endocarditis. The overall mortality rate was 20 per cent. After a mean follow up of 17 months, 73 per cent of the surviving meningitis cases had persistent sensorineural hearing loss and 50 per cent demonstrated vestibular impairment. In one patient, roentgenographic studies of the temporal bone were compatible with labyrinthitis ossificans. Permanent hearing loss and vestibular impairment occur frequently in persons surviving meningitis caused by Streptococcus suis.

Sensorineural Hearing Loss After Treatment of Nasopharyngeal Carcinoma: A Longitudinal Analysis

To analyze the effects of radiotherapy (RT) and chemotherapy in relation to sensorineural hearing loss (SNHL) after contemporary treatment of nasopharyngeal carcinoma. A total of 87 nasopharyngeal carcinoma patients were treated with RT or chemoradiotherapy using either three-dimensional conformal RT or intensity-modulated RT between 2004 and 2005. Tympanometry and pure-tone audiogram assessments were performed before treatment and then serially at 6-month intervals. The dose-volume data of the cochlea were analyzed. The effects of cisplatin administered in concurrent and nonconcurrent phases was explored. Of the 170 eligible ears, RT (n = 30) and chemoradiotherapy (n = 140) resulted in 40% (n = 12) and 56.4% (n = 79) persistent SNHL (> or = 15 dB loss), respectively, after a median follow-up of 2 years. SNHL at a high frequency was more frequent statistically in the chemoradiotherapy group than in the RT-alone group (55% vs. 33.3%, p < 0.01), but not at a low frequency (7.9% vs. 16.7%, p = 0.14). Within the chemoradiotherapy group, the mean cochlea dose and concurrent cisplatin dose were important determinants of high-frequency SNHL, with an odds ratio of 1.07/Gy increase (p = 0.01) and an odds ratio of 1.008/mg/m(2) increase (p < 0.01), respectively. Age, gender, and nonconcurrent cisplatin dose were not statistically significant factors. A mean radiation dose to the cochlea of <47 Gy would result in <15% of patients developing severe (> or = 30 dB) high-frequency SNHL. The results of our study have shown that high-frequency SNHL is significantly related to the mean cochlea dose and the concurrent cisplatin dose. A mean dose constraint of 47 Gy to the cochlea is recommended to minimize SNHL after chemoradiotherapy.

Protective Efect of Brain-derived Neurotrophic Factor Against the Ototoxicity of Pseudomonas aeruginosa Exotoxin A

Objective--The protective effect of brain-derived neurotrophic factor (BDNF) against the ototoxicity resulting from exposure of Pseudomonas aeruginosa exotoxin A (PaExoA) to the middle ear was analyzed. The combined effect of BDNF and NG-nitro-L-arginine methyl ester (L-NAME) was also investigated. Material and methods--Six groups of albino rats were instilled through the tympanic membrane into the round window niche with the following solutions: saline; PaExoA; BDNF; L-NAME; PaExoA + BDNF; and PaExoA + BDNF + L-NAME. Frequency-specific (2-31.5 kHz) auditory brainstem responses were used to obtain the hearing thresholds before and 2, 5 and 15 days after instillation. Results--PaExoA penetrated from the middle ear into the cochlea, causing initially mixed hearing loss, followed by persistent sensorineural hearing loss. This impairment was blocked by BDNF at 6, 8 and 10 kHz on Day 2 and at 8 kHz on Day 5. L-NAME given in combination with BDNF did not show any additional protective effect. There were no significant differences in the thickness of the round window membrane between control ears and those in each instillation group. Conclusion--Our results suggest that BDNF may protect against cochlear damage caused by PaExoA in the middle turns of the ear.

Sensorineural hearing loss and Kawasaki disease: A prospective study

Purpose: Kawasaki disease (KD) is an acute, self-limited vasculitis of infants and children that is now the most common cause of acquired heart disease in the pediatric age group in the United States and Japan. Reports have documented the association of acute KD with sensorineural hearing loss. To assess the prevalence of hearing loss following acute KD in a geographically and ethnically diverse population, a prospective, multicenter study of hearing loss in patients with KD was conducted. Materials and Methods: Patients with acute KD were enrolled in 7 clinical centers and underwent a primary audiologic evaluation within 30 days of the onset of fever. Patients were subsequently reevaluated after resolution of the acute phase of the disease. A questionnaire assessing risk factors for hearing loss was also administered. Results: A total of 62 patients were evaluated during the 29-month study period. At the first audiologic evaluation, 19 patients (30.6%) had sensorineural hearing loss, 6 patients (9.7%) had conductive hearing loss, 17 patients (27.4%) had normal hearing, and 20 patients (32.3%) had inconclusive studies. Overall, 2 of 36 patients (5.5%) had sensorineural hearing loss documented on their second audiologic evaluation. No risk factors for hearing loss were identified by the questionnaire. Conclusions: Transient sensorineural hearing loss (20 to 35 dB) is a frequent complication of acute KD and may be related to salicylate toxicity in some patients. Persistent sensorineural hearing loss is uncommon. Parents and primary care providers should be made aware of the potential for persistent sensorineural hearing loss following resolution of KD, but routine audiologic screening of this patient population does not appear to be warranted. (Am J Otolaryngol 2001;22:343-348. Copyright © 2001 by W.B. Saunders Company)

Traumatic perilymphatic fistulas in children: etiology, diagnosis and management

Post-traumatic perilymphatic fistulas have been described following ear and temporal bone injury, particularly in the setting of temporal bone fractures. However, indications for exploratory surgery in cases of trauma without temporal bone fracture are vague and not well described. We describe three children who presented with symptoms suggestive of perilymphatic fistula (PLF) without an associated temporal bone fracture: two with penetrating tympanic membrane injuries and one with blunt temporal bone trauma. All had symptoms of hearing loss and vestibular disturbance. Two of the children cooperated with ear-specific audiologic assessment, which demonstrated sensorineural hearing loss (SNHL) on the traumatized side. The third child showed audiometric evidence of a SNHL on the injured side, but due to his age, the degree of severity of the SNHL was unable to be appropriately addressed prior to the patient being surgically managed. All three children underwent exploratory surgery and were found to have bony defects in the region of the oval window. All were repaired with fascial grafts to the oval and round windows with complete resolution of vestibular symptoms. However, two of the three patients with documented post-operative audiograms suffered from persistent SNHL on the injured side. We conclude that exploratory middle ear surgery is indicated in patients suffering from blunt or penetrating temporal bone or middle ear trauma who demonstrate persistent vestibular symptoms, sensorineural hearing loss or radiographic evidence of oval window pathology. As this is a limited number of patients, a larger series may be warranted to study the actual incidence of post-traumatic PLF in the child with persistent hearing loss and vertigo after head or ear trauma.

Acceptance of wearing hearing aids by children: a longitudinal analysis

There exist no systematic longitudinal studies concerning the acceptance of hearing aids in Germany. This study examines the acceptance of a hearing aid (defined by its daily/weekly use) in the management of children with persistent sensorineural hearing loss over a period of years. 35 children with monaural or binaural hearing loss were treated with a hearing aid. All children had at least a 25-dB averaged mid-frequency pure-tone hearing loss (500, 1000, 2000, 4000 Hz). The data consist of standardized parent ratings at 4 points in time over a period of nearly 30 months. Unilateral-impaired children wore their hearing aids less often than bilateral-impaired children. This effect was not significant at the beginning (P = 0.85) but increased over time. By the end the difference was significant (P = 0.004). Mild to moderate monaural hearing-impaired children accepted their hearing aids, whereas children with severe to profound hearing loss refused to wear them. Bilateral hearing-impaired children demonstrated, a priori, a better wearing acceptance that even improved with time. There was never a significant difference between boys and girls in their average wearing time. A significant correlation of age and wearing acceptance was also not observed at any time. Hearing aids are an effective treatment with high acceptance and compliance, especially by children with bilateral sensorineural hearing loss. The quality of acceptance of monaural hearing-impaired children needs to be studied further.

Surgical treatment of auditory canal exostoses

Although complications of surgical removal of external auditory canal exostoses are rare, reported surgical complications include tympanic membrane perforation, postoperative hearing loss, canal stenosis, and facial nerve injuries. We report on our experience in exostosis surgery, consisting of 59 procedures in 48 patients. Preoperative and postoperative complaints and findings, intraoperative complications, and audiologic results are described and discussed. There has been a minimum of one year of follow-up in every case. Postoperative canal stenosis was seen in 2 cases of preoperative severe persistent external otitis. Temporary threshold shift was recorded in 6 patients. Persistent sensorineural hearing loss occurred in 4 patients. Six of the 10 patients with temporary or persistent hearing loss had already shown preoperative sensorineural hearing loss. Intraoperatively tympanic membrane perforation occurred in 3 cases, accidental opening of the mastoid in 1 case. Exostosis surgery should be reserved for uninfected ear canals. Meatal skin preservation without circular meatal flap incision is recommended to avoid postoperative canal stenosis. Especially in cases of preexisting sensorineural hearing loss, attention should be focused on the intraoperative noise reduction by tympanic membrane protection and pauses of noise exposition.

Sensorineural hearing loss in patients treated for nasopharyngeal carcinoma: A prospective study of the effect of radiation and cisplatin treatment

The pattern of sensorineural hearing loss (SNHL) after primary treatment for nasopharyngeal carcinoma (NPC) was studied, and the effect of cisplatin, radiotherapy does, and fractionation were evaluated. One hundred thirty-two patients, 227 ears, and 1100 audiogram reports were analyzed. Radiotherapy dose ranged from 59.5 to 76.5 Gy. Fifty-two patients received preirradiation cisplatin, total dose 100-185 mg/m(2). Serial postirradiation bone conduction thresholds at 0.5 kHz, 1 kHz, 2 kHz, and 4 kHz were compared with pretreatment thresholds at respective frequencies. Increase of at least 15 dB was considered as significant and was further grouped as transient or persistent SNHL. Univariate and multivariate analyses were performed to identify predicting factors for persistent SNHL. At median follow-up of 30 months, 24.2% of ears developed persistent SNHL. High frequency was more affected than low frequencies, 22 vs. 5.3%. Males were more affected than females, 29.4 vs. 15.5%, p = 0.0132. Incidence of persistent SNHL increased with age, with 0, 17.2, and 37.4% of patients aged under 30, between 30-50 and over 50 affected, respectively, p = 0.0001. High incidence was found in patient with postirradiation serous otitis media (SOM), 46.9%. Chemotherapy with cisplatin and radiation dose or fractionation had no significant effect. Multivariate analysis confirmed age, sex, and postirradiation SOM as significant prognostic factors for persistent SNHL. Transient and persistent SNHL occurred after radiotherapy, more commonly affecting high frequency. A low dose of preirradiation cisplatin did not increase the risk. A dose fractionation effect of radiotherapy was not confirmed in this study.

Bacterial meningitis: pathogenesis, pathophysiology, and progress.

FIFTY years after the advent of antibiotics for clinical use, bacterial meningitis remains an important cause of morbidity and mortality. As such, it represents a unique human infectious disease, because the pathophysiologic effects of disease progression and suboptimal outcomes occur despite bacteriologic cure of the infection.1 Specifically, the mortality rate for adults who have Streptococcus pneumoniae meningitis remains 20 to 30 percent,2 , 3 with neurologic morbidity affecting half of survivors.4 The incidence of persistent sensorineural hearing loss in children who survive bacterial meningitis is 10 percent (31 percent of those with S. pneumoniae are affected) — a finding with critical implications . . .

Bacterial Meningitis and Hearing Impairment: A Prospective Study

The purpose of this study is to demonstrate the incidence and the pattern of post-meningitis hearing impairment. A prospective study of 68 meningitis patients was performed. The patients' hearing was evaluated immediately following acute illness and periodically checked for two years. The incidences of the initial sensorineural and conductive deafness were 26.4% and 20.6%, respectively. Two patients (3%) suffered from mixed deafness. No consistent audiometric pattern was found in the cases of sensorineural hearing loss. Serial hearing evaluations demonstrated complete recovery of all cases of conductive hearing loss with only a slight improvement in the low tones noted in one patient with sensorineural hearing loss. No late development of sensorineural loss has occurred.

Toy weapons and firecrackers: a source of hearing loss.

Although acoustic injury as a result of exposure to noisy toys and firecrackers has been reported previously, most of these studies have been conducted on adults. The purpose of this prospective study, conducted at the time of Deepawali, an Indian festival of fireworks, was two-fold: 1. to measure the acoustic output of representative samples of toy weapons and firecrackers and the intensity level at critical spectator points from the site of emission; and 2. to determine the auditory status of a cross section of the target population, involving 600 participants from various age groups, before and after exposure to firecracker noise at Deepawali. The average sound level at a distance of 3 m was 150 dB, thus exceeding the damage risk criterion for adults (i.e., 130 dB peak level). An average 30 dB persistent sensorineural hearing loss was found in 2.5% of the target population as a result of toy weapon/firecracker noise during Deepawali. The 9- to 15-year-old age group was most affected. A judicious approach in the manufacture and use of toy weapons and firecrackers, in addition to legal restraints, is advocated.

Auditory disorders following head injury in children.

199 children with blunt head injury were examined. Eighteen fractures of the temporal bone were found, two of which were transverse. In both cases the damaged ear remained completely deaf. Of the 16 longitudinal fracture patients, one was left with a persistent 27 dB conductive hearing loss. In another, surgery revealed fractures of the stapedial crura. Persistent sensorineural hearing loss (greater than or equal to 30 dB) at high frequencies (4 to 8 kHz) was observed in 7% of patients. The results of the audiological tests led to the conclusion that sensorineural hearing loss in association with head injury is generally located in the inner ear. The auditory sequelae after head injury in children were found to be similar to those reported earlier in adults.

Inner ear barotrauma.

To the Editor.—Freeman and Edmonds reported five cases of Inner Ear Barotrauma. In each case persistent sensorineural hearing loss followed diving episodes. All five patients were trained Navy divers with preincident and postincident audiograms. The authors point out clearly that in none of the cases could the ear lesion be attributed to decompression sickness or to pulmonary barotrauma. Thus, nitrogen embolization has been ruled out by the authors as a possible etiologic factor. All five divers had difficulty in performing Valsalva maneuvers on the affected side, but in only one case was there otoscopic evidence of middle ear involvement. In several cases vestibular symptoms were also present. The hearing losses were either immediate or delayed by a number of hours. Barotrauma seems a likely etiologic factor and inner ear barotrauma is a reasonable descriptive term. In the discussion of mechanisms, the authors discuss the possible effect of pressure