Inner ear decompression sickness after a routine dive and recompression chamber drill.

Inner ear decompression sickness (IEDCS) is an uncommon diving-related injury affecting the vestibulocochlear system, with symptoms typically including vertigo, tinnitus, and hearing loss, either in isolation or combination. Classically associated with deep, mixed-gas diving, more recent case series have shown that IEDCS is indeed possible after seemingly innocuous recreational dives, and there has been one previous report of IEDCS following routine hyperbaric chamber operations. The presence of right-to-left shunt (RLS), dehydration, and increases in intrathoracic pressure have been identified as risk factors for IEDCS, and previous studies have shown a predominance of vestibular rather than cochlear symptoms, with a preference for lateralization to the right side. Most importantly, rapid identification and initiation of recompression treatment are critical to preventing long-term or permanent inner ear deficits. This case of a U.S. Navy (USN) diver with previously unidentified RLS reemphasizes the potential for IEDCS following uncomplicated diving and recompression chamber operations - only the second reported instance of the latter.

[Features of otosurgery in children after blast injuries]. / Osobennosti rekonstruktivnoi otokhirurgii u detei posle minno-vzryvnykh ranenii.

An explosion is a process that rapidly releases a huge amount of energy in the form of heat, kinetic energy, and high-pressure shock waves. Since the organ of hearing is most susceptible to pressure changes, damage to the sound-conducting or sound-receiving systems is inevitable in case of an explosive injury. This article examines the mechanism of formation of explosive injuries of the middle and inner ear in children and adolescents, the features of diagnosis and tactics of surgical reconstructive treatment of explosive ear injuries based on the data available in the scientific literature and their own experience.

Trauma-induced vestibular dysfunction: Possible functional repair under α1-antitrypsin-rich conditions.

Transient vestibular organ deafferentation, such that is caused by traumatic tissue injury, is presently addressed by corticosteroid therapy. However, restoration of neurophysiological properties is rarely achieved. Here, it was hypothesized that the tissue-protective attributes of α1-antityrpsin (AAT) may promote restoration of neuronal function. Inner ear injury was inflicted by unilateral labyrinthotomy in wild-type mice and in mice overexpressing human AAT. A 2-week-long assessment of vestibular signs followed. All animals responded with peak vestibular dysfunction scores within 4 h after local trauma. While wild-type animals displayed partial or no recovery across 7 days post-injury, AAT-rich group exhibited early recovery: from behavioral score 9-out-of-9 at peak to 4.8 ±â€¯0.44 (mean ±â€¯SD) within 8 h from injury, a time when wild-type mice scored 8.6 ±â€¯0.54 (p < 0.0001), and from vestibular score 15-out-of-15 to 7.8 ±â€¯2.2 within 24 h, when wild-type mice scored 13.0 ±â€¯2.0 (p < 0.01). Thus, recovery and functional normalisation of an injured vestibular compartment is achievable without corticosteroid therapy; expedited tissue repair processes appear to result from elevated circulating AAT levels. This study lays the foundation for exploring the molecular and cellular mediators of AAT within the repair processes of the delicate microscopic structures of the vestibular end organ.

Radiological evaluation of inner ear trauma after cochlear implant surgery by cone beam CT(CBCT).

PURPOSE: Cochlear implantation (CI) has been extended to involve younger age group with higher incidence of residual hearing which increases the need of minimizing surgical inner ear trauma. Radiological evaluation for electrode position has been studied yet without assessment of inner ear trauma, our objective is radiological evaluation of post cochlear implantation inner ear trauma MATERIAL AND METHODS: 20 patients with CI for pre lingual SNHL were included in this study. Cone beam CT (CBCT) was used for evaluation of electrode position and assessment of inner ear trauma. A Neuroradiologist and an implant surgeon analyzed the relation of inserted electrode to the intra-cochlear structures, with introduction of novel radiological grading for inner ear trauma. RESULTS: The mean major cochlear diameter was 8.9 mm, the mean angular depth of insertion was 406.9944 (SD = 165.0559). Ten patients were with no cochlear trauma (grade 0), three patients were grade 1, two patients were grade 2 and five patients were grade 3 inner ear trauma. CONCLUSION: Radiological evaluation for electrode position should extend to involve assessment of inner ear trauma using relation of the implant to cochlear internal structures which could be performed by CBCT with high resolution and least metallic artifacts.

Inner Ear Damage by Firecracker Trauma.

Firecrackers are still popular among the general public of various populations worldwide. This study investigated inner ear damage in patients with firecracker trauma and analyzed noise levels in 6 kinds of commercially available firecrackers. During the past 20 years, we have experienced 30 patients with firecracker trauma. An inner ear test battery comprising audiometry, cervical and ocular vestibular-evoked myogenic potential (cVEMP and oVEMP) tests and a caloric test was performed. The real-time noise levels were measured outdoors at a distance of 2, 4 and 6 m away from a lighting firecracker to mimic a noise event. Mean hearing levels at high frequencies (4,000 and 8,000 Hz) were significantly higher than those at the low and middle frequencies, indicating that firecrackers mostly cause high-tone hearing loss. For the vestibular damage, abnormality percentages were higher in the results of cVEMP (80%) and oVEMP (60%) tests, but not in the caloric test (8%). In conclusion, most firecrackers exhibited noise levels > 110 dB SPL even at a distance of 6 m. This blast injury simultaneously damaged the cochlea, saccule and utricle, but spared the semicircular canals, indicating that blast exposure potentiates the adverse effect of noise exposure on both cochlear and vestibular partitions.

Diving medicine.

Exposure to the undersea environment has unique effects on normal physiology and can result in unique disorders that require an understanding of the effects of pressure and inert gas supersaturation on organ function and knowledge of the appropriate therapies, which can include recompression in a hyperbaric chamber. The effects of Boyle's law result in changes in volume of gas-containing spaces when exposed to the increased pressure underwater. These effects can cause middle ear and sinus injury and lung barotrauma due to lung overexpansion during ascent from depth. Disorders related to diving have unique presentations, and an understanding of the high-pressure environment is needed to properly diagnose and manage these disorders. Breathing compressed air underwater results in increased dissolved inert gas in tissues and organs. On ascent after a diving exposure, the dissolved gas can achieve a supersaturated state and can form gas bubbles in blood and tissues, with resulting tissue and organ damage. Decompression sickness can involve the musculoskeletal system, skin, inner ear, brain, and spinal cord, with characteristic signs and symptoms. Usual therapy is recompression in a hyperbaric chamber following well-established protocols. Many recreational diving candidates seek medical clearance for diving, and healthcare providers must be knowledgeable of the environmental exposure and its effects on physiologic function to properly assess individuals for fitness to dive. This review provides a basis for understanding the diving environment and its accompanying disorders and provides a basis for assessment of fitness for diving.

Trauma-associated tinnitus.

BACKGROUND: Up to 53% of individuals suffering from traumatic brain injuries develop tinnitus. OBJECTIVE: To review the current literature on trauma-associated tinnitus in order to provide orientation for the clinical management of patients with trauma-associated tinnitus. MATERIALS: A systematic literature search has been conducted in PubMed database applying the search terms posttraumatic tinnitus and trauma-associated tinnitus. Results have been complemented by related studies, book chapters, and the authors' clinical experience. RESULTS: Not only mechanical, pressure-related, or noise-related head traumata but also neck injuries and emotional trauma can cause tinnitus. Exact diagnosis is essential. Disorders such as ossicular chain disruption, traumatic eardrum perforation, or perilymphatic fistula can be surgically treated. It should also be considered that pulsatile tinnitus can be a sign of life-threatening disorders such as carotid cavernous fistulas, arteriovenous malformations, and carotid dissections. Also, posttraumatic stress disorder should be taken into consideration as a potential contributing factor. CONCLUSIONS: There is an evident mismatch between the high incidence of trauma-associated tinnitus and scarce literature on the topic. A consistent and-at best-standardized assessment of tinnitus- and hearing-related sequelae of trauma is recommended both for the improvement of clinical care and for a deeper understanding of the various pathophysiological mechanisms of trauma-associated tinnitus.

Inner ear damage following electric current and lightning injury: a literature review.

Audiovestibular sequelae of electrical injury, due to lightning or electric current, are probably much more common than indicated in literature. The aim of the study was to review the impact of electrical injury on the cochleovestibular system. Studies were identified through Medline, Embase, CINAHL and eMedicine databases. Medical Subject Headings used were 'electrical injury', 'lightning', 'deafness' and 'vertigo'. All prospective and retrospective studies, case series and case reports of patients with cochlear or vestibular damage due to lightning or electrical current injury were included. Studies limited to external and middle ear injuries were excluded. Thirty-five articles met the inclusion criteria. Fifteen reported audiovestibular damage following electric current injury (domestic or industrial); a further 15 reported lightning injuries and five concerned pathophysiology and management. There were no histological studies of electrical current injury to the human audiovestibular system. The commonest acoustic insult after lightning injury is conductive hearing loss secondary to tympanic membrane rupture and the most frequent vestibular symptom is transient vertigo. Electrical current injuries predominantly cause pure sensorineural hearing loss and may significantly increase a patient's lifetime risk of vertigo. Theories for cochleovestibular damage in electrical injury include disruption of inner ear anatomy, electrical conductance, hypoxia, vascular effects and stress response hypothesis. The pathophysiology of cochleovestibular damage following electrical injury is unresolved. The mechanism of injury following lightning strike is likely to be quite different from that following domestic or industrial electrical injury. The formulation of an audiovestibular management protocol for patients who have suffered electrical injuries and systematic reporting of all such events is recommended.

[Trauma of the temporal bone]. / Traumata des Felsenbeins.

Temporal bone fractures are mostly due to high-energy head trauma with high rates of concurrent intracranial and cervical spine injuries and belong to the wider spectrum of lateral skull base trauma. Given that the temporal bone represents the most complex bone structure in the human body, containing a multitude of vital neurovascular structures, variable clinical presentations may arise from such fractures, ranging from asymptomatic courses to serious consequences, such as conductive and/or sensorineural hearing loss, vascular and/or cranial nerve injury as well as cerebrospinal fluid leakage. The present paper presents typical clinical sequelae and provides a detailed illustration of characteristic imaging findings related to temporal bone injury. Last but not least, in the final section of the manuscript the focus is placed on distinct anatomic structures which may mimic fracture lines and, thus, entail a high potential for misclassification as temporal bone fractures.

Posttraumatic vertigo and dizziness.

Dizziness and vertigo are common symptoms following minor head trauma. Although these symptoms resolve within a few weeks in many patients, in some the symptoms may last much longer and impede ability to return to work and full functioning. Causes of persisting or recurrent dizziness may include benign paroxysmal positional vertigo, so-called labyrinthine concussion, unilateral vestibular nerve injury or damage to the utricle or saccule, perilymphatic fistula, or less commonly traumatic endolymphatic hydrops. Some dizziness after head trauma is due to nonlabyrinthine causes that may be related to structural or microstructural central nervous system injury or to more complicated interactions between migraine, generalized anxiety, and issues related to patients self-perception, predisposing psychological states, and environmental and stress-related factors. In this article, the authors review both the inner ear causes of dizziness after concussion and also the current understanding of chronic postconcussive dizziness when no peripheral vestibular cause can be identified.

Effects of exposure to pile driving sounds on fish inner ear tissues.

Impulsive pile driving sound can cause injury to fishes, but no studies to date have examined whether such injuries include damage to sensory hair cells in the ear. Possible effects on hair cells were tested using a specially designed wave tube to expose two species, hybrid striped bass (white bass Morone chrysops × striped bass Morone saxatilis) and Mozambique tilapia (Oreochromis mossambicus), to pile driving sounds. Fish were exposed to 960 pile driving strikes at one of three treatment levels: 216, 213, or 210dB re 1 µPa(2)·s cumulative Sound Exposure Level. Both hybrid striped bass and tilapia exhibited barotraumas such as swim bladder ruptures, herniations, and hematomas to several organs. Hybrid striped bass exposed to the highest sound level had significant numbers of damaged hair cells, while no damage was found when fish were exposed at lower sound levels. Considerable hair cell damage was found in only one out of 11 tilapia specimens exposed at the highest sound level. Results suggest that impulsive sounds such as from pile driving may have a more significant effect on the swim bladders and surrounding organs than on the inner ears of fishes, at least at the sound exposure levels used in this study.

Inner ear decompression sickness in scuba divers: a review of 115 cases.

Inner ear decompression sickness (IEDCS) in scuba divers is increasingly observed, but epidemiological data are limited to small case series and the pathogenesis remains elusive. We report our experience over a 13-year period. We also thought to demonstrate that the development of this injury is mainly attributed to a mechanism of vascular origin. Diving information, clinical data, presence of circulatory right-to-left shunt (RLS), and laboratory investigations of 115 recreational divers were retrospectively analyzed. A follow-up study at 3 months was possible with the last 50 consecutive cases. IEDCS (99 males, 44 ± 11 years) represented 24 % of all the patients treated. The median delay of onset of symptoms after surfacing was 20 min. Violation of decompression procedure was recorded in 3 % while repetitive dives were observed in 33 %. The median time to hyperbaric treatment was 180 min. Pure vestibular disorders were observed in 76.5 %, cochlear deficit in 6 % and combination of symptoms in 17.5 %. Additional skin and neurological disorders were reported in 15 % of cases. In 77 %, a large RLS was detected with a preponderant right-sided lateralization of IEDCS (80 %, P < 0.001). Incomplete recovery was found in 68 % of the followed patients. Time to recompression did not seem to influence the clinical outcome. IEDCS is a common presentation of decompression sickness following an uneventful scuba dive, but the therapeutic response remains poor. The high prevalence of RLS combined with a right-sided predominance of inner ear dysfunction suggests a preferential mechanism of paradoxical arterial gas emboli through a vascular anatomical selectivity.

Susceptibility of the inner ear structure to shunt-related decompression sickness.

INTRODUCTION: Decompression sickness (DCS) is caused by formation and growth of bubbles from excess dissolved gas in body tissues following reduction in ambient pressure. Inner ear decompression sickness (IEDCS) is a complex disorder involving the vestibulo-cochlear apparatus whose pathophysiology remains incompletely understood. METHODS: The records of 662 consecutive DCS cases treated over a 7-yr period at 2 UK hyperbaric units were examined for symptoms suggesting IEDCS (nausea, vomiting, dizziness, and hearing loss arising within 2 h of surfacing). For IEDCS cases, demographics, dive, treatment, and outcome data were extracted with particular attention to the outcome of testing for a right-to-left shunt. RESULTS: Included were 31 men and 2 women with a mean age of 46 yr (range 31-61 yr). Of these, 16 patients had isolated IEDCS and 17 patients had associated symptoms ranging from joint pain to tingling and numbness. The depth of the dive leading to the incident ranged from 49-256 ft (15-78 m). As primary treatment, 21 patients received a U.S. Navy Treatment Table 6 (USN TT6) and 11 patients received a Comex 30. No difference in the speed of recovery or number of treatments needed was seen between the two tables. All patients were advised to have a right to left shunt (RLS) check, but only 30 complied with that, with 24 (80%) testing RLS positive. CONCLUSION: Our retrospective study confirms the correlation between IEDCS and the presence of a significant patent foramen ovale (PFO). In our series 48% of patients had an isolated IEDCS. IEDCS responds slowly to treatment irrespective of the initial table used. Recovery is thought to be mainly a central compensation process.

Management of blast ear injuries in mass casualty environments.

OBJECTIVES: To establish a management pathway for blast ear injuries in mass casualty environments and to review the management of ear injuries caused by blast. METHOD: Relevant literature search on blast injury was performed through MEDLINE. RESULTS: Comprehensive review of management of blast injuries of the ear was undertaken. There was an overview of the pathophysiology of blast and detailed discussion of management of injuries of the external, middle, and inner ear. With any ear symptoms or injury, the patient should be referred to the otolaryngologist for further management. CONCLUSION: The management of blast injury should ensure detection at an early stage, potentially life-threatening cases in mass casualty situations and ensuring that subtle injuries affecting the ear are not missed.

[Update: blast and explosion trauma]. / Update: Knall- und Explosionstraumata.

In recent decades, acoustic shock and explosion traumas have increased in frequency in the general population. Beside the use of fireworks and firearms, airbag ignitions and explosions caused by terror or suicidal acts are also relevant. Depending on duration and strength of the sound pressure affecting the human ear, isolated inner ear damage or additional ear drum perforation and interruption of the middle ear ossicle chain can result. By means of otoscopy, pure tone audiometry, measurement of otoacoustic emissions, and other neurootological examinations, the severity of the trauma can be determined. With prompt and adequate therapy, permanent hearing loss can be minimized. In particular, the measurement of otoacoustic emissions allows conclusions to be made on the functionality of the outer hair cells which are damaged first in most cases. Histological investigations on noise-exposed cochleas show extensive damage to the outer hair cells in the frequency range between 1.0 and 4.0 kHz, which correlates well with audiometric measurements.

[Imaging of the temporal bone]. / Bildgebung des Schläfenbeins.

This article presents a review of diseases of the temporal bone which are relevant for radiologists in routine clinical practice. First the most prominent imaging methods will be briefly summarized with respect to the current state of the art and the most important aspects of cross-sectional anatomy of the temporal bone will be presented. This is followed by the presentation of various inflammatory diseases. Fractures (longitudinal, transverse and mixed fractures), auditory ossicle lesions and contusions of the labyrinth will be discussed in connection with injuries of the temporal bone. Tumors and tumor-like lesions and the clinical symptoms of otosclerosis and malformations will also be discussed. Finally the postoperative use of imaging methods will be presented. Special importance is given to the position of imaging techniques in the diagnostic chain and their evidential value. This is supplemented by special morphological imaging characteristics and aspects of differential diagnostics.

Spontaneous hydrocele resolution after hyperbaric oxygen treatment: a clinical case report.

Hyperbaric oxygen is considered an adjunctive treatment to medical and surgical care. We present a unique case in which a male patient with decompression illness affecting inner ear and spinal cord presented a worsened unilateral hydrocele synchronously with the neurological pathology. At the Diving and Hyperbaric Medicine Department, the patient was initially recompressed using a modified United States Navy Treatment Table 6A; on the following days he was treated for decompression illness using hyperbaric oxygen. Hyperbaric oxygen treatment has not been used for the treatment of hydrocele, but disappearance of the hydrocele occurred during the time he was treated with hyperbaric oxygen for decompression illness. He was discharged on Day 8, free of symptoms, having a normal neurological examination.