Initial Severity Scoring and Residual Deficit in Scuba Divers with Inner Ear Decompression Sickness.

BACKGROUND: Inner ear decompression sickness (IEDCS) in scuba diving results in residual vestibulocochlear deficits with a potential impact on health-related quality of life. The aim of this study was to determine the predictive factors for poor clinical recovery and to try to establish a prognostic score on initial physical examination. METHODS: The medical records of injured divers with IEDCS treated in our facility between 2009 and 2014 were retrospectively analyzed. The clinical severity of the deficit was evaluated on admission using a numerical scoring system taking into account the intensity of vestibular symptoms and the presence of cochlear signs. The clinical outcome was assessed at 3 mo by telephone interview. After multivariate analysis of potential risk factors for sequelae, the discriminating value of the score and these prognostic reliability indices were calculated. RESULTS: Among the 99 patients included in the study, 24% still had residual symptoms. Statistical analysis revealed that only a high clinical score [OR = 1.39 (95% CI 1.13-1.71)] and a delay in hyperbaric recompression >6 h [OR = 1.001 (95% CI 1-1.003)] were independently associated with incomplete recovery. The advantage of the score lay in its highly specific nature (92%) rather than its sensitivity (48%) for a threshold of 10. CONCLUSION: Results suggest that the severity of IEDCS can be easily determined by a clinical score during the acute phase. Recompression treatment should not be delayed. Gempp E, Louge P, de Maistre S, Morvan J-B, Vallée N, Blatteau J-E. Initial severity scoring and residual deficit in scuba divers with inner ear decompression sickness. Aerosp Med Hum Perform. 2016; 87(8):735-739.

Medical ozone therapy for the inner ear acoustic trauma.

OBJECTIVES: The goal of the study was to look at the potential protective effect of ozone therapy by studying its antioxidant and vasodilatation effects against hearing loss caused by acoustic trauma. METHODS: Thirty-two male Wistar Albino rats were divided into four groups of eight. The 1st group was exposed to acoustic trauma, the 2nd group was treated with ozone initially, and was exposed to acoustic trauma 24 h later, the 3rd group received ozone without trauma, while the 4th group was the control group. The 1st and 2nd groups were exposed to acoustic trauma with 105 dB SPL white band noise for 4h. DPOAE and ABR tests were conducted in all groups on the 1st, 5th, and 10th days after trauma. RESULTS: In the 1st group, the effects of acoustic trauma continued on days 1, 5 and 10. The 2nd group's DPOAE and ABR results on days 5 and 10 showed significant improvement at all frequencies compared to deterioration on day 1, and the readings were comparable to baseline measurements. CONCLUSION: Acoustic trauma is a pathology that is experienced frequently and leads to many problems in terms of health and cost. Ozone was demonstrated to be a reparative substance against acoustic trauma and, in addition, it can be supplied and applied easily.

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.

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.

Early hearing assessment after "one shot" CO2 laser stapedotomy: is it helpful to predict inner ear damage and the functional outcome?

OBJECTIVE: Auditory testing is not routinely performed within 4 to 6 weeks after stapedotomy because hearing acuity is thought to be transiently depressed. The early postoperative effects of the 1-shot carbon dioxide (CO2) laser have never been reported. The purpose of this study is to present data for auditory thresholds measured within 2 days of laser stapedotomy and at the last follow-up. STUDY DESIGN: The study was prospective and unblinded. SETTING: The study was conducted at the "A. Gemelli" University Hospital. METHODS: From January to December 2008, 58 subjects underwent "1-shot" CO2 laser stapedotomies for otosclerosis. Pure-tonal audiometric test was performed preoperatively 2 days after surgery and at least 1 month after surgery during the follow-up. RESULTS: The closure of air-bone gap began in the early postoperative period and continued to improve through the late postoperative period. Bone-conduction hearing thresholds were stable even in the early postoperative follow-up and remained stable trough all the course of the study. CONCLUSION: Our data, supported by the literature, suggest that 1-shot CO2 laser stapedotomy is an effective and safe procedure for the treatment of otosclerosis.

Ear trauma caused by a yucca plant leaf spine.

Three uncommon cases of ear trauma caused by a yucca plant leaf spine are presented. One patient presented with tympanic perforation and the second with mixed hearing loss after spontaneous closure. The third patient probably had a perilymphatic fistula with subsequent labyrinthitis and hearing loss. Although the yucca is a ubiquitous plant, to the best of our knowledge, such incidents have not been previously reported.

Barotrauma and decompression illness of the inner ear: 46 cases during treatment and follow-up.

INTRODUCTION: Diving accidents affecting the inner ear are much more common than was once thought. Among the 319 patients treated in our clinic between January 2002 and November 2005, 46 cases involved 44 divers with symptoms of acute inner ear disorders. The objective of the present article is to investigate the symptoms of the acute disorders and assess any residual damage. STUDY DESIGN: Retrospective case analysis. MATERIALS AND METHODS: The medical records were used to study the cases of 18 divers treated for inner ear decompression illness on 20 occasions and 26 divers who had inner ear barotrauma. The symptoms of the disorder at the beginning of treatment, latency period before the first therapeutic measures, kind of initial therapy, symptoms after the accident, and hearing and balance functions at the last examination in our clinic were assessed. Divers with inner ear decompression illness were examined via means of transcranial or carotid Doppler ultrasonography for the presence of a vascular right-to-left (R/L) shunt. RESULTS: Of 18 divers with inner ear decompression illness, 17 reported vertigo as the main symptom. In one diver, the inner ear decompression illness was manifested bilaterally. The divers with inner ear decompression illness had been treated with hyperbaric oxygen therapy in 14 of 20 cases; the average latency period before the start of therapy was 40 hours (median, 10 h). In 15 (83%) of 18 patients, a large R/L shunt was detected, and in 14 (78%) of 18 patients, residual cochleovestibular damage was detected. Only 9 of 26 patients with inner ear barotrauma mentioned feeling dizzy, and in no patient was vertigo the main symptom. Twenty-one patients complained of tinnitus, whereas 20 complained of hearing loss. The hearing loss ranged from an unobtrusive difference of 10 dB between the ears up to complete deafness. Three patients were subjected to tympanoscopy because of suspected rupture of the round window membrane. Of patients with inner ear barotrauma, 78% had residual cochleovestibular damage. CONCLUSION: We describe for the first time a patient with bilateral manifestation of inner ear decompression illness. Inner ear decompression illness is frequently associated with a R/L shunt; therefore, after a diving accident, the patient's fitness to dive should be assessed via a specialist in diving medicine. Both decompression illness and barotrauma of the inner ear result in residual cochleovestibular damage in more than three of four patients.

[Treatment of acute cochleovestibular damage after diving]. / Behandlung akuter kochleovesibulärer Schädigungen nach dem Tauchen.

BACKGROUND: There has been a steady in-crease of recreational scuba divers in the last years. The majority of diving associated diseases involve otorhinolaryngology, the most important of which are cochleovestibular dysfunctions as these can lead to permanent inner ear failure. MATERIAL AND METHODS: We discuss the origin and clinical symptoms, as well as the therapy, of both inner ear barotrauma and inner ear decompression illness. Our own experiences are considered together with a review of the literature from the last decade. RESULTS: Inner ear decompression illness seems to be a relatively common diving associated incident and is not as rare as previously thought. DISCUSSION: Hyperbaric oxygen therapy is the treatment of choice for patients with inner ear decompression sickness, but is contraindicated in patients with inner ear barotrauma. As long as an inner ear decompression illness can not be ruled out, we suggest that every patient should be treated using hyperbaric oxygen therapy but only after bilateral paracentesis.

Recurrent inner ear decompression sickness associated with a patent foramen ovale.

Isolated inner ear injuries occurring during shallow scuba dives are an uncommon manifestation of decompression sickness in recreational divers. We describe a patient who presented with the typical symptoms of inner ear involvement after 2 independent dives within the decompression limits. The diver reported symptoms of unilateral (right-sided) hearing loss, tinnitus, and vertigo after dives to 35 and 50 m. After treatment with hyperbaric oxygen, his symptoms completely resolved. To confirm the hypothesis of inner ear decompression sickness (IEDCS), we examined the patient for a right-to-left shunt by cranial Doppler ultrasound and found a patent foramen ovale. The existence of a patent foramen ovale is suspected to be a risk factor for developing neurological symptoms of decompression sickness. There was no evidence of any other risk factors, so we suggest that the relevant right-to-left shunt in our patient may have been the predisposing factor that caused the inner ear symptoms during his scuba dive.

Preventive magnesium supplement protects the inner ear against noise-induced impairment of blood flow and oxygenation in the guinea pig.

We have recently demonstrated in the guinea pig that preventive dietary magnesium supplement can significantly reduce hearing loss caused by acute impulse noise exposure. To elucidate the underlying protective mechanisms of magnesium, the present study examined its effect on noise-induced impairment of cochlear blood flow (CoBF) and perilymphatic oxygen partial pressure (pO2) in two groups of guinea pigs maintained on optimal or suboptimal dietary magnesium status. While laser Doppler flowmetry was used to determine CoBF, perilymphatic pO2 was measured polarographically using micro-coaxial platinum needle electrodes. Auditory function was tested by recording compound action potentials. Animals were exposed to a selected high-intensity impulse noise series (L(peak) 167 dB, 1/s, 38 min). In the low magnesium groups, the noise exposure resulted in a mean decrease of CoBF and perilymphatic PO2 by about 10 and 35 per cent of the initial value, respectively. In contrast, in the high magnesium groups, neither parameter displayed any noise-induced decreases, and there was even a tendency to a slight increase. Magnesium also reduced the hearing loss significantly by 10 to 35 dB over the frequency range (2-16 kHz) tested. Both the CoBF and the perilymphatic pO2 were found to correlate with the serum magnesium. The piesent findings show that in the guinea pig preventive dietary magnesium supplement can protect the inner ear against noise-induced impairment of blood flow and oxygenation, which may partly be responsible for noise-induced hearing loss.

Inner ear decompression sickness following altitude chamber operation.

Decompression sickness (DCS) is a known hazard of altitude chamber operation. The musculoskeletal, dermal, neurological and pulmonary manifestations of DCS are well recognized, but inner ear injury has not been reported. We present the unusual case of a medical corpsman suffering from vestibular DCS after an altitude chamber exposure to 25,000 ft. The patient had a good clinical response to hyperbaric treatment, but there was laboratory evidence of mild residual vestibular damage with full compensation. This case suggests that aviation medical personnel should be more aware of the possible occurrence of inner ear DCS among subjects exposed to altitude.

Inner ear barotrauma after stapedectomy in the guinea pig.

OBJECTIVE: The safety of scuba diving after stapedectomy is controversial. Stapedectomy is thought to predispose to inner ear barotrauma (e.g., perilymph fistula); however, many individuals continue to scuba dive following stapedectomy without ill effects. The purpose of this study was to evaluate the cochlear effects of barotrauma, similar to that experienced with scuba diving, on inner ears previously treated with stapedectomy. STUDY DESIGN: Prospective, controlled. METHODS: Sixteen Hartley albino guinea pigs underwent unilateral total stapedectomy followed by hyperbaric dives on 5 consecutive days, beginning 3 weeks after stapedectomy. Cochlear effects were determined using click and tone-pip evoked electrocochleographic thresholds and cochlear hair cell counts. RESULTS: Mean auditory thresholds increased by 29 dB after stapedectomy (P < .001), then remained stable thereafter. Mean thresholds in both the operated and control ears did not change with hyperbaric dives. Evidence of middle ear barotrauma (e.g., hemorrhage or tympanic membrane perforation) was observed in eight poststapedectomy ears and five control ears, but none demonstrated significant threshold elevation greater than or equal to 10 dB. Hair cell counts were not different between operated and control ears. CONCLUSIONS: Stapedectomy does not appear to predispose to cochlear sequelae in the guinea pig model of diving-related barotrauma.

An electrophysiologic study of the guinea pig inner ear following low pressure barotrauma.

We examined electrophysiologic and morphologic changes following low pressure barotrauma in 25 guinea pigs. Compound action potentials (CAPs), cochlear microphonics (CMs), and transiently evoked otoacoustic emissions (TEOAEs) were elicited by tone bursts (1, 2, 4 and 8 kHz) or non-linear clicks immediately following barotrauma. CAP threshold elevations were observed in 19 out of 25 cochleas, mainly at lower stimulus frequencies. Furthermore, CM and TEOAE thresholds were significantly increased, while CAP and CM amplitudes demonstrated reductions at all stimulus frequencies and intensities. CAP N1 latencies exhibited slight elongations at all stimulus frequencies and intensities. The regression coefficient between the mean CAP thresholds of four stimulus frequencies and TEOAE thresholds was statistically significant. Scanning electron microscopy (SEM) study of six electrophysiologically abnormal cochleas revealed stereocilia morphology in four, but no changes in two. We hypothesize that low pressure barotrauma can injure inner ear hair cells through an early threshold shift secondary to dislocation of the basement membrane.

Inner and middle ear hyperbaric oxygen-induced barotrauma.

Patients receiving hyperbaric oxygen (HBO) therapy can sustain inner and middle ear barotrauma. The purpose of this study is to define the incidence and significance of HBO-related barotrauma, in addition to establishing guidelines for prophylactic myringotomy or tympanostomy tube placement. Thirty patients were stratified into two groups (those able to autoinflate and those unable to autoinflate the middle ear) and barotrauma was assessed by otoscopy, tympanometry, high-frequency audiometry, and distortion product otoacoustic emission (DPOAE) testing. Ten of 11 patients (91%) from the noninflater group suffered middle ear barotrauma, and seven of 19 patients (37%) from the autoinflater group sustained middle ear barotrauma. Patients unable to autoinflate the middle ear were shown to have a higher incidence and greater severity of barotrauma than patients able to autoinflate. Pretreatment pressure-equalizing tubes or myringotomies should be considered for patients undergoing HBO therapy who have an artificial airway or have eustachian tube dysfunction and have failed conservative medical intervention. A significant change in DPOAEs (loss of emissions over a 1-kHz range) was found in four of 15 autoinflaters (27%) and two of seven noninflaters (29%). There was no significant difference between the groups. The decrease in DPOAEs was not associated with a change in conventional audiometry.

Exploration of cochlear function by otoacoustic emissions: relationship to pure-tone audiometry.

The amplitudes, growth functions and detection thresholds of evoked otoacoustic emissions (EOE) were measured in 44 normally hearing subjects and 138 patients with two categories of cochlear dysfunctions: (a) acoustic trauma; and (b) presbycusis. Separate sets of experiments were also performed: (a) detection of stimulus frequency emissions; and (b) click EOE. EOE properties were studied around 2 kHz, 1 kHz and 0.75 kHz (+/- 0.1 kHz). A partial correlation and multivariate analysis was carried out to investigate the relationships between EOE properties and puretone auditory thresholds (from 0.25 to 8 kHz, half-octave steps). For each experiment and each frequency, only one highly significant correlation was found, linearly relating the n kHz EOE threshold with the hearing threshold at 2n kHz: there was a shift of about one octave between EOE amplitudes and audiometric data. This means that EOE thresholds give no direct information about the local cochlear state. A simplified model has been implemented, which assumes that EOE thresholds and amplitudes are proportional to the total number of residual active sites along the organ of Corti, i.e., to the total length of active basilar membrane towards the base of the cochlea. It is shown that this model accounts for the results revealed by the statistical analysis and closely fits the experimental data.

Auditory and vestibular disorders due to barotrauma.

In order to investigate auditory and vestibular disorders caused by barotrauma, 12 guinea pigs were exposed to compression and decompression between 1 absolute pressure (ATA) and 2 ATA in a pressure chamber. During the atmospheric pressure change, spontaneous nystagmus occurred in two thirds of the animals. Auditory dysfunction that showed the difference between the right and left ears was confirmed by auditory brain stem response and Preyer's reflex in the animals with spontaneous nystagmus. Damage to the organ of Corti was the most significant cause for the auditory dysfunction. Though findings attributed to the rupture of the round window membrane were recognized in four ears, the rupture or hemorrhage of the round window membrane was not the direct cause of the auditory dysfunction. The significance of the round window membrane rupture is discussed.

Damage of the basilar membrane by acoustic stimulation.

Sound exposures of more than 130 dB lead to typical tears in the basilar membrane in the area of maximal damage. The position, size, and number of these tears are evaluated.

Experimental aural barotrauma. Electrophysiological and morphological findings.

The electrophysiological findings show a time and pressure related decrease in function of the CM and the N1 potentials. Sudden changes were correlated with tympanic membrane perforations. Some of the decreased function is accounted for by middle ear effusion and hemorrhages, reducing mechanically the transmission of sound energy through the middle ear. This was evidenced by an improvement of function when the fluids were removed. Remaining decreases in function were interpreted as a result of influences on the inner ear function or of undisclosed middle ear changes. No differences were noted in cochlear function between animals subjected to sustained or intermittent middle ear pressures. Neither were any morphological differences noted between these two groups in the middle or inner ear. The morphological middle ear findings correlated well with previous clinically and experimentally induced changes with increased/decreased middle ear pressure. The cochlear findings include the interesting observation of an intact round window membrane, a clear endolymph, and a normal Organ of Corti in all cases. Positive findings were a high frequency of hemorrhage, most commonly demonstrated in the scala tympani of the basal turn close to the round window. The origin of the hemorrhages could not be demonstrated with the present investigation. The hemorrhages often appeared to be related to the cochlear aqueduct. The occurrence of hemorrhage was clearly related to increased negative pressure, and the non-existence of hemorrhage was always related to either tympanic membrane perforations or low applied pressure. Further frequent findings were distention, collapse, and rupture of the inner ear membranes which must be interpreted with great circumspection due to the method used. Likewise, some of the pathological cochlear findings may be due to pathological conditions which are not necessarily related to induced middle ear pressure.