Otorhinolaryngology and Diving-Part 1: Otorhinolaryngological Hazards Related to Compressed Gas Scuba Diving: A Review.

IMPORTANCE: Scuba diving is becoming increasingly popular. However, scuba diving is associated with specific risks; 80% of adults and 85% of juvenile divers (aged 6-17 years) have been reputed to have an ear, nose, or throat complaint related to diving at some point during their diving career. Divers frequently seek advice from primary care physicians, diving physicians, and otorhinolaryngologists, not only in the acute setting, but also related to the long-term effects of diving. OBSERVATIONS: The principles underpinning diving-related injuries that may present to the otorhinolaryngologist rely on gas volume and gas saturation laws, and the prevention of these injuries requires both that the diver is skilled and that their anatomy allows for pressure equalization between the various anatomical compartments. The overlapping symptoms of middle ear barotrauma, inner ear barotrauma, and inner ear decompression sickness can cause a diagnostic conundrum, and a thorough history of both the diver's symptoms and the dive itself are required to elucidate the diagnosis. Correct diagnosis and appropriate treatment result in a more timely return to safe diving. CONCLUSIONS AND RELEVANCE: The aim of this review is to provide a comprehensive overview of otorhinolaryngological complications during diving. With the increasing popularity of diving and the frequency of ear, nose, or throat-related injuries, it could be expected that these injuries will become more common and this review provides a resource for otorhinolaryngologists to diagnose and treat these conditions.

Otorhinolaryngology and Diving-Part 2: Otorhinolaryngological Fitness for Compressed Gas Scuba Diving: A Review.

IMPORTANCE: Self-contained underwater breathing apparatus (scuba) diving has become increasingly popular with millions of people diving each year. Otorhinolaryngologists are often consulted either by patients or diving physicians regarding fitness to dive, and at present, the guidelines do not provide comprehensive information regarding the evaluation of this patient cohort. The aim of this review is to provide a comprehensive overview of existing otorhinolaryngological guidelines for fitness to dive recreationally. OBSERVATIONS: There is a paucity of guidelines for assessing otorhinolaryngological fitness to dive in the recreational diver. Comprehensive guidelines exist from US, European, and UK regulatory bodies regarding fitness for commercial diving; however, not all of these can be directly extrapolated to the recreational diver. There are also a variety of conditions that are not covered either by the existing fitness for recreational diving guidelines or the commercial regulatory bodies. CONCLUSIONS AND RELEVANCE: With the paucity of recreational fitness to dive guidelines we must draw on information from the commercial diving regulatory bodies. We have provided our own recommendations on the conditions that are not covered by either of the above, to provide otorhinolaryngologists with the information they require to assess fitness for recreational diving.

Lower risk of decompression sickness after recommendation of conservative decompression practices in divers with and without vascular right-to-left shunt.

INTRODUCTION: A vascular right-to-left shunt (r/l shunt) is a well-known risk factor for the development of decompression sickness (DCS). No studies to date have examined whether divers with a history of DCS with or without a r/l shunt have a reduced risk of suffering recurrent DCS when diving more conservative dive profiles (CDP). METHODS: Twenty-seven divers with a history of DCS recommended previously to dive more conservatively were included in this study and retrospectively interviewed by phone to determine the incidence of DCS recurrence. RESULTS: Twenty-seven divers performed 17,851 dives before examination in our department and 9,236 after recommendations for conservative diving. Mean follow up was 5.3 years (range 0-11 years). Thirty-eight events of DCS occurred in total, 34 before and four after recommendation of CDP. Four divers had a closure of their patent foramen ovale (PFO). A highly significant reduction of DCS risk was observed after recommendation of CDP for the whole group as well as for the sub-groups with or without a r/l shunt. A significant reduction of DCS risk in respect to r/l shunt size was also observed. DISCUSSION: This study indicates that recommendations to reduce nitrogen load after DCS appear to reduce the risk of developing subsequent DCS. This finding is independent of whether the divers have a r/l shunt or of shunt size. The risk of suffering recurrent DCS after recommendation for CDP is less than or equal to an unselected cohort of divers. CONCLUSION: Recommendation for CDP seems to significantly reduce the risk of recurrent DCS.

Inner ear decompression sickness in compressed-air diving.

INTRODUCTION: Inner ear decompression sickness (IEDCS) has become more frequently reported in recreational diving. METHODS: We examined 34 divers after IEDCS and analyzed their dive profiles, pattern of symptoms, time of symptom onset and the association with a right-to left shunt (r/l shunt). RESULTS: Four divers used mixed gas and were excluded from the analysis. Of the remaining 30 divers, 25 presented with isolated IEDCS alone, while five divers had additional skin and neurological symptoms. All divers presented with vertigo (100%), and 12 divers reported additional hearing loss (40%). All symptoms occurred within 120 minutes (median 30 minutes) of ascent. Twenty-two of 30 divers (73.3%) showed a r/l shunt. CONCLUSION: A possible explanation for the frequent association of a r/l shunt and the dominance of vestibular rather than cochlear symptoms could be attributed to the different blood supply of the inner ear structures and the different size of the labyrinthine compartments. The cochlea has a blood supply up to four times higher than the vestibular part of the inner ear, whereas the vestibular fluid space is 30% larger. The higher prevalence of symptoms referrable to the less well-perfused vestibular organ provides further evidence that persistent local inert gas supersaturation may cause growth of incoming arterial bubbles and may therefore be an important pathophysiological factor in IEDCS.

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.

Medical and surgical treatment in divers with chronic rhinosinusitis and paranasal sinus barotrauma.

Aim of the study is to evaluate the effects of medical and surgical treatment in divers with paranasal sinus barotrauma (PSB) secondary to chronic rhinosinusitis (CRS). In this retrospective, cross-sectional, descriptive study 40 adult divers with CRS were included. Treatment of divers implied a 5-day course of a systemic steroid and a 6-week course of saline nasal irrigations and topical nasal steroid with mometasone in maximal dosage. If symptoms persisted, functional endoscopic sinus surgery (FESS) was performed. Questionnaires included the Sinonasal Outcome Test-20 German Adapted Version (SNOT-20 GAV), dive-related questions (DRQ) and general questions. Questionnaires were completed retrospectively by recalling the symptoms before and after therapy. Forty of 82 divers completed the questionnaires. Mean follow-up was 42 months (range 13-95 months). There was a statistically significant improvement of the Total score (TS) and of every subscore, except the General Quality of Life score, in the SNOT-20 GAV as well as of the TS in the DRQ. Before treatment, divers who required surgery reported significantly more symptoms than divers who were treated conservatively. Post treatment there were no significant differences between the medical and surgical group. Overall, 35 divers could resume diving after therapy even though PSB still occurred but without complications. Divers with sinus problems can successfully be managed medically and if conservative treatment fails, FESS shows a statistically significant improvement of symptoms and no serious long-term hazards for diving.

Suitability of the partially implantable active middle-ear amplifier Vibrant Soundbridge® to hyperbaric exposure.

INTRODUCTION: Active middle ear amplifiers represent a modern possibility to treat sensorineural, conductive and combined hearing loss. They can be in use in divers and patients who need hyperbaric oxygen therapy. Therefore, active middle-ear amplifiers have to be tested to determine whether or not they are prone to implosion or function loss in hyperbaric conditions. MATERIAL AND METHODS: We asked three of the companies registered by the German health authorities as manufacturers of active middle ear amplifiers to test their devices in hyperbaric conditions. Med-El agreed to support the study; Envoy stated that their devices were unable to withstand a pressure of 608 kPa; Otologics had no capacity to take part in this study. Twelve Vibrant Soundbridge® (Med-El) middle-ear amplifiers were tested in a water bath in a hyperbaric chamber. Four devices were pressurised to a maximum of 284 kPa, four devices to 405 kPa and four devices to 608 kPa, each for a maximum dive time of 78 minutes. RESULTS: The functions of the 12 devices were tested by the manufacturer pre- and post-hyperbaric exposure. Visual inspections as well as laboratory function tests were normal in all 12 devices after hyperbaric exposure. DISCUSSION AND CONCLUSION: Hyperbaric exposure to more than one bar pressure difference can result in structure damage, implosion or loss of function of the mechanical device. The Vibrant Soundbridge® middle-ear amplifier tolerated a single hyperbaric exposure to pressures of up to 608 kPa for 78 minutes with no loss of performance.

Assessment of genotoxic effects and changes in gene expression in humans exposed to formaldehyde by inhalation under controlled conditions.

Forty-one volunteers (male non-smokers) were exposed to formaldehyde (FA) vapours for 4 h/day over a period of five working days under strictly controlled conditions. For each exposure day, different exposure concentrations were used in a random order ranging from 0 up to 0.7 p.p.m. At concentrations of 0.3 and 0.4 p.p.m., four peaks of 0.6 or 0.8 p.p.m. for 15 min each were applied. During exposure, subjects had to perform bicycle exercises (∼80 W) four times for 15 min. Blood samples, exfoliated nasal mucosa cells and nasal biopsies were taken before the first and after the last exposure. Nasal epithelial cells were additionally sampled 1, 2 and 3 weeks after the end of the exposure period. The alkaline comet assay, the sister chromatid exchange test and the cytokinesis-block micronucleus test were performed with blood samples. The micronucleus test was also performed with exfoliated nasal mucosa cells. The expression (mRNA level) of the glutathione (GSH)-dependent formaldehyde dehydrogenase (FDH, identical to alcohol dehydrogenase 5; ADH5; EC 1.2.1.46) was measured in blood samples by quantitative real-time reverse transcription-polymerase chain reaction with TaqMan probes. DNA microarray analyses using a full-genome human microarray were performed on blood samples and nasal biopsies of selected subgroups with the highest FA exposure at different days. Under the experimental conditions of this study, inhalation of FA did not lead to genotoxic effects in peripheral blood cells and nasal mucosa and had no effect on the expression of the FDH gene. Inhalation of FA did also not cause alterations in the expression of genes in a microarray analysis with nasal biopsies and peripheral blood cells.

First experiences with a new adjustable length titanium ossicular prosthesis (ALTO).

CONCLUSIONS: The new length-adjustable titanium prosthesis can give good results in terms of hearing results in ossiculoplasty. The possibility to readjust the length intraoperatively was seen as a good feature. OBJECTIVE: Hearing results of ossiculoplasty with a newly designed prosthesis in 14 patients were evaluated. The prosthesis is designed to allow adjustment of length in situ. METHODS: A retrospective pilot study was carried out, comparing the preoperative and postoperative audiological and clinical results with an age- and pathology-matched group. The setting was the Department of Otolaryngology at the University of Heidelberg Medical Center, a tertiary referral center. In all, 14 patients underwent tympano-ossiculoplasty in which autologous reconstruction was not an option. The ossiculoplasty was performed as a therapeutic measure with the new titanium prosthesis. We evaluated the air­bone gap closure as established from preoperative and postoperative audiograms. We also looked at the clinical aspect of the tympanic membrane. RESULTS: The average air­bone gap came to a closure within 15 dB in 43% of the cases (6 of 14 patients). No re-perforations or extrusions of the prostheses were observed.

Decompression illness reported in a survey of 429 recreational divers.

BACKGROUND: The purpose of this study was to investigate the influence of diving experience and diving techniques on the lifetime incidence of decompression illness (DCI). METHODS: Attendants of three diving medical symposia voluntarily answered a questionnaire about their age, gender, medical history, diving experience, diving habits, diving certification levels, and diving associated incidents (cross-sectional survey). RESULTS: Out of 650 divers, 429 completed the questionnaire. The study population consisted of experienced divers with an average of 670 dives. The majority of the divers were certified diving instructors (43%). There were 37 participants (8.7%) who were classified as technical divers with an average of 1193 logged dives. There was an overall lifetime incidence of DCI of 1 per 5463 dives. The complete study group showed an increased lifetime incidence of DCI with decreased diving experience (1.97-fold to 8.17-fold higher). Of the divers, 27% reported severe DCI with neurological symptoms. The lifetime incidence for severe DCI was 1 in 20,291 dives. Again, lifetime incidence for severe DCI was increased with decreased diving certification level (1.1-fold to 13.7-fold higher). Technical divers showed a DCI lifetime incidence of 1 to 8591 dives compared to the non-technical divers with a lifetime incidence of 1 to 5077 dives (not significant). CONCLUSION: In our study population, the lifetime incidence of DCI was increased in divers with less diving experience. If further studies confirm this finding, diving federations should be encouraged to intensify their efforts of educating divers and should limit diving time and depth in inexperienced divers.

Impact of gender, age, and comorbidities on quality of life in patients with chronic rhinosinusitis.

STATEMENT OF THE PROBLEM: To evaluate the impact of gender, age and comorbidities of health-related quality of life (HR-QOL) assessments in patients with chronic rhinosinusitis. METHODS: The prospective administration of the German Adapted Version of the Sino-Nasal Outcome Test 20 (SNOT-20 GAV) to patients with chronic rhinosinusitis. Two hundred and two patients with chronic rhinosinusitis filled out the questionnaire before functional endoscopic sinus surgery (FESS) and again at the 3-month follow-up. MAIN RESULTS: Gender had a significant impact on the Overall Score (OS) and on the General Quality of Life Score (GQOL) of the SNOT-20 GAV but no influence on the disease-specific scores of 'Primary Nasal Symptoms' (PNS) and 'Secondary Rhinogenous Symptoms' (SRS). Age did not influence HR-QOL. Patients with comorbidities demonstrated lower HR-QOL scores. PRINCIPAL CONCLUSION: Women had significantly poorer QOL scores than men. It seems that the influence of gender reflects general HR-QOL views rather than illness-related expectations.

Otorhinolaryngologic disorders and diving accidents: an analysis of 306 divers.

Diving is a very popular leisure activity with an increasing number of participants. As more than 80% of the diving related problems involve the head and neck region, every otorhinolaryngologist should be familiar with diving medical standards. We here present an analysis of more than 300 patients we have treated in the past four years. Between January 2002 and October 2005, 306 patients presented in our department with otorhinological disorders after diving, or after diving accidents. We collected the following data: name, sex, age, date of treatment, date of accident, diagnosis, special aspects of the diagnosis, number of dives, diving certification, whether and which surgery had been performed, history of acute diving accidents or follow up treatment, assessment of fitness to dive and special remarks. The study setting was a retrospective cohort study. The distribution of the disorders was as follows: 24 divers (8%) with external ear disorders, 140 divers (46%) with middle ear disorders, 56 divers (18%) with inner ear disorders, 53 divers (17%) with disorders of the nose and sinuses, 24 divers (8%) with decompression illness (DCI) and 9 divers (3%) who complained of various symptoms. Only 18% of the divers presented with acute disorders. The most common disorder (24%) was Eustachian tube dysfunction. Female divers were significantly more often affected. Chronic sinusitis was found to be associated with a significantly higher number of performed dives. Conservative treatment failed in 30% of the patients but sinus surgery relieved symptoms in all patients of this group. The middle ear is the main problem area for divers. Middle ear ventilation problems due to Eustachian tube dysfunction can be treated conservatively with excellent results whereas pathology of the tympanic membrane and ossicular chain often require surgery. More than four out of five patients visited our department to re-establish their fitness to dive. Although the treatment of acute diving-related disorders is an important field for the treatment of divers, the main need of divers seems to be assessment and recovery of their fitness to dive.

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.

Transsynaptic delivery of nanoparticles to the central auditory nervous system.

CONCLUSION: Silica nanoparticles may serve as a nonviral delivery system to the sensory hair cells, spiral ganglion cells within the cochlea, and the vestibular organ, as well as the cochlear nucleus. OBJECTIVES: At present there are no targeted therapeutics for inner ear disease. A variety of viral vector systems have been tested in the inner ear with variable efficacy but they are still not regarded as safe systems for inner ear delivery. Nanoparticles are a nonviral method of delivering a variety of macromolecules that potentially can be used for delivery within the auditory system. In this study, we evaluated the distribution and safety of nanoparticles in the inner ear. MATERIALS AND METHODS: Cy3-labeled silica nanoparticles were placed on the round window membrane of adult mice. Hearing thresholds were determined after nanoparticle delivery by auditory brainstem responses (ABRs). Distribution of particles was determined by histological evaluation of the cochlea, vestibular organs, and brain stem. RESULTS: Fluorescent microscopy demonstrated Cy3-labeled nanoparticles signals in the sensory hair cells and the spiral ganglion neurons of both the treated and contralateral inner ears. Additionally, the distal part of the central auditory pathway (dorsal cochlear nucleus, superior olivary complex) was found to be labeled with the Cy3-linked silica nanoparticles, indicating a retrograde axonal transport. No hearing loss or inflammation was noted in the treated cochlea.

Alternobaric vertigo--really a hazard?

OBJECTIVE: To determine the prevalence of alternobaric vertigo (AV) in sport divers and to find out whether AV led to dangerous situations underwater. Furthermore, to examine whether objective neurootologic tests are associated with the manifestation of AV. DESIGN: Retrospective cohort study. PARTICIPANTS: Sixty-three sport divers with an average diving experience of 10 years and 650 dives were questioned regarding their medical and diving history and the manifestation of vertigo during diving. METHODS: Microscopic otoscopy, tympanometry, stapedius reflexes, hearing threshold for air and bone conduction, caloric video-oculography including analysis of the slow-phase velocity of the nystagmus, acoustic brain stem responses, and magnetic resonance imaging were performed to find possible differences between divers with and without AV. RESULTS: We found 17 divers with AV (27%). There was no significant difference in all measured parameters apart from sex and history of middle ear equalization difficulty in divers with AV. Ten (59%) of 17 female divers and 7 (15%) of 46 male divers experienced AV, representing a significant sex difference (p < 0.001). Correlation with our divers' outpatient clinic revealed that female divers had a significantly higher incidence of middle ear equalization disorders which could be an explanation for the predominance of female divers with symptoms of AV. None of the divers reported any dangerous or life-threatening situations following AV. Whether AV leads to dangerous situations underwater remains unclear, but this hypothesis is not supported by our data. CONCLUSION: Alternobaric vertigo is a common finding in divers. In our study group, female divers had a four-time higher risk to suffer AV. Our data do not support the thesis that AV is a life-threatening condition.

Temporomandibular disorders in association with scuba diving.

OBJECTIVE: To determine the prevalence of temporomandibular disorders (TMD) in scuba divers and to identify the risk factors for the development of pain in the stomatognathic system before and after diving by the use of a questionnaire. DESIGN: : Retrospective cohort study based on questionnaires. PARTICIPANTS: A total of 296 active divers, aged 18 to 65 years, participating in scuba diving meetings in Heidelberg, Germany. INTERVENTIONS: Each diver answered a questionnaire containing 29 questions, predominantly on symptoms of TMD. MAIN OUTCOME MEASURES: The data collected from the divers were calculated by the use of logistic regression tests. Risk factors for the development of TMD were evaluated. RESULTS: Clenching seemed to be the greatest risk factor for pain while holding the mouthpiece and for pain in the masticatory muscle system after diving. Limited mouth opening and clenching were responsible for the development of pain in the temporomandibular joint after the dive. The prevalence of TMD-related symptoms was higher in women before, during, and after the dive. CONCLUSIONS: Individuals exhibiting TMD-related symptoms seem to be at the greatest risk of developing pain in the masticatory muscle system and/or the temporomandibular joint during or after the dive.

Hearing threshold in sport divers: is diving really a hazard for inner ear function?

OBJECTIVE: To investigate the effect of scuba diving on the hearing threshold of sport divers who have no history of excessive noise exposure or of diving-related inner ear damage. DESIGN: Cross-sectional controlled comparison study. SETTING: General sports diving community. PARTICIPANTS: Sixty sport divers with an average of 650 dives each and at least 4 years of diving experience (mean, 10 years) were compared with a control group of 63 nondivers from our hospital staff or patients referred for rhinologic problems or benign tumors of the salivary gland. MAIN OUTCOME MEASURE: After microscopic otoscopy and tympanometry, we used pure-tone audiometry to measure the hearing threshold for air and bone conduction. The participants were divided into 3 age groups, and the hearing test results for both ears combined were statistically compared. RESULTS: There were no statistically significant differences in the hearing thresholds between sport divers and nondivers. CONCLUSIONS: The reduced hearing levels of professional divers found in other studies are probably due to the high noise levels that they have to deal with or may be a result of inner ear accidents.

Embolic inner ear decompression illness: correlation with a right-to-left shunt.

OBJECTIVES/HYPOTHESIS: Inner ear decompression illness is thought to be a rare phenomenon in recreational divers, isolated signs and symptoms of inner ear dysfunction usually being attributed to inner ear barotrauma. STUDY DESIGN: We present 11 cases of inner ear dysfunction in nine divers with inner ear decompression illness. RESULTS: All nine divers had significant right-to-left shunt as diagnosed by transcranial Doppler sonography. CONCLUSIONS: The authors thought that mechanism of causation in these cases may have been intravascular bubble emboli and that inner ear decompression illness may be more common among recreational divers than currently recognized. Failure to treat inner ear decompression illness with recompression therapy can result in permanent disability. Because the differential diagnosis between inner ear barotrauma and inner ear decompression illness can be impossible, the authors suggested that divers who present with inner ear symptoms following a dive should have recompression immediately after having undergone 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.