Biomedical subjects

Z Sharoni

Publications and source records attributed to Z Sharoni.

5 recordsLinked to original sources

PubMed2001

Inner ear decompression sickness in sport compressed-air diving.

OBJECTIVE: We report our experience over the past 12 years with recreational diving-related inner ear decompression sickness (IEDCS). STUDY DESIGN: Retrospective, consecutive case series. METHODS: Twenty-four divers, representing 29 cases of IEDCS, are presented with regard to evaluation, treatment, and follow-up. RESULTS: These 29 cases represent 26% of the severe decompression sickness (DCS) cases treated in that period. The patient group includes 22 divers who had a single event of IEDCS, one diver who had two events, and one with five repeated episodes. The cause of injury in 23 cases (79%) was violation of the decompression schedule. The mean time from surfacing to appearance of symptoms was 47 +/- 65 minutes. In 83%, symptoms appeared within 1 hour of ascent, in 97% within 2 hours, and in only one diver after 5.5 hours. Ten divers (34%) had pure vestibular involvement, 4 (14%) had cochlear insult alone, and 15 (52%) had combined vestibulo-cochlear injury. Except for one patient who had central as well as peripheral vestibulo-cochlear DCS, all the remaining patients had end organ involvement only, as demonstrated by physical examination and laboratory test results. Fifteen (52%) had isolated IEDCS, whereas 14 had additional symptoms of DCS. Twenty-six cases were treated by hyperbaric oxygenation with supplementary daily hyperbaric sessions. Of the 25 cases with vestibular injury and the 19 with cochlear damage, only 7 (28%) and 6 (32%), respectively, made a full recovery, whereas the others remained with residual damage. Of the 17 treated within 6 hours of symptom appearance, 9 (53%) were cured, compared with one of the 9 treated later (P <.05). CONCLUSIONS: IEDCS related to compressed-air recreational diving is more common than previously thought, and might occur even when no decompression schedule violation took place. Prompt diagnosis leading to the early commencement of hyperbaric oxygen recompression therapy is the key to complete recovery of cochlear and vestibular function.

Adult↗

PubMed2001

Vestibular findings in professional divers.

The purpose of the present study was to investigate possible inner ear changes related to professional diving, by the documentation of auditory and vestibular function in 13 asymptomatic professional divers and 12 nondiver controls. A higher average pure tone hearing threshold, although of no clinical significance, was found in the study group (8.53 +/- 4.85 versus 6.67 +/- 3.54 dB hearing level, p = .04). In the vestibular evaluation, the smooth harmonic acceleration test phase leads for 0.01, 0.02, and 0.04 Hz were significantly lower in the divers (0.01 Hz, 38.46 degrees +/- 7.15 degrees versus 45.83 degrees +/- 9.02 degrees, p = .02; 0.02 Hz, 21.08 degrees +/- 5.19 +/- versus 25.17 degrees +/- 5.78 degrees, p = .05: 0.04 Hz, 12.38 degrees +/- 3.69 degrees versus 14.25 degrees +/- 3.14 degrees, p = .05). We suggest that the lower smooth harmonic acceleration phase values found in the professional divers, reflecting longer vestibulo-ocular reflex primary time constants and enhancement of the velocity storage mechanism, are the result of a habituation process that augments the low-frequency response of the canal-ocular system.

Adult↗

PubMed1999

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.

Adult↗

PubMed1995

[Vestibular function in acoustic trauma].

Histological and functional derangement of the vestibular system has been reported in laboratory animals exposed to high levels of noise. However, reports of clinical series give contradictory results with regard to vestibular disturbances in industrial workers and military personnel suffering from noise-induced hearing loss (NIHL). This study evaluates vestibular function in 22 men with documented NIHL and in 21 matched controls, using electro-nystagmography (ENG) and the smooth harmonic acceleration (SHA) test. There was a significantly lower vestibulo-ocular reflex gain (p = 0.05), and a tendency towards decreased caloric response in the patients. There were no differences between patient and control groups in: incidence of vertigo and of spontaneous, positional and positioning nystagmus; directional preponderance and canal paresis in the ENG; or in phase and asymmetry parameters in the SHA test. These results demonstrated a symmetrical, centrally compensated decrease in vestibular end-organ response associated with symmetrical hearing loss in the patients. Statistically significant correlations were found between average hearing loss, and decrease in average vestibulo-ocular reflex gain (p = 0.01) and ENG caloric lateralization (p = 0.02). These correlations might indicate a single mechanism for both cochlear and vestibular NIHL. The results imply subclinical, well compensated malfunction of the vestibular system associated with NIHL.

Hearing Loss, Noise-Induced↗

PubMed1991

Pressure chamber tympanometry in diving candidates.

The currently recommended examination for diving fitness ascertains middle ear autoinflation ability only under surface pressure conditions. The purpose of our study was to document and quantify middle ear pressure equalization failure during simulated dives among diving candidates who had otherwise met the otologic criteria for diving fitness. Forty-two candidates for regular naval diving activity were included in the study. Tympanograms of both ears at 1 and 1.1 absolute atmospheres (ATA) were taken inside a pressure chamber with the subjects in two positions: seated and supine. At a pressure of 1 ATA, type A tympanograms were found in all 84 ears examined. At a pressure of 1.1 ATA, with subjects in the upright position, 19 (22.9%) of the ears had type C and 2 (2.4%) type B tympanograms, while with subjects recumbent during descent, 6 of the ears (7.2%) had type C and 7 (8.4%) type B. Our results suggest that successful autoinflation at surface ambient pressure does not necessarily reflect middle ear pressure equalization ability during descent in a dive.

Acoustic Impedance Tests↗