1994 Fiscal Year Final Research Report Summary
Experimental and clinical studies on ear barotrauma caused by sudden damages of atomospheric pressure
| Project/Area Number |
04454429
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Otorhinolaryngology
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| Research Institution | Nagoya University |
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Principal Investigator |
YANAGITA Noriyuki School of Medicine Nagoya Univ.Professor, 医学部, 教授 (00023804)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUDA Shigeji same Univ.Assistant, 医学部, 講師 (90252246)
UEDA Hiromi same Univ.Assistant, 医学部, 講師 (20213358)
NAKASHIMA Tsutomu same Univ.Associate, 医学部, 助教授 (30180277)
TAKAHASHI Hideyo same Univ.Professor, 医学部, 教授 (70023819)
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| Project Period (FY) |
1992 – 1994
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| Keywords | middle ear barotrauma / inner ear barotrauma / labyrinthine window rupture / hyperbaric oxygen therapy / hemorrhage of middle ear / cochlear damage / vertibular damage / exploratory tympanotomy |
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| Research Abstract |
It has been known that the damage of acoustic organ was caused by sudden change of atomospheric pressure. We experimentally induced the barotrauma in guinea pigs by rapid decompression or/and compression using a high pressure and a low pressure chambers. The main damage to middle ear space was the hemorrhage due to the sudden pressure change. The rupture of the round window membrane was observed in about 1/3 among the ears with the inner ear barotrauma. The damage was mainly noted in the organ of Corti, in contrast with the vestibular organ. We experienced 136 patients with inner ear barotrauma that was caused by diving, landing or taking off of air plane, blowing nose, blast injury and so on. Of these patients, only 27 % combined middle ear barotrauma. In early stage, complete hearing recovery was expected in most cases. Of 16 patients, in whom we practiced the exploratory tympanotomy, 5 were found the rupture of round window membrane and 1 was found the rupture of round and oval window membranes. On the other hand, we have practiced hyperbaric oxygen therapy on patients with sudden deafness. During this therapy, middle ear barotrauma was observed in some patients. However, the barotrauma apontaneously disappeared and no cases showing the inner ear barotrauma were observed.
As to the cause of inner ear barotrauma, we speculated that the change of pressure was transmitted directly to the inner ear through the labyrinthine window membranes, giving a strong impulse to the endolymph, resulting in damage to sensory hair cells.
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