Experimental Studies And Clinical Observation Of Alternobaric Vertigo In Pilots

Alterobaric vertigo(AV) is a kind of acute paroxysmal vertigo, occurred in the conditions of rapid change of atmospheric pressure and a relative overpressure in the middle ear. It is a serious and common hazard in population exposed to rapid change of atmospheric pressure such as pilots and divers. The aim of the present study was to investigate the effects of asymmetric middle ear pressure and overpressure in the middle ear on vestibular function and morphology in guinea pigs of vestibular organs. The clinical cases in pilots were also analysed, so as to sum up it's characteristics, mechanism and preventive measures.Part one: Experimental study of alternobaric vertigo for guinea pigs A group was artificially perforated right tympanic membrane, for B group left Eustachian tube were obstructed, for C group, right tympanic membrane was perforated and left Eustachian tube was obstructed, D group served as control group. Guinea pigs of experimental group and control group underwent experiments in barochamber. Spontaneous nystagmus and nystagmus of twenty guinea pigs induced by sinusoidal pendular test and rotational velocity step test were described by VTS-â…¢ vestibular function examination system before molding and after test of low pressure chamber. Morphological examination of vestibular organs was performed. The normal value of symmetrical ratio calculated from the results of sinusoidal pendular test before molding was <11.88%, rotational velocity step test was <11.56%. In the experimental groups, they all produced obvious left spontaneous nystagmus in the test of the low pressure chamber, especially the guinea pigs of C group. There were the most part of the experimental guinea pigs with SR>11.88% or SR>11.56% in the sinusoidal pendular test or rotational...