[Vestibular findings in divers]

The author investigated 21 professional divers who had worked in overpressure conditions for many years. Main abnormalities were found in the vestibular system, especially in the caloric and optokinetic tests; the changes appeared in 61.9% of the sample. Asymmetry and dysrhythmia of evoked nystagmic responses were ascertained in these cases. The results of the auditory and tympanometry tests were normal in most examined persons. The acoustic reflex threshold increased in 38.1%. The lower ventilatory function of the eustachian tube was found only in one case but the audiometrical test was normal. From the ethiopathogenetic point of view the frequent and intense changes of pressure, temperature and posture may cause vegetative dysregulation with the following vascular deviations in the peripheral and central vestibular apparatus and in the brain stem. The adaptive mechanisms also modify the nystagmic reactions: thus they participate in the vestibular abnormalities.