音響外傷-(難聴とめまい)-について

抄録

In 51 patients with acoustic trauma, hearing test and equilibrium test were conducted. In the audiogram, gradual form of high tone loss was seen most frequently, followed by abrupt form of high tone loss, dip form and flat form. In Békésy audiometry, type II of Jerger was frequently encountered. In the eqilibrium test, central and peripheral dizziness as well as dizziness of unknown origin was noted. In animal experiment, guinea pigs were exposed to 100dB (SPL) at 4, 000Hz 12 hours a day for consecutive 40 days. The degenerative change was found in the full turn particularly around the first half of the second turn of the organ of Gorti in the cochlea. As the vestibular injury, atrophic changes were noted in the sensory epithelium of the saccular membrane, urticular membrane and semicircular canals. Mild thickening of the cerebral artery is noted. In clinical cases, angiography revealed stenosis of vertebral and vertebrobasilar arteries.
These were due to hypertension and abnormal lipid metabolism secondary to autonomic nerve imbalance and pituitary-adrenal hyperfunction.