An audiologic study was performed for the patients of head injury, who were admitted to dept. of neurosurgery, Chung-Nam University Hospital during April 1975-April 1976.
Sixty cases, 26 with the temporal bone fracture, 16 with the skull fracture not involving the temporal bone, and 18 with head injury withcut fracture, were sampled, who had no history of ear trouble and ncise exposure, and could cooperate in doing pure tone audiometry.
Hearing test was done at 3rd week-3rd month after head injury. The results were as followings:
1. On otologic symptoms and findings, ear bleedings was observed in 20 cases(76.9%) with the temporeal bone fracture and 12 cases(46. 1%) showed the pathology of the exter￢nal auditory canal and 8 cases (30.7%) showed the pathology of the ear drum. Facial nerve paralysis was observed in 2 cases with the temporal bone fracture and 36 cases(60 %) complained hearing loss and 25 cases(41.6%) and 29 cases(48.3%) complained of tinnitus and vertigo after head injury.
2. On the type of hearing loss, 8 cases(18.3%) had normal hearing bilaterally, and 34 cases(56.6%) of bilateral sensorineural, 9 cases(15%) of bilateral or unilateral mixed, and 3 cases (5%) of unilateral conductive hearing loss were observed.
3. There were 36 cases(60%), that had descending curve or abrupt drop on audiogram and the maximal hearing loss was observed at high frequencies, especially at 6, 000 Kz, mostly in the cases of the temporal bone fracture.
4. Twenty-three cases(38.3%), bilaterally and 14 cases(23.3%) unilaterally showed hearing loss at the speech frequencies but there was a few in the skull fracture without the temporal bone fracture. And there 29 casese (48.3%); that had hearing loss at high frequencies without hearing loss at speech frequencies.
5. In the cases of the temporal bone fracture, there was tendency that hearing loss on the fractured ear was greater than on the contralateral ear but the satistical significancy couldn´t be noted.
6. Hearing loss after head injury had the tendency that the longer the duration of unconsciousness, the greater the hearing loss.
7. Tinnitus after head injury showed its pitch at 500 Hz and 1, 000 Hz and 25^?35 dB in its intensity.
|