Abstract
To clarify the inner ear disturbance in cases of chronic otitis media (COM) with labyrinthine fistula, the pure-tone thresholds, positional nystagmus under Frenzel glasses and ENG were investigated. All 18 patients had a fistula of the lateral semicir-cular canal. Sixteen had cholesteatoma and two had no cholesteatoma but had had middle ear surgery. Advanced sensorineural hearing impairment and a high incidence of spontaneous nystagmus were found in these patients when compared with COM patients without labyrinthine fistula, whereas the quantitative analysis of ENG recordings in cases of labyrinthine fistula showed results almost equal to those with-out fistula. Thus it can be said that the inner ear disturbance in patients with labyrinthine fistula progressed gradually to the same degree as in those without fistula.
During the surgery for cholesteatoma, the cholesteatoma-matrix was removed from the semicircular canal fistula. After the fistula had been patched with free autografts of bone and fascia, tympanoplasty was performed in all cases. The average pure-tone threshold was significantly improved from 79.3dB to 68.5dB.
