[Audiological and equilibrium study of perilymphatic fistulas]

We clinically analyzed 15 cases of perilymphatic fistulas--11 caused by barotraumas and 4 idiopathic--identified by surgery between March 1995 and March 1999 at the Hyogo College of Medicine and affiliated hospitals. Subjects were 11 men and 4 women (aged 14 to 79 years (mean: 46.7 years)). All showed hearing loss in audiography and 12 cases reported tinnitus--stream-like in 5 and poping in 4. Dysequilibrium was seen in 9 cases. Perilymph leakage was detected intraoperatively from the oval window in 9, from the round window in 4, and from both windows in 1, while another had leakage from the fissura ante fenestram. After surgery, hearing level improved by over 10 dB in 9 of the 11 cases operated on within 14 days after onset. Hearing did not improve in 3 of 4 operated on later. Vertigo disappeared after surgery. Dizziness tended to persist in those having canal paresis or paralytic nystagmus before surgery. We suggest that patients with progressive hearing loss should be operated on as soon as possible and that patients with dysequilibrium or without response to conservative treatment undergo surgery within 14 days of onset.