Labyrinthine fistula detection: The predictive value of vestibular symptoms and computerized tomography

A retrospective case record study of 20 patients in Oslo operated on for ch ronic otitis media with labyrinthine fistula between 1986 and 1999 was perf ormed in order to estimate the incidence of, and identify predictors for, l abyrinthine fistulas. The incidence of fistula was 0.3 per 100 000, with a median age at diagnosis of 37 years. The median duration of chronic otitis media prior to labyrinthine fistula detection was significantly correlated with age at surgery, Subjective hearing loss (90%), otorrhoea (65%) and diz ziness (50%) were presenting symptoms. Modified canal-wall-down mastoidecto my was performed in all patients. Preoperative hearing levels could not pre dict postoperative hearing outcome, Positive signs of fistula were found in only 4 patients (20%). Correspondingly, computerized tomography (CT) diagn osed the fistula in 11 patients (55%). The seven patients presenting withou t dizziness and with a negative CT scan and fistula test were characterized by lower age, absence of previous middle ear surgery, lower preoperative p ure-tone thresholds for bone conduction and better hearing outcome after su rgery. In conclusion, the identification of a younger group of patients pre senting with fewer symptoms indicates that fistulas should be suspected in all patients undergoing surgery for chronic middle ear and mastoid disease.