[When to suspect a perilymphatic fistula?].

INTRODUCTION: The diagnosis of perilymphatic fistula (PLF) is difficult since no single clinical situation gives the diagnosis for sure. The goal of this study is to clarify the clinical situations where you must suspect a PLF.

METHODS: Retrospective study of 20 patients that had an exploratory tympanotomy with a PLF confirmed peroperatively. An analysis of the symptoms, signs and complementary exams was done. The surgical findings and the postoperative evolution were noted.

RESULTS: 100% of patients reported a hearing loss, 80% vertigo, 70% a tinnitus and 35% equilibrium problems. Every patient had an etiological event to explain the PLF (trauma 85%), stapedotomy (10%), other ear surgeries. Five patients had a positive fistula or Vasalva test. All patients except one had an hearing loss on the audiogram (sensorineural, mixte or conductive). 50% had a CT scan, 70% of which were abnormal. A VNG was done on 3 patients. The sites of the PLF were as follows: 90% oval window, 5% round window and 5% both windows. The hearing got better or was stabilised in 95% of patients after the operation. 64% saw an improvement of their tinnitus and 87% of their vertigo.

CONCLUSION: The diagnosis of PLF is difficult and a high index of suspicion is mandatory. One must look for an etiologic situation to explain the PLF. The audiogram is almost always modified, a mixte hearing loss being common due to the high incidence of ossicular trauma associated with PLF. The clinical clinical situations where you must suspect a PLF were identified as follows: An old trauma, a recent trauma, a history of otologic surgery particularly on the stapes and a preexisting hearing loss that aggravates. A diagnosis scale to evaluate the risk of PLF, based on clinical situations, physical exam and complementary exams was done to help the clinician in the evaluation of PLF.