[The "window-fistula symptom" in lesions of the round and oval window]

22 tympanoscopies in suspected perilymph fistulas with clinical symptoms such as sudden hearing loss, tinnitus, vertigo, fluctuating hearing etc., histories and intraoperative findings were registered. In some cases a remarkable interval between the implicated event and the clinical manifestation of the symptoms was noticed. Besides on case history and audiometric data the diagnosis was based on vestibular investigations. In 14 of 22 cases the window-fistula-symptom was positive. The window-fistula-symptom is defined as a provocation nystagmus with maximal intensity in the lateral head position lying on the affected ear and in the head hanging position with the head rotated to the affected side. After abandoning these positions the nystagmus is decreased. Mostly the nystagmus is directed to the healthy side. With regard to the preoperative and postoperative findings a generous indication for tympanoscopy in suspected fistulas of the round and oval window membrane is recommended.