We have recently encountered five patients with a perilymphatic fistula (PLF) judging from typical episodes at the onset. At the first visit, vestibular symptom and positional nystagmus were observed in two cases. Progressive sensorineural hearing loss was observed in all five patients, in whom expiratory tympanotomy was performed. In only two patients could the fistula be identified with perilymphatic leakage during surgery. We covered both the oval and round windows with temporal fascia and fixed them with fibrin glue in all patients. Hearing was improved by more than 30 dB in four patients (80%) and by more than 20 dB in one patient (20%) according to the criteria of sudden deafness. All the five patients showed good control of vertigo and dizziness after surgery. We should be willing to perform exploratory tympanotomy for patients suspected as having a perilymphatic fistula at the early stage around the onset to improve hearing.
