Perilymphatic Fistula

Perilymphatic fistula (PLF) is the abnormal passage of fluid in the perilymphatic space between the bony and membranous labyrinth of the inner ear into the middle ear or mastoid. This transition usually occurs through the oval or round window and can lead to a variety of clinical presentations with cochlear and/or labyrinthine dysfunction. Congenital anomalies of the temporal bone, post-stapes surgery, trauma and barotrauma, and sometimes a sudden increase in intracranial pressure after a vigorous Valsalva maneuver can lead to the formation of a PLF. The primary symptoms of PLF are progressive, sudden, or fluctuating sensorineural hearing loss, dizziness, and/or vertigo. The diagnosis can be made on the basis of the patient’s symptoms and findings together with a medical history and biochemical, audiovestibular, and radiological examinations. Cochlin tomoprotein is a protein defined in 2001 and found only in perilymph. Since its introduction in the literature by Ikezono et al. in 2009, it has been used as a biomarker for the diagnosis of PLF. The treatment of PLF is as controversial as its diagnosis. There are two main approaches: the conservative approach and immediate surgical intervention. The choice of treatment is based on the etiology of PLF and the severity of symptoms.