A Perilymph Fistula occurs when there is a tear in the thin membrane called the oval or round window which separates the inner ear from the middle ear. The inner ear is filled with a fluid called perilymph, so when the tear occurs this fluid leaks into the middle ear space.
What Causes a Perilymph Fistula?
The most common cause of a perilymph fistula is head trauma. It can also be caused by barotrauma, a condition that usually occurs on an airplane or while scuba diving (when there are steep changes it atmospheric pressure). More rarely perilymph fistulas can happen during childbirth, or the cause may be congenital or unknown.
Symptoms of Perilymph Fistula
Diagnosing a Perilymph Fistula
Diagnosis of a perilymph fistula can be difficult because symptoms overlap with other inner ear disorders such as Meneire's disease. Sometimes perilymph fistulas can be seen on an MRI or CT scan. The American Hearing and Research Foundation has specific recommendations on diagnosing a perilymph fistula particularly when barotrauma is not involved. Since the diagnosis can be so challenging and treatment can often involve surgical intervention, they recommend receiving a second opinion as well as the following tests to increase the likelihood of an accurate diagnosis:
- fistula test
- valsalva test
- Electrocochleography (ECOG) (a test that records the activity of the inner ear)
- Temporal bone CT scan, high resolution
Treating a Perilymph Fistula
Often strict bed rest is recommended to allow your body to repair the fistula on its own. As long as symptoms are improving your doctor may continue bed rest or strict activity restriction for up to six months before considering surgical repair of a perilymph fistula.
Certain medications may be helpful in treating symptoms but will not have any effect on the fistula itself. For example medications like ondansetron and Phenergen may be used to control nausea. Antivert is a medication used to treat different types of vertigo and may be beneficial in treating symptoms. Valium is another medication that is sometimes used.
Surgical repair involves a tissue graft to repair the tear in the round window. Unfortunately this approach is not always successful in treating a perilymph fistula. According to the American Hearing Research Foundation in a study of 160 persons about 90 percent of patients had stable or improved symptoms after surgery. None of the patients reported worsening of their symptoms.
American Hearing Research Foundation. Perilymph Fistula. Accessed: June 4, 2011 from http://www.american-hearing.org/disorders/perilymph-fistula/
Vestibular Disorders Association. Perilymph Fistula. Accessed: August 1, 2009 from http://www.american-hearing.org/disorders/unilat/perilymph_fistula.html