A perilymph fistula is a tear or defect in the oval window and/or the round window, the small, thin membranes that separate the middle ear from the fluid-filled inner ear. When a fistula is present, changes in middle ear pressure will directly affect the inner ear, stimulating the balance and/or hearing structures and causing symptoms.
The symptoms of perilymph fistula may include dizziness, vertigo, imbalance, nausea, and vomiting. Some people experience ringing or fullness in the ears, and many notice a hearing loss. Most people with fistulas find that their symptoms get worse with changes in altitude (elevators, airplanes, travel over mountain passes) or air pressure (weather changes), as well as with exertion and activity.
Head trauma is the most common cause of fistulas. Fistulas may also develop after rapid or profound changes in intracranial or atmospheric pressure, such as may occur with SCUBA diving, aerobatic maneuvers in airplanes, weightlifting, or childbirth. Fistulas may be present from birth or may result from chronic, severe ear infections. Rarely, they appear to occur spontaneously.
History, physical examination, and vestibular and audiometric test results are used to assist in establishing the diagnosis of perilymph fistula. However, the only positive way the diagnosis can be confirmed is by performing a tympanotomy (operation) and directly viewing the area of the suspected fistula.
In many cases, a fistula will heal itself with strict bed rest, to give the fistula a chance to close. If symptoms are severe and have not responded to bed rest, or if progressive hearing loss has occurred, surgical repair of the fistulas may be required.