The hearing and balance organs of the inner ear are surrounded by the temporal bone. Two areas, called the oval and round windows, allow sound to be transmitted between the middle and inner ear. These windows are normally covered by thin membranes. Certain activities, such as diving, riding in an airplane, or straining to lift a heavy weight, can cause pressure changes in the ear that cause an abnormal opening develop at the round or oval window. This is known as a perilymphatic fistula.
A perilymphatic fistula allows fluids from your inner ear to leak into the middle ear space. This can cause you to feel dizzy or have a persistent ringing (tinnitus) in your ears. The condition can also cause fluctuating hearing loss that may be mild to severe. Many patients also experience motion intolerance, lightheadedness, and vertigo, which is the sensation that you or your surroundings are spinning or rotating. The symptoms may become worse when you cough, sneeze, bend over, or engage in any activity that can change the pressure inside the head or ear.
Perilymphatic fistulas and other diving-related conditions involving the ears typically require treatment by an otolaryngologist specialized in the ear (otologist/neurotologist). The specialist will start by performing a complete history and physical exam. This will be followed by a series of tests to assess your hearing, including an audiogram, tympanogram, and a fistula test. A CT scan of the temporal bone surrounding the ear is typically used to rule out the existence of another condition that can cause the same symptoms including a posterior or superior canal dehiscence.
Non-surgical measures, such as bed rest, may provide temporary relief from your symptoms; however, this poses a risk of further damage to your hearing and balance function. A relatively new procedure for treating perilymphatic fistulas involves creating a blood patch to seal the opening. The procedure can be performed in the office and was pioneered by Dr. Djalilian at UC Irvine. It involves injecting blood into the middle ear space behind the eardrum. This technique is most often used on patients with recent onset fistulas. Most patients experience a significant improvement in their symptoms after only one injection; however, some patients do require a repeat injection.
Patients who do not notice an improvement after two blood patch injections typically must have the fistula surgically repaired. An otologist/neurotologist lifts up the tympanic membrane, also known as the eardrum, through the ear canal so that the round and oval windows can be patched. The surgery normally takes about 15-30 minutes.
Following surgery for a perilymphatic fistula, you should avoid strenuous activity for about two weeks. This means not lifting anything over 20 pounds, avoiding activities involving straining, and sleeping with your head elevated. Most patients return to their normal activities after two weeks; however, your surgeon may give you additional post-op instructions based on your situation. While most patients notice a significant improvement in their dizziness, it is common to still experience residual hearing loss.