What is a Perilymphatic Fistula?
Perilymphatic Fistula
A perilymphatic fistula (PLF) is an abnormal opening between the fluid-filled inner ear and the air-filled middle ear (1). It often happens when a thin membrane in the inner ear tears because of an injury or a sudden change in pressure.
A perilymphatic fistula can be severely disabling and can affect every part of a person’s life. It can be profoundly challenging and frustrating to live with.
A suspected PLF should be evaluated promptly by an ear, nose and throat specialist or neurotologist. Get medical care right away for sudden hearing loss or sudden severe vertigo, especially after a head injury, a pressure change or a loud noise. Call 911 for sudden dizziness with weakness, numbness, trouble speaking or double vision.
What Are the Symptoms of a Perilymphatic Fistula?
A PLF often causes sudden, severe vertigo, hearing loss and loud ringing in the ear, usually after some kind of trauma. PLF is considered rare, but it can happen after car crashes. Some people feel or hear their ear pop right before symptoms begin (2).
Dizziness and vertigo are the most common symptoms, and they may change with the position of the head or body. Hearing loss, often in the high frequencies, is common and may last even after the dizziness settles. Tinnitus, or ringing in the ear, is also common.
The damaged inner ear membranes can create an unusual sensitivity to sound called the Tullio phenomenon, where loud sounds trigger vertigo, blurry vision, balance problems or even sudden falls (3).
Longer-lasting symptoms of PLF can include a feeling of fullness in the ear, ongoing nausea, motion sickness, a feeling of tilting to one side, headaches and trouble thinking.
What Causes a Perilymphatic Fistula?
Injury to the inner ear is the main cause of PLF. Sometimes it’s caused by pressure changes, such as during flying or scuba diving, but it’s most often caused by a blow to the head near the inner ear (1).
Fistulas usually occur in the thin membranes of the inner ear called the round and oval windows. They can also occur where the bone around the inner ear has been fractured or damaged.
A related condition is superior semicircular canal dehiscence (SSCD), in which the bone over one of the balance canals becomes thin or opens. SSCD creates a similar abnormal “third window” into the inner ear and can cause many of the same symptoms (4).
A direct injury to the ear can push the stapes, one of the tiny bones of the middle ear, into the oval window. Some people may be born with a weakness that makes a fistula more likely. A PLF can also follow a punctured eardrum, exposure to extremely loud sounds, ear infections, or even blowing your nose or sneezing hard. Some researchers believe PLF may explain a meaningful number of cases of vertigo with no known cause (2).
How Does a Perilymphatic Fistula Affect Your Life?
When a PLF first develops, symptoms are usually severe and disabling. Over a few weeks, the torn membrane may heal on its own by forming scar tissue. That scar tissue may be weaker than the original membrane, which can leave it vulnerable to tearing again. Some people have repeat fistulas and need to be careful with activities that raise pressure in the head. A PLF can come back with altitude changes, heavy lifting, straining during a bowel movement, sneezing or even hard laughing.
How Is a Perilymphatic Fistula Diagnosed?
A PLF can be hard to diagnose. Its symptoms can closely resemble Ménière’s disease, a chronic inner ear condition, but the two are treated very differently, so an accurate diagnosis matters.
A PLF is sometimes suggested by Hennebert sign, where pressure applied to the ear canal triggers involuntary eye movements called nystagmus. A test called electrocochleography, which measures the inner ear’s electrical response to sound, can help tell Ménière’s disease apart from PLF.
A CT scan can sometimes suggest a PLF. Often, the only way to confirm a fistula is during surgery (4).
How Is a Perilymphatic Fistula Usually Treated?
Many cases of sudden PLF are managed by an ear specialist with bed rest and keeping the head elevated. A typical bed rest plan involves lying with the head raised above the heart for most of the day. Straining and positions with the head down are avoided, and stool softeners are often used to prevent straining. Some people are also given medication to help them rest (5). A PLF often heals on its own within days to weeks.
In severe cases, or when bed rest doesn’t work, surgery may be needed to close the fistula. Symptoms often improve dramatically after surgical repair (4).
How the NeuroRescue Program Can Help
Our care is designed to work alongside your ear, nose and throat specialist, neurotologist and other providers, never in place of them.
PLF is considered rare, but we regularly work with people living with it. Our first priority is making sure the fistula has the chance to close. We coordinate with your ear specialist and with the skull base surgeons we work with, so you can get the right care, whether that’s a bed rest plan or surgical repair.
One challenge with PLF is that the brain gradually adapts to the faulty signals from the inner ear and treats them as the new normal. PLF can be hard to diagnose, and many people struggle with vertigo and nausea for years and see many providers before getting the right diagnosis. By then, the brain has learned to partly compensate. The brain and cerebellum are remarkably good at adapting to changes in inner ear input. But once the fistula closes, those old adaptations may no longer fit, and they can create problems of their own.
Many people notice a big improvement after a fistula closes, but some continue to have dizziness, nausea, balance problems or trouble thinking. Our care is designed to address these remaining problems by helping the brain readjust to the new signals coming from the healed ear.
When someone comes to us with PLF, we also check for signs that the brain or other parts of the nervous system may be contributing to the symptoms. If we find anything that needs further medical evaluation, we’ll refer you to the right specialist.
Depending on your needs and test results, your program may include exercises to retrain how your eyes and inner ear work together during head movement (6); eye exercises to improve visual stability (7); non-invasive electrical stimulation of the vestibular system through the skin (8); visual stimulation exercises (9), including visual stimulation combined with head movements (10); and exercises in a virtual reality environment (11). Transcranial magnetic stimulation (TMS) has also been studied for chronic dizziness (12). At our clinic, TMS is provided by our psychiatric mental health nurse practitioner, who will evaluate whether it may be appropriate for you.
No two cases of PLF are alike, and the same is true for your NeuroRescue Program. The therapies we recommend are always chosen based on your testing and exam findings, and we’ll make sure any activities are safe for a healing ear.
How the NeuroRescue Program Works
Your NeuroRescue Program begins with your Discovery Day. We start with a detailed history of your condition and your life on a timeline. This helps us understand the factors that may have contributed to where you are now, and identify related conditions that may be making it harder to move forward.
We measure how your visual, vestibular and balance systems are working through computerized analysis of your eye movements, inner ear reflexes and balance under different conditions. Our testing includes videonystagmography and saccadometry to measure several types of eye movements, the video head impulse test to measure how each semicircular canal is working, and CAPS computerized posturography to assess your balance under different sensory conditions. We also use NeuroSensoryMotor Integration testing to evaluate hand-eye coordination and cognition, and Virtualis testing to assess dynamic eye tracking and your perception of vertical in a virtual reality environment.
We combine this with a thorough physical and neurological exam of your sensory, motor, autonomic and cognitive systems. We also review any relevant lab work, imaging and prior testing, and integrate it with our findings.
Together, this helps us understand which parts of your nervous system are working well, which are struggling, and how quickly they tire. We use that information to design your personal NeuroRescue Program, aimed at improving function in the systems that need support and helping them work together. Our testing also helps us decide when to push and when to let you rest.
Our goal is to help your brain make sense of the signals from your inner ear again, so you can feel steady and move through your day with more confidence.
Your Next Step
Living with a perilymphatic fistula can be frightening and isolating, especially when it takes a long time to get answers. You don’t have to keep figuring it out alone. To find out if the NeuroRescue Program is right for you, contact one of our patient care coordinators to schedule your Discovery Day.
It’s never too late to take the next step.
References
2. Herdman SJ, Clendaniel RA. Vestibular Rehabilitation. 4th ed. F.A. Davis; 2014.
