What is a Perilymphatic Fistula?

Jul 27

A perilymphatic fistula (PLF) is an abnormal communication between the fluid-filled area of the inner ear and the air-filled space of the middle ear (1). They often result from ruptured membranes in the inner ear as a consequence of trauma or pressure changes.

A perilymphatic fistula can be a severely disabling condition, and can negatively impact all aspects of a person’s life. They can be profoundly challenging and frustrating to live with.

What are the Symptoms of a Perilymphatic Fistula?

Perilymphatic fistulas are associated with the sudden onset of severe vertigo, hearing loss, and loud ringing in the ear. These usually result from some form of trauma. While they are considered rare, they are not uncommon in motor vehicle collision injuries. Patients may report feeling or hearing their ear pop immediately before the onset of symptoms (2).

Dizziness and vertigo are the most common symptoms of a perilymphatic fistula. These symptoms may change based on the position of the head or body. High frequency hearing loss is common and may persist once the dizziness and vertigo resolve. Tinnitus, or ringing of the ear, is another common perilymphatic fistula symptom.

The disruption of membranes in the inner ear can create a unique kind of sound sensitivity known as the Tullio phenomenon. Patients can experience vertigo, blurry vision, balance difficulty, and drop attacks in response to loud sounds (13).

Chronic symptoms of PLF include a feeling of fullness in the affected ear, persistent nausea, motion sickness, a sensation of tilting to one side, headaches, and cognitive difficulties.

What Causes a Perilymphatic Fistula?

Trauma to the structures of the inner ear is the main cause of perilymphatic fistula. This trauma may at times be caused by changes in pressure, such as when flying or diving, however it is most commonly caused by an impact to the skull surrounding the inner ear (1).

Fistulas usually manifest as ruptured membranes of the inner ear called as the Round or Oval Windows. They may also occur in any fractured or damaged area of bone surrounding the inner ear. A frequent type of fistula is known as Superior Semicircular Canal Dehiscence Syndrome (SSCD). The vestibular system uses specific receptors known as semicircular canals to inform the brain of the head’s position in space and how it is moving. In SSCD, an area of thin bone atop the superior canal can fracture or degenerate. The loss of bone integrity creates a pressure gradient that causes membranes that were encased in bone to rupture, producing a fistula (12).

Direct trauma to the ear can cause a displacement of the stapes bone from the oval window of the cochlea. A congenital defect has also been discussed as a possible source of this condition. In other cases, a PLF may be the result of puncturing the eardrum, exposure to extremely loud sounds, ear infections, or even blowing your nose or sneezing hard. Perilymphatic fistulas may account for a considerable portion of patients with vertigo of unknown origin (2).

What are the Consequences of a Perilymphatic Fistula?

When a PLF develops, the symptoms are usually severe and disabling. Over a few weeks the torn membrane may heal spontaneously by forming scar tissue. This tissue will always be weaker than the membrane it replaced, and will render it vulnerable to future rupture. Many people experience recurrent fistulas, and need to be very careful with their activity to avoid another membrane tear. A PLF can recur when someone goes through an altitude change, when they lift something heavy, when they strain for a bowel movement, when they sneeze, or even when they laugh.

How is a Perilymphatic Fistula Diagnosed?

A PLF can be difficult to diagnose. The symptoms of PLF closely match Meniere’s Disease, a degenerative condition of the inner ear. They are treated entirely differently, so an accurate diagnosis is important.

A PLF can at times be identified by the presence of Hennebert’s sign, in which pressure is applied to the external ear canal resulting in a spontaneous eye movement known as nystagmus. PLF can be contrasted with Meniere’s disease through the use of electrocochleography testing, which can confirm the presence of increased fluid pressure in the inner ear (the opposite of which is seen in PLF).

In some cases, a PLF may be implied by a CT scan. Ultimately the only way to fully confirm the presence of a perilymphatic fistula is during surgical repair (12).

How is a Perilymphatic Fistula Typically Treated?

Most cases of acute PLF can be managed by bedrest and head elevation. Mild sedation can be appropriate to limit activities that may spike symptoms. A typical bedrest protocol involves lying down with the head elevated above the heart for 23 hours a day. Straining and hanging upside down should be avoided at all costs during bedrest, and stool softeners are often employed to limit straining (3). A PLF will often heal spontaneously within a few days or weeks.

In severe cases, or when bedrest is unsuccessful, surgery may be the only option for fistula closure. The improvement in symptoms following fistula closure surgery is often dramatic (12).

How is the NeuroRescue Program Different?

While fistulas are considered to be extremely rare, we see fistula patients on a relatively frequent basis. Our first order of business is to ensure that the PLF is allowed to close. We may recommend a bedrest protocol, or coordinate with one of the skull base surgeons we work with to facilitate surgical repair.

The unfortunate reality of living with a perilymphatic fistula is that over time the brain begins to adapt to the inappropriate signals from the inner ear as being the new normal. A PLF can be a hard condition to diagnose. It can take years of struggling with vertigo and nausea and seeing countless providers before an appropriate diagnosis is finally made. By that time the brain will have learned to partially compensate for the impaired vestibular reflexes. The brain and cerebellum have a wonderful capacity to adapt to changes in receptor inputs, but once a PLF is closed, the brain’s adaptive compensation may create as many problems as it originally solved.

While people generally describe marked improvement in their symptoms following fistula closure, in almost all cases there are residual sensations of dizziness, nausea, balance difficulty, and cognitive challenges that need to be addressed. These persistent symptoms often do not respond well to traditional visual and vestibular therapy. These are exactly the symptoms the NeuroRescue program can effectively address.

The therapies we will employ will be determined by the realities of your condition and your diagnostic testing findings. These may involve specific exercises to retrain the integration of your eyes and inner ear during head movement (4). It may involve specific forms of eye exercises to enhance your stability (5), or transcutaneous electrical stimulation to stimulate your vestibular system (6). It may involve specific types of visual stimulation exercises (7), or visual stimulation coupled with specific head movements (8). It may involve the use of transcranial magnetic stimulation to decrease your dizziness (9), or even the use of exercises performed in a virtual reality environment (10).

No two cases of perilymphatic fistula are alike, and the same holds true for the NeuroRescue Program. A cookie-cutter approach will be doomed to fail in a condition as complicated as perilymphatic fistula. All of our therapies are tailored to the specific realities of your case as determined by your unique diagnostic findings.

How does the NeuroRescue Program work?

We design your unique NeuroRescue Program to be among the most comprehensive diagnostic and therapeutic protocols available today. We create individual NeuroRescue Programs based on a comprehensive analysis of every relevant neurological system and pathway, using gold-standard, cutting edge neurodiagnostic technologies and examination procedures and state-of-the-art therapies.

We begin with your Discovery Day, wherein we perform a comprehensive history of not only your condition, but your life on a timeline. This allows us to dive deeply into your case and see all of the factors that led to where you are now. It helps us uncover hidden problems and associated conditions that may be making it difficult for you to move your recovery forward.

Our examination allows us to identify the areas and pathways of your brain that are involved in your perilymphatic fistula. In all of our cases of PLF, we begin by making certain that there are no central nervous system factors contributing to your symptoms. We do this by precisely quantifying the function of your visual, vestibular, and proprioceptive systems through computerized analysis of your eye movements, your inner ear reflexes, and your balance in a host of different sensory conditions.

We employ technologies including Videooculography and Saccadometry to measure several classes of eye movements. We use Video Head Impulse Testing to measure the function of your inner ear, and Computerized Dynamic Posturography to assess your balance in different sensory conditions.

We use NeuroSensoryMotor Integration testing to evaluate hand-eye coordination and cognition, and Virtualis testing to assess dynamic eye tracking and perception of vertical in a virtual reality environment.

We combine all of this with a comprehensive physical and neurological examination of your sensory, motor, autonomic, and cognitive systems. We review any relevant laboratory testing, radiological imaging, and prior neurodiagnostic testing, and integrate that information with our findings.

We use this information to identify which parts of your nervous system are working properly, which systems are struggling, and the precise point at which your systems fatigue.

We can then design a NeuroRescue Program that is unique and specific to your brain, and yours alone. Your NeuroRescue Program works to rejuvenate and reintegrate the damaged neurons and pathways in your central and peripheral nervous systems. It works to improve energy, endurance, and functional capacity within your involved fragile systems.

We use our technologies and procedures to not only see what we need to address, but also when it is time to stop and let you rest. We address your impaired neurological function from multiple angles of therapy, and provide metabolic support to improve neurological recovery.

While we cannot bring back neurons that have been lost, your NeuroRescue Program allows us to take the pathways that remain and maximize their efficiency and endurance. And by focusing on the integration of systems, we can do more than just get pathways working better, we can get them working together again. This gives us our best opportunity to return you to living a healthy, vibrant, and fulfilling life.