Perilymph fistula (PLF)

What is Perilymph fistula?

A perilymph fistula (PLF) is a break or defect in the membranes that divide the middle ear from the inner ear's perilymphatic region. Fluid may drain into the middle ear as a result of the tear. It can also induce pressure changes in the middle ear, which can affect the inner ear and generate abnormal symptoms.

A perilymph fistula (PLF) is a hole or tear in one of the membranes that separate your middle ear from your inner ear. Your middle ear contains air, whereas your inner ear contains fluid (perilymph). Membranes divide these two locations inside your ear. Perilymphatic fluid can leak from your inner ear into your middle ear if the membranes break. The pressure fluctuations that follow might cause balance and hearing issues.

Epidemiology of Perilymph fistula (PLF)

PLFs are ultimately an uncommon condition: the incidence of PLFs is believed to be 1.5/100,000 individuals, which is comparable to vestibular schwannoma. PLFs produced by congenital defects may be a more prevalent source of audio-vestibular symptoms (symptoms linked to hearing and balance) in children, with up to 6% of children suffering from idiopathic sensorineural hearing loss.

Difficulties in identifying and diagnosing PLFs have resulted in a scarcity of more reliable epidemiological data. Part of the issue has been that most approaches for identifying PLFs lacked the sensitivity and specificity needed to deliver consistent diagnosis. However, advances in imaging methods and upcoming technologies, like as biomarkers, have showed promise as tools for defining and diagnosing PLF.

Despite their rarity, PLFs are significant because they are one of the few probable causes of hearing loss and vestibular disturbance that may be surgically corrected.

 

What are the Causes of Perilymph fistula (PLF)?

PLFs are roughly classified into two types: those with a known etiology and those without. PLFs were originally identified in post-stapedectomy (stapes removal and prosthesis insertion) patients, when perilymph would leak around a prosthesis inserted into the oval window (opening in the membrane between the middle and inner ear) due to a breakdown of the seal surrounding or under the prosthesis.

Despite advances in stapes surgical techniques, PLFs still occur as a complication in 1% of stapedotomy surgeries and may be present in up to one-third of those who require revision stapedectomies. Shortly after surgery was recognized as a cause of PLFs, surgeons noticed that PLFs might be present even in the absence of a history of previous otologic surgery and attributed their origin to head trauma. Possible causes include barotrauma (rapid changes in pressure caused by flying, scuba diving, heavy lifting, and delivery), temporal bone fractures, and penetrating trauma.

Clinicians distinguished implosive (originating from Valsalva force-induced increased pressure in the middle ear) from explosive (originating from increased cerebrospinal fluid (CSF) pressure) forces as causes of inner ear damage in the 1970s. However, there were situations where people were discovered to exhibit PLF symptoms while having no history of surgery or trauma. The exact number of "spontaneous" or "idiopathic" PLF instances varies, although it may be considerable, ranging from 24 to 51 percent.

These episodes were occasionally preceded by a particular event, such as sneezing, straining, nose blowing, laughing, or even leaning over, raising the debate on what defines an idiopathic PLF. Congenital abnormalities and microfissure formation may play a role in some circumstances. Microfissures can form in a variety of locations in the temporal bone, but those that form between the round window niche and the posterior canal ampulla, as well as surrounding the oval window, are thought to be the cause of PLFs.

 

What are the Symptoms of Perilymph fistula?

Changes in air pressure that happen in the middle ear (for example, when your ears "pop" in an airplane) do not generally influence your inner ear. When a fistula is present, changes in middle ear pressure will directly influence the inner ear, activating the balance and/or hearing structures therein and producing PLF symptoms.

The inner ear's perilymphatic region is linked to the cerebrospinal fluid (CSF) that surrounds the brain. The composition of perilymphatic fluid, which is rich in sodium (Na+), is comparable to that of CSF. When there is an improper connection between the membranes of the middle and inner ear, perilymph in the inner ear exits and is replaced by CSF, which is driven by the hydrostatic pressure of the CSF. This can also lead to lower-than-normal amounts of CSF fluid surrounding the brain and spinal cord, which can cause symptoms like moderate headache.

A perilymph fistula can cause the following symptoms:

• A sensation of fullness in your ear
• Sudden hearing loss
• Intermittent hearing loss
• Dizziness or vertigo
• Persistent, moderate nausea
• Memory loss
• Motion sickness
• A sense of being imbalanced, frequently to one side
• Headaches
• Ringing in the ears

Ear fullness, fluctuating or "sensitive" hearing, dizziness without true vertigo (spinning), and motion intolerance are the most prevalent symptoms of a perilymph fistula. A PLF can cause vertigo or abrupt hearing loss. Most persons with fistulas report that changes in altitude (rapid elevators, flights, and travel across mountain passes) or increased CSF pressure caused by hard lifting, bending over, and coughing or sneezing aggravate their symptoms.

Some people have no symptoms, while others have modest symptoms that are barely detectable. Some individuals just report feeling "off." Remember that perilymph fistulas often affect just one ear at a time. In rare circumstances, significant head trauma might result in bilateral perilymph fistulas.

Patients with PLF are frequently dissatisfied and depressed because, while they do not feel well, they appear to others to be normal. PLF sufferers, in particular, and vestibular patients in general, sometimes struggle to explain their condition to friends and family. Sometimes just asking your support network for patience and understanding while you investigate diagnostic and treatment options and learn to manage with the symptoms of chronic dizziness is enough.

How is Perilymph fistula Diagnosed?

For decades, intra-operative observation of perilymph leakage with subsequent improvement in symptoms when the leak was corrected was the gold standard for diagnosing a PLF. This test, however, is somewhat subjective because there are no accepted criteria for what defines a perilymphatic leak on observation.

The necessity for exploratory techniques to find PLFs in traumatic or post-surgical situations has decreased as computed tomography (CT) and magnetic resonance imaging (MRI) resolution has improved. Pneumo-labyrinth, or air in the cochlea, vestibule, and/or semicircular canals, was one of the first radiological indicators of a PLF. Small air bubbles might be difficult to see on standard CT scans, but high-resolution scans may be beneficial in suspected situations. Another solid indicator of a PLF is fluid in the round and oval windows.

Other tests, including audiometry, cervical vestibular evoked myogenic potential (cVEMP), electrocochleography, and the fistula test, have been used to aid in the identification of PLFs. The use of biomarkers to identify perilymph fluid is also being investigated. Beta-2 transferrin and cochlin tomoprotein (CTP) have been studied as a possible technique to confirm perilymph leaking in the middle ear.

Symptoms of perilymph fistula are comparable to those of other inner ear diseases such Meniere's disease, vestibular neuritis, and labyrinthitis. As a result, it is critical that your healthcare professional rule out these other possibilities. They may suggest a variety of tests, including:

• Hearing tests.
• Balance tests.
• Electrocochleography, which monitors the fluid pressure inside the inner ear.
• A perilymph fistula test, which monitors your eye movements while applying pressure to your ear canal.

 

Proposed perilymph fistula (PLF) diagnostic criteria:

Definite PLF

Fluctuating or non-fluctuating hearing loss, tinnitus, ear fullness, and/or vestibular symptoms shortly preceding one of the following situations that meets Criteria A or B:

1. Barotrauma induced by external events (e.g., ear slap/suction, head trauma, explosion, skydiving, underwater diving, or flying, etc.).
2. Barotrauma as a result of internal processes (e.g., nose-blowing, sneezing, straining, or heavy lifting, etc.).
3. Direct damage to the inner ear (e.g., Q-tip injury, stapedotomy operation, temporal bone fracture, etc.).

A. Laboratory testing for a high sensitivity and specificity perilymph biomarker.

B. Perilymph leaking in the middle ear and remission of symptoms following therapy with an intratympanic blood patch or surgical leak sealing.

 

Possible PLF

Hearing loss, tinnitus, ear fullness, and/or vestibular symptoms without antecedent event, with third window abnormalities and lack of response to migraine lifestyle, dietary, and prophylaxis therapy, and with resolution of symptoms after treatment with intratympanic blood patch or surgical leak plugging.

 

What is Perilymph fistula Treatment?

PLF treatment is mainly divided into two categories: conservative and surgical. The therapeutic technique used is frequently determined by the etiology of the PLF and the severity of the symptoms. PLF with a known cause is often treated surgically; however, conservative treatment may be attempted if no identified explanation for the PLF symptoms is known (idiopathic PLF).

The patient is recommended to limit his or her physical activities for 7-14 days. Testing is recommended if the symptoms do not improve or plateau. If the results of the testing support the diagnosis of perilymph fistula, surgical intervention may be considered. Lifting, straining, and bending over should be avoided by those with confirmed fistulas who are awaiting surgery since these actions can aggravate the symptoms.

A blood patch injection, a relatively novel therapy, may also be beneficial. This might be used as a first-line therapy. This therapy entails injecting your own blood into your middle ear, which repairs the damaged window membrane. PLFs with a known etiology should typically be treated surgically to prevent future hearing loss. If conservative care fails, PLFs with no known etiology can be treated surgically.

There is evidence, notably in animal models, that certain PLFs can heal on their own if conditions that cause high intracranial/intracochlear pressure, such as straining, are avoided. The particular properties of PLFs that repair spontaneously have yet to be determined. Despite this, data tends to indicate that the more severe the initiating trauma, the less likely spontaneous healing is. Because research in this field is limited, it is hard to ascertain what percentage of patients improve with conservative therapy alone. Conservative therapy is typically not indicated in individuals with established causes of PLF, due to the danger of irreversible hearing loss if surgical treatment is delayed.

 

Patient preparation:

Patients are advised to have the operation performed in an ambulatory surgical environment under local anesthesia with monitoring anesthetic treatment. A general anesthesia might be considered if there are concerns about claustrophobia, anxiety, or difficulties positioning. For healthy young individuals, no preoperative laboratory work or testing is necessary; older patients and those with systemic disorders should receive testing as appropriate for their medical comorbidities.

Patients are recommended to stop taking aspirin and nonsteroidal anti-inflammatory drugs 10 to 14 days before surgery. When discontinuing anticoagulants such as warfarin or clopidogrel, clearance from the prescribing physician should be obtained. The night before surgery, patients are told to wash their hair. If graft material needs to be extracted, patients are advised that a tiny postauricular or tragal incision may be required. If a leak is discovered intraoperatively, patients must be kept in bed for 5 days with toilet privileges and must refrain from hard lifting, straining, or sexual activity for at least 2 weeks.

 

Perilymph fistula surgery:

There are several surgical treatment options available, ranging from in-office treatments to surgeries in a surgical theater, all with the objective of closing the fistula. Regardless of which window contains the fistula, both the oval and round windows are typically grafted with temporalis fascia or tragal perichondrium. Other materials that have been employed include fat grafts, areolar tissue, and Gel-foam.

A PLF repair is performed through the ear canal, sometimes under general anesthesia. The eardrum is raised, and small grafts are inserted at the base of the stapes (stirrup) and in the spherical window niche. The procedure normally takes 45-60 minutes to complete. There is minimal, if any, soreness. Some patients are hospitalized overnight in order to limit their activities.

The patient is recommended to spend three days at home with reduced exercise after being discharged. The patient may resume sedentary occupational activities after three days. For one month, the patient is recommended to avoid lifting more than 10 pounds and to refrain from participating in sports. After one month, additional limits on activities such as contact sports, diving, weight lifting, and roller coasters are indicated. All of these actions have resulted in recurring PLFs following a successful first repair.

Surgery is often effective in reducing or eliminating patient symptoms, with vestibular symptoms improving more frequently than auditory problems. Patients' vestibular symptoms improve in 80-95 percent of cases, whereas hearing problems improve in 20-49 percent of cases. The time of surgery is a debatable issue, some doctors advocate for fast corrective surgery within a few days after presentation, while others argue that early surgery is not necessarily essential because hearing benefits are minor.

Some surgeons noted that patients' hearing may benefit from surgery even after symptoms have been present for years, while others discovered that prognosis may be dependent on repair timing. The effectiveness and time of surgical correction are determined by the etiology and location of the PLF. When presenting to the office or the emergency room, an in-office blood patch treatment is indicated.

How long does Perilymph fistula take to heal?

While most individuals feel better within a few days, complete recovery might take several weeks. It is critical that you follow all post-operative instructions supplied by your surgeon at this period. In general, you should sleep with your head raised and avoid activities like diving and heavy lifting that can cause ear strain.

 

What are the Complications of Perilymph fistula surgery?

Complications of surgical correction of a perilymph fistula include:

• Tympanic membrane perforation
• Ear infection: Infection is a potential complication after any operation. This is quite uncommon following this procedure.
• Increased hearing loss: It is usual to experience impaired hearing for many days to weeks following this procedure. Permanent hearing loss is uncommon. If this procedure is done to treat hearing loss, it may take many weeks to observe any positive results.
• Paralysis associated with a facial nerve injury: The facial nerve, which travels through the ear, governs movement on one side of the face. Face paralysis is a fairly unusual complication of this treatment.
• Loss of sense of taste on the affected side: The middle ear contains the nerve that gives one-third of the flavor to the tongue. As a result, transitory taste disturbances can occur following this procedure but this is uncommon.
• Constant dizziness: Spinning vertigo may arise following this procedure and take many days to resolve. The results of this procedure will not be seen for several weeks.
• Ringing in the ear: Tinnitus (ringing in the ears) is common in people following this type of surgery. Ringing is normally reduced after surgery, although it might be severe and highly uncomfortable.

Diagnosis of perilymphatic fistula is difficult. Because of the growing awareness of illnesses such as canal dehiscence and vestibular migraine, which have symptoms similar to perilymphatic fistula, many patients can now be treated adequately without middle-ear investigation. As a result, one typical "complication" associated with the therapy of perilymphatic fistula is that the diagnosis was made incorrectly.

The most significant risk of surgery for perilymphatic fistula is that middle-ear exploration may fail to reveal a fistula or that the symptoms of the fistula may not be entirely healed following therapy.

Failures of fistula surgery must first and foremost be addressed by reviewing the diagnosis, which is based in part on whether a true leak was discovered during the first operation. If this is not the case, the diagnosis of vestibular migraine must be carefully evaluated, and imaging for canal dehiscence or an enlarged vestibular aqueduct should be performed. Reoperation may obviously help certain patients by ensuring that muscle and fascia are used to plug the leak rather than more easily resorbable fat.

 

How can Perilymph fistula be Prevented?

While you won't be able to completely avoid PLFs, you may take efforts to lower your risk. As an example:

• Wear earplugs when you know you'll be exposed to loud noise.
• When traveling by plane, use filtered earplugs. This may aid in the equalization of pressure in your ears.
• If you have a history of recurring ear infections, see your doctor about prophylactic measures. 

What is the Prognosis of Perilymph fistula?

If you have symptoms such as balance problems or dizziness, you may need to make modifications to your daily routine. For example, if walking around triggers your symptoms, then have someone else run errands for you. Additionally, avoid situations in which you might lose your balance and fall.

Some PLFs can heal on their own with adequate rest. However, in some cases, blood patch injections or surgery may be necessary.

 

Conclusion

A perilymph fistula (PLF) is a rupture or defect in the membranes that separate the middle ear from the perilymphatic area of the inner ear. As a result of the rip, fluid may flow into the middle ear. Perilymph Fistulas are typically a rare condition affecting about 1.5/100,000 of individuals.

Perilymphatic fistulas are caused by a variety of reasons, including:

• Head trauma.
• Ear trauma.
• Ear surgery.
• Barotrauma.
• A punctured eardrum.
• Exposure to loud noises near to your ear, such as gunshots.
• Recurrent ear infections.
• Excessively blowing your nose.

A perilymphatic fistula may appear to form for no obvious reason at times. However, it is frequently the result of an earlier injury that did not create obvious symptoms.

Perilymphatic fistulas can cause a variety of distressing symptoms that impair your quality of life. Including:

• A sensation of fullness in your ear
• Sudden hearing loss
• Intermittent hearing loss
• Dizziness or vertigo
• Persistent, moderate nausea
• Memory loss
• Motion sickness
• A sense of being imbalanced, frequently to one side
• Headaches
• Ringing in the ears

If you have a PLF, your doctor may advise you to stay in bed as much as possible to allow the fistula to heal on its own. If bed rest is insufficient, you may require surgery. It is critical that you strictly adhere to the instructions provided by your healthcare practitioner in order to recover as rapidly as possible.