Perilymphatic Fistula: Symptoms, Types, Causes and Treatment

Perilymphatic fistula (PLF) is a fascinating yet challenging disorder of the inner ear that can lead to a range of hearing and balance problems. Despite being recognized for over a century, PLF remains a topic of clinical debate due to its elusive diagnosis and variable presentation. For patients, understanding the symptoms, types, causes, and treatment options is crucial for timely intervention and improved quality of life. In this article, we explore the current knowledge about PLF, synthesizing evidence from recent research to provide a comprehensive overview.

Symptoms of Perilymphatic Fistula

PLF presents with a mix of auditory and vestibular symptoms, which can be subtle or dramatic. Recognizing these symptoms is essential for early diagnosis and effective treatment, as many of them overlap with other inner ear disorders. Patients may experience sudden or fluctuating hearing loss, persistent dizziness, balance disturbances, tinnitus, and sometimes pressure or fullness in the ear. These symptoms can develop abruptly after trauma or gradually over time, making clinical suspicion critical.

Symptom	Description	Frequency/Notes	Source(s)
Hearing Loss	Sudden, fluctuating, or progressive	Often sensorineural, sometimes mixed	1 3 4 5 6 7
Vertigo/Dizziness	Spinning sensation or imbalance	Persistent or episodic; worsened by exertion	1 3 4 5 6 7
Tinnitus	Ringing or buzzing in the ear	May accompany hearing loss	1 5 6 7 11
Aural Fullness	Sensation of ear pressure	Less common, but reported	5 6 11
Nystagmus	Involuntary eye movements	Often positional; multiple canal involvement	3 5
Fistula Sign	Symptoms triggered by pressure	Positive fistula test, Hennebert sign	5 6

Table 1: Key Symptoms

Hearing and Auditory Symptoms

The most consistent symptom in PLF is hearing loss. This can be sudden, fluctuate with changes in pressure, or progressively worsen. Both sensorineural and mixed (conductive plus sensorineural) hearing loss have been reported, with lower-frequency loss being especially notable in some patients 3 4 5 7. Tinnitus—ringing or buzzing in the ear—is also commonly described and often accompanies hearing loss 1 5 6 11.

Vestibular and Balance Disturbances

Vertigo and persistent dizziness are hallmark symptoms, sometimes mimicking post-concussion syndrome or other vestibular pathologies 1 3 4 5 7. Dizziness may persist for months or years if the fistula remains unrecognized 1. Nystagmus, particularly positional and involving multiple semicircular canals, is frequently observed and tends to resolve after surgical treatment 3.

Other Clinical Signs

Aural fullness or a sensation of ear pressure is another symptom, though less frequently reported 5 6. The “fistula sign”—worsening symptoms with changes in pressure or straining (e.g., Valsalva maneuver)—can provide a diagnostic clue. The Hennebert sign, where pressure on the tragus induces symptoms, may also be present 5 6.

Types of Perilymphatic Fistula

PLF is not a one-size-fits-all diagnosis. It encompasses several types, distinguished by location, cause, and anatomical features. Understanding these distinctions helps clinicians tailor diagnosis and management.

Type	Description/Anatomy	Typical Onset/Population	Source(s)
Traumatic	Follows head or ear injury	Sudden, any age	1 2 4 7 11
Congenital	Structural abnormality present	Often in children, detected early	2 7 10
Spontaneous	No clear cause (idiopathic)	Adults, sometimes bilateral	2 7 12
Postsurgical	After ear surgery (e.g. stapes)	History of otologic procedure	2 7 11
Iatrogenic	Due to medical intervention	Linked to treatment/procedures	2 7

Table 2: Types of Perilymphatic Fistula

Traumatic PLF

Traumatic fistulas are the most common type, typically resulting from blunt head trauma, barotrauma (sudden pressure changes), or penetrating injury to the ear. Temporal bone fractures and blast injuries are classic causes 1 2 4 7 11. Symptoms usually begin abruptly after the event.

Congenital PLF

Congenital PLFs arise from developmental anomalies of the inner ear structures, such as malformed oval or round windows, or ossicular chain abnormalities. These are often recognized in infants or children presenting with unexplained, progressive, or fluctuating hearing loss and balance issues 2 7 10. Otitis media can unmask or exacerbate congenital PLFs 10.

Spontaneous (Idiopathic) PLF

This type occurs without a known precipitating factor. It remains controversial, as symptoms are often ambiguous and overlap with other disorders 2 7 12. Spontaneous PLFs may affect both ears and can be difficult to diagnose without surgical exploration.

Postsurgical and Iatrogenic PLF

PLF can occur as a complication of ear surgeries, such as stapedectomy, or other medical interventions involving the temporal bone 2 7 11. Awareness of this risk is important in postoperative patients who develop new hearing or balance symptoms.

Causes of Perilymphatic Fistula

PLF is fundamentally caused by an abnormal communication between the perilymph-filled inner ear and the air-filled middle ear or cranial spaces. The initiating event or condition varies widely, but all lead to leakage of perilymph, disrupting the delicate balance of inner ear fluids and pressure.

Cause	Mechanism/Trigger	Risk Group/Setting	Source(s)
Head Trauma	Fractures, blunt injury	Accidents, sports	1 2 4 7 11
Barotrauma	Sudden pressure changes	Diving, air travel, sneezing	2 7 9 14
Congenital Defect	Malformation of windows/bones	Infants, children	2 7 10
Ear Surgery	Intraoperative injury	Otologic patients	2 7 11
Chronic Inflammation	Erosion from infection	Chronic ear disease	2 7 10 11
Idiopathic	No clear cause	Adults (often spontaneous)	2 7 12
Iatrogenic	Medical intervention	After procedures	2 7

Table 3: Causes of Perilymphatic Fistula

Traumatic and Barotraumatic Causes

Most PLFs are due to trauma—either direct (blunt force, fractures) or secondary to pressure changes (barotrauma). Activities such as diving, air travel, heavy lifting, or even sneezing can generate enough force to rupture the oval or round window membranes 1 2 4 7 9 14.

Congenital Anomalies

Structural malformations of the inner ear windows or ossicles are a significant cause in children. These defects may remain silent until minor trauma, infection, or increased intracranial pressure triggers symptoms 2 7 10. Children with syndromic features or recurrent otitis media are at higher risk 10.

Postsurgical, Iatrogenic, and Inflammatory Causes

Ear surgeries and some medical interventions can inadvertently create a fistula, particularly during or after stapedectomy or other temporal bone procedures 2 7 11. Chronic middle ear inflammation can also erode the protective barriers, leading to a PLF 2 7 10 11.

Idiopathic Cases

Some cases arise without any identifiable cause. These are diagnosed by exclusion after ruling out trauma, congenital defects, and other secondary causes 2 7 12. The true incidence of idiopathic PLF is unknown and remains controversial.

Treatment of Perilymphatic Fistula

Management of PLF depends on the severity of symptoms, underlying cause, and the promptness of diagnosis. Treatment aims to prevent ongoing perilymph leakage, preserve or restore hearing, and resolve vestibular symptoms. Both conservative and surgical approaches are used, often tailored to the individual patient.

Treatment	Approach/Method	Indication/Outcome	Source(s)
Conservative	Bed rest, head elevation, steroid	Mild/moderate, recent onset	5 14
Blood Patch	Intratympanic blood injection	Alternative to surgery	14
Surgical Repair	Sealing oval/round window	Persistent, severe, confirmed	1 2 3 4 6 7 9 12
Imaging & Diagnostics	CT, MRI, vestibular tests	Pre-surgical assessment	2 5 6 8
Shunt Procedures	VP shunt for refractory cases	When conventional fails	13
Adjunct Therapies	Steroids, shunt, ablation	Selected cases, symptom control	12 13

Table 4: Treatment Approaches

Conservative Management

Initial treatment for mild or recent-onset symptoms often includes bed rest, head elevation, avoidance of straining, and sometimes corticosteroids. This approach is generally reserved for cases where symptoms are not severe or are improving 5 14. Many patients improve without surgery, especially if the fistula is small.

Intratympanic Blood Patch

A newer, less invasive approach involves injecting the patient's own blood into the middle ear to seal the leak. This method has shown promising results, offering faster symptom resolution, reduced costs, and avoidance of surgery in selected patients 14.

Surgical Repair

For persistent, severe, or surgically confirmed PLFs, direct repair is the gold standard. Surgery typically involves exploration of the middle ear and reinforcement or sealing of the oval and/or round window with tissue grafts or other materials 1 2 3 4 6 7 9 12. Early surgical intervention improves the likelihood of hearing recovery and resolution of vestibular symptoms 6 9. Surgical outcomes are often good, especially for dizziness and positional nystagmus 3 4.

Diagnostic Tools and Imaging

Accurate diagnosis is critical before committing to surgery. Audiometry, electronystagmography, vestibular assessments, and imaging (CT, MRI) are used to identify the site and extent of the fistula 2 5 6 8. New biomarkers, such as Cochlin-tomoprotein (CTP), are being explored as diagnostic aids 2.

Shunt Procedures and Adjunct Therapies

In rare, refractory cases where conventional treatments fail, ventriculoperitoneal (VP) shunt insertion may help by reducing intracranial and perilymphatic pressure, allowing the fistula to heal 13. Other adjuncts, such as labyrinthectomy or cochlear aqueduct blocking, may be considered in complex cases 12 13.

Conclusion

Perilymphatic fistula is a complex but potentially treatable cause of hearing loss and dizziness. Early recognition and tailored management are key to optimizing outcomes. Here’s a summary of the main points:

• PLF commonly causes hearing loss, vertigo, tinnitus, and sometimes nystagmus or aural fullness.
• Types include traumatic, congenital, spontaneous (idiopathic), postsurgical, and iatrogenic forms.
• Causes range from head trauma and barotrauma to congenital defects and surgical complications.
• Treatment includes conservative measures, intratympanic blood patch, and surgical repair, with emerging options for refractory cases.
• Accurate diagnosis relies on a combination of clinical suspicion, audiovestibular testing, imaging, and sometimes surgical exploration.
• Early intervention can significantly improve hearing and balance, enhancing patients’ quality of life.

If you suspect PLF in yourself or someone you know—especially after trauma or sudden hearing changes—seeking prompt evaluation by an inner ear specialist is essential for the best possible recovery.