Did your dizziness begin after a flight, scuba diving, a blow to the head, heavy lifting or forceful straining?
Does coughing, sneezing, blowing your nose or changing pressure make you dizzy?
Perhaps your symptoms began suddenly with a feeling of pressure in one ear, hearing changes, tinnitus and disequilibrium—and have never quite settled.
One condition that may need to be considered in this situation is a Perilymphatic Fistula (PLF).
A Perilymphatic Fistula is an abnormal communication between the fluid-filled inner ear and an adjacent space, most commonly the air-filled middle ear. It can potentially produce both hearing and balance symptoms, including hearing loss, aural fullness, vertigo, disequilibrium and sensitivity to changes in pressure.
PLF is an important but challenging vestibular diagnosis. Unlike conditions such as BPPV, there is no single simple bedside test that reliably confirms or excludes a fistula. Symptoms can overlap with several other vestibular disorders, and even specialist diagnostic testing is not always definitive.
For this reason, the history surrounding the onset of symptoms is particularly important.
What is a Perilymphatic Fistula?
To understand a Perilymphatic Fistula, it helps to understand some basic inner-ear anatomy.
The inner ear contains two major sensory systems:
- The cochlea, responsible for hearing
- The vestibular system, responsible for balance and detecting head movement
These structures contain specialised fluids, including perilymph.
The inner ear is normally separated from the air-filled middle ear.
Two particularly important interfaces are the:
- Oval window
- Round window
The oval window interfaces with the stapes bone of the middle ear and allows sound energy to enter the inner ear.
The round window allows pressure created by this movement to dissipate appropriately within the cochlea.
A Perilymphatic Fistula can occur when an abnormal opening develops between the perilymph-containing inner ear and an adjacent space.
This can alter inner-ear mechanics and potentially allow perilymph to escape.
The result can be disruption of both hearing and vestibular function.
Where does a Perilymphatic Fistula occur?
The oval and round windows are commonly implicated sites.
PLFs can also occur in association with abnormalities or injury elsewhere within the bony labyrinth.
The location and mechanism can vary depending on whether the fistula has developed following trauma, barotrauma, ear surgery, congenital abnormality or another process.
This is one reason PLF is not always straightforward to diagnose.
What causes a Perilymphatic Fistula?
A PLF may occur following an identifiable event.
Potential causes include:
Head trauma
A direct blow to the head can potentially disrupt structures separating the middle and inner ear.
Symptoms may begin immediately after the injury or develop over the following days.
Barotrauma
Rapid or significant changes in pressure are particularly relevant.
Examples include:
- Scuba diving
- Air travel
- Blast injuries
- Rapid altitude changes
Forceful straining
Events that substantially increase intracranial or middle-ear pressure have historically been associated with PLF.
Examples can include:
- Heavy lifting
- Forceful straining
- Forceful nose blowing
- Coughing
- Sneezing
- Valsalva manoeuvres
This doesn’t mean that every person who becomes dizzy after sneezing has a fistula.
The overall clinical presentation is what matters.
Ear surgery
PLF can occur following certain otological procedures, particularly procedures involving the stapes.
A new onset of hearing loss or vestibular symptoms following ear surgery therefore warrants appropriate specialist assessment.
Penetrating ear trauma
Trauma involving the tympanic membrane and middle ear can potentially damage structures around the oval or round window.
Chronic middle-ear disease
Conditions such as cholesteatoma can erode the bone surrounding the inner ear and potentially produce a labyrinthine fistula.
Congenital inner-ear abnormalities
Certain anatomical abnormalities may predispose an individual to abnormal communication between inner-ear and surrounding structures.
No obvious cause
Importantly, not everyone with a suspected PLF remembers an obvious injury or pressure event.
Some cases are described as idiopathic or spontaneous.
What does a Perilymphatic Fistula feel like?
PLF can produce both auditory and vestibular symptoms.
Symptoms vary significantly between patients.
Some patients predominantly experience dizziness and imbalance.
Others notice hearing changes.
Some experience both.
Potential symptoms include:
- Vertigo
- Disequilibrium
- Persistent unsteadiness
- Motion intolerance
- Hearing loss
- Fluctuating hearing
- Aural fullness
- Tinnitus
- Autophony
- Sound-induced dizziness
- Pressure-induced dizziness
- Nausea
- Difficulty walking
- Feeling as though the environment moves with pressure changes
One of the important clues is the relationship between symptoms and pressure.
Pressure-induced dizziness
Pressure sensitivity is an important feature that can raise suspicion of PLF.
A patient may notice that dizziness or vertigo becomes worse when:
- Coughing
- Sneezing
- Straining
- Lifting
- Blowing their nose
- Performing a Valsalva manoeuvre
- Experiencing changes in atmospheric pressure
A patient may say:
“Every time I cough hard, I suddenly feel dizzy.”
or:
“My ear popped during the flight and immediately afterwards I developed dizziness and hearing loss.”
That type of history warrants further investigation.
Can loud noises cause dizziness with PLF?
They can.
Some patients experience dizziness or nystagmus in response to loud sound, known as the Tullio phenomenon.
However, this finding is not specific to Perilymphatic Fistula.
Sound-induced dizziness is particularly associated with other third-window disorders, including Superior Semicircular Canal Dehiscence Syndrome (SCDS).
Therefore, sound-induced vertigo should prompt careful differential diagnosis rather than automatically being labelled a PLF.
What hearing symptoms occur?
Hearing changes can be an important part of the presentation.
A patient may notice:
- Sudden hearing loss
- Fluctuating hearing
- A blocked sensation
- Aural fullness
- Sound sensitivity
- Tinnitus
- Changes in sound quality
The hearing loss may be sensorineural, conductive-appearing or mixed depending on the underlying anatomy and mechanism.
A sudden new sensorineural hearing loss requires urgent medical/ENT assessment, regardless of whether a PLF is suspected.
Does PLF cause tinnitus?
Tinnitus can occur, although it is not present in every patient.
Some patients describe roaring tinnitus around the onset of symptoms.
Others predominantly notice aural fullness or hearing change.
What is autophony?
Autophony describes an unusually loud perception of your own voice or internally generated sounds.
It can occur with PLF, although it is also associated with other conditions, particularly third-window disorders and Patulous Eustachian Tube dysfunction.
Again, the presence of autophony doesn’t diagnose a PLF by itself.
Can a Perilymphatic Fistula cause constant imbalance?
Yes.
Not every patient experiences dramatic attacks of rotational vertigo.
Some people primarily describe:
- Persistent disequilibrium
- Feeling off balance
- Motion sensitivity
- Difficulty walking
- Reduced confidence on their feet
- Symptoms aggravated by exertion or pressure
This can make PLF difficult to differentiate from other vestibular disorders.
Why can PLF be difficult to diagnose?
This is one of the most important aspects of Perilymphatic Fistula.
There is no universally accepted, perfectly reliable non-invasive diagnostic test for PLF.
Many of its symptoms overlap with other conditions.
A patient with dizziness, tinnitus, hearing changes and aural fullness could potentially have:
- Ménière’s Disease
- Vestibular Migraine
- Labyrinthitis
- BPPV occurring alongside another disorder
- Superior Semicircular Canal Dehiscence
- Another third-window disorder
- Vestibular hypofunction
- A traumatic inner-ear injury
- PLF
Even visualisation during surgery is not necessarily a perfect reference standard because a leak can be intermittent and tiny quantities of fluid can be difficult to identify.
Diagnosis therefore requires careful integration of the history, clinical examination, audiological findings, vestibular testing and imaging.
What historical clues make us suspicious of PLF?
The history can be extremely valuable.
A clinician may be more suspicious when a patient describes:
“My symptoms started immediately after scuba diving.”
“I was completely well until I had a significant blow to my head.”
“My ear popped on the plane and suddenly I couldn’t hear properly and became dizzy.”
“I lifted something extremely heavy and immediately developed vertigo and ear pressure.”
“Ever since the injury, coughing and straining make me dizzy.”
The combination of an identifiable precipitating event, auditory symptoms and pressure-sensitive vestibular symptoms can increase clinical suspicion.
What bedside tests can a Vestibular Physiotherapist perform?
A comprehensive vestibular examination is useful, although no bedside test can definitively rule PLF in or out.
The examination also helps identify other causes of dizziness.
Oculomotor examination
A general vestibular assessment may include:
- Smooth pursuit
- Saccades
- Gaze holding
- Observation for spontaneous nystagmus
- Eye alignment
These tests aren’t specifically diagnostic of PLF but form part of the broader vestibular and neurological examination.
Bedside Head Impulse Test
The Bedside Head Impulse Test assesses the Vestibulo-Ocular Reflex.
The patient looks at a stationary target while the clinician performs small, rapid head movements.
If vestibular hypofunction has occurred, a corrective saccade may be observed.
A normal Head Impulse Test does not exclude PLF.
Head-shake testing
Head-shake testing can help identify asymmetry within the vestibular system.
Again, an abnormal test may indicate vestibular dysfunction but is not specific for PLF.
Positional testing
Dix–Hallpike and Supine Roll testing should often form part of the assessment.
Why?
Because BPPV is considerably more common than PLF and can occur after head trauma.
A person may therefore develop positional vertigo following an injury and understandably assume something has been permanently damaged.
If Dix–Hallpike testing demonstrates characteristic positional nystagmus, BPPV may provide a much simpler explanation.
Conversely, repeatedly negative positional testing in someone whose symptoms are clearly pressure-provoked may lead the clinician to investigate other possibilities.
What is the fistula test?
The fistula test is one of the traditional bedside tests associated with PLF.
Pressure is applied to the external auditory canal, either manually or using pneumatic otoscopy, while the clinician observes the patient’s eyes and asks about symptoms.
A positive response may produce:
- Dizziness
- Vertigo
- Nystagmus
- Disequilibrium
Pressure applied to the external ear is transmitted through the tympanic membrane and middle ear.
If there is an abnormal communication with the inner ear, this pressure may stimulate vestibular structures and provoke symptoms.
However, there is an important limitation:
A negative fistula test does not exclude a Perilymphatic Fistula.
Published estimates of the sensitivity of the fistula sign vary widely, making it a supportive rather than definitive test.
What is Hennebert’s sign?
Hennebert’s sign refers to nystagmus induced by pressure changes within the external auditory canal despite an intact tympanic membrane.
It may occur in PLF but can also occur with other inner-ear conditions.
Therefore, it needs to be interpreted in context.
What is the Tullio phenomenon?
The Tullio phenomenon refers to dizziness, vertigo or nystagmus provoked by sound.
It may be assessed clinically by observing eye movements during an appropriate sound stimulus.
A positive Tullio phenomenon indicates abnormal sound-induced vestibular activation but does not specifically diagnose PLF.
Superior Canal Dehiscence and other third-window disorders must also be considered.
What vestibular testing may be performed?
More comprehensive vestibular investigation may include:
Videonystagmography or Electronystagmography
VNG/ENG can objectively record eye movements and identify spontaneous, positional or provoked nystagmus.
Pressure- or sound-induced nystagmus may sometimes be captured during testing.
Video Head Impulse Testing
vHIT provides objective assessment of the Vestibulo-Ocular Reflex across the semicircular canals.
It can help determine whether vestibular hypofunction is present.
However, vHIT does not diagnose PLF by itself.
VEMP testing
Vestibular Evoked Myogenic Potentials may also be performed.
VEMP responses can be altered in PLF, but these findings are not specific.
Reduced VEMP thresholds are particularly important in the differential diagnosis of third-window disorders such as Superior Semicircular Canal Dehiscence.
Therefore, an abnormal VEMP result must be interpreted together with audiometry, imaging and the patient’s symptoms.
Posturography
Computerised Dynamic Posturography can quantify balance impairment and sensory integration.
It may also demonstrate changes in postural sway when pressure is applied to the ear.
Again, this is supportive rather than definitive.
What hearing tests are required?
A comprehensive audiological assessment is particularly important if PLF is suspected.
This may include:
- Pure-tone audiometry
- Bone-conduction testing
- Speech testing
- Tympanometry
- Acoustic reflex testing
The purpose is to determine whether hearing loss is present and whether it appears conductive, sensorineural or mixed.
Serial audiograms can also be useful if hearing is fluctuating.
What is Electrocochleography?
Electrocochleography (ECochG) measures electrical activity generated by the cochlea and auditory nerve in response to sound.
Abnormalities can sometimes occur with PLF.
However, ECochG abnormalities can also occur in other inner-ear disorders, particularly Ménière’s Disease/endolymphatic hydrops.
It is therefore another piece of the diagnostic puzzle rather than a stand-alone diagnostic test.
Can a CT scan diagnose a Perilymphatic Fistula?
Imaging can be extremely helpful in selected cases, particularly following trauma.
A high-resolution CT scan of the temporal bones can identify abnormalities such as:
- Pneumolabyrinth
- Temporal bone fracture
- Stapes/ossicular abnormalities
- Cholesteatoma-related erosion
- Congenital inner-ear abnormalities
- Other third-window abnormalities
One particularly important finding is pneumolabyrinth.
What is pneumolabyrinth?
Pneumolabyrinth means that air has entered the fluid-filled inner ear.
Air should not normally be present within the vestibule, cochlea or semicircular canals.
When pneumolabyrinth is demonstrated on CT in the appropriate clinical context, it provides strong evidence of an abnormal communication with the inner ear.
However, most suspected PLFs do not necessarily demonstrate obvious pneumolabyrinth.
Therefore, a normal CT does not automatically exclude a small PLF.
What about MRI?
MRI may complement CT in selected patients.
MRI can provide additional information about soft tissues and fluid within the inner ear and can help investigate alternative causes of auditory and vestibular symptoms.
Research examining surgically confirmed PLF has suggested that combining CT and MRI can improve diagnostic performance in selected cases, particularly when assessing the oval and round window niches.
However, there remains no simple scan that can reliably identify every PLF.
Can a scan be completely normal?
Yes.
A very small or intermittent fistula may not be visible on routine imaging.
This is one reason diagnosis remains controversial and challenging.
A normal CT or MRI therefore needs to be interpreted alongside the clinical history and other testing.
At the same time, clinicians should be cautious about diagnosing PLF simply because imaging is normal and symptoms are unexplained.
Other vestibular diagnoses need to be appropriately considered.
Are there laboratory tests for PLF?
There has been considerable interest in identifying biomarkers that specifically indicate the presence of perilymph.
One of the most promising is Cochlin-tomoprotein (CTP).
CTP is a protein found in perilymph, and testing middle-ear fluid for CTP has been incorporated into diagnostic approaches in Japan.
This is not a routine test available in every country or vestibular clinic, but it represents an important development because historically clinicians have lacked a reliable biochemical marker for perilymph leakage.
Other potential biomarkers have also been investigated, although their clinical usefulness remains variable.
Is exploratory surgery used to diagnose PLF?
In selected cases, an ENT surgeon or Neuro-Otologist may perform an exploratory tympanotomy.
This allows direct inspection of the oval and round window regions.
If leakage is identified, the area can potentially be repaired at the same procedure.
However, even this is not a perfect diagnostic test.
A tiny fistula may not be actively leaking at the exact time of surgery, and distinguishing small amounts of perilymph from other fluid can be difficult.
This illustrates why PLF has historically been such a challenging and sometimes controversial diagnosis.
How is a Perilymphatic Fistula treated?
Management depends on the cause, severity and duration of symptoms and whether hearing is deteriorating.
Treatment may be conservative or surgical.
Conservative management
Some suspected PLFs may heal spontaneously.
Conservative management may initially involve avoiding activities that substantially increase intracranial or inner-ear pressure.
This can include temporarily avoiding:
- Heavy lifting
- Straining
- Forceful nose blowing
- Valsalva manoeuvres
- Diving
- Other provocative pressure changes
Medical guidance is important because the appropriate restrictions depend on the individual situation.
Historically, bed rest and head elevation have also been used during conservative management.
What is an intratympanic blood patch?
An intratympanic blood patch is a treatment sometimes used in suspected PLF.
A small amount of the patient’s own blood is introduced into the middle ear.
The intention is for the blood and subsequent inflammatory response to help seal the suspected oval or round window leak.
Some patients experience significant improvement following a blood patch, although symptoms can recur and not everyone responds.
This is an ENT/otological procedure rather than a Vestibular Physiotherapy treatment.
Surgical repair
Persistent or significant PLFs—particularly those associated with a clear traumatic or surgical cause, progressive hearing loss or disabling vestibular symptoms—may require surgical management.
The surgeon can reinforce or seal the oval and/or round window using appropriate graft material.
Surgery tends to be more consistently effective for vestibular symptoms than for restoring established hearing loss.
For this reason, significant or sudden hearing deterioration warrants prompt medical assessment.
What is the role of Vestibular Physiotherapy?
Vestibular Physiotherapy can play an important role in the assessment and recovery of patients with suspected or treated PLF.
However, there is a critical distinction:
Vestibular Physiotherapy cannot mechanically close an active Perilymphatic Fistula.
If there is ongoing leakage or an unstable inner-ear injury, repeatedly provoking symptoms through aggressive exercise may be inappropriate.
The first priority is determining whether the suspected fistula requires medical or surgical management.
Once the condition is medically stable, Vestibular Physiotherapy can become very useful.
1. Identifying whether another vestibular condition is present
A Vestibular Physiotherapist can assess whether symptoms might instead—or additionally—represent:
- BPPV
- Vestibular hypofunction
- Vestibular Migraine
- Visual motion sensitivity
- PPPD
- Another vestibular disorder
This is particularly important after head trauma because multiple vestibular conditions can occur simultaneously.
2. Assessing residual vestibular hypofunction
Following a PLF or its repair, some patients may be left with reduced vestibular function.
Assessment may identify:
- Abnormal Head Impulse Testing
- Reduced gaze stability
- Difficulty with head movements
- Impaired balance
- Increased reliance on vision
- Difficulty walking in darkness
- Motion sensitivity
Rehabilitation can then target these specific impairments.
3. Gaze-stability rehabilitation
If vestibular hypofunction is present and the fistula is considered medically stable, gaze-stability exercises may be prescribed.
These exercises train the Vestibulo-Ocular Reflex and help the brain maintain clear vision during head movement.
For example, the patient may focus on a stationary target while moving their head horizontally or vertically.
The speed, duration and complexity are gradually progressed according to the individual’s findings and tolerance.
4. Balance retraining
Patients with residual disequilibrium may benefit from exercises challenging the interaction between:
- Vision
- Vestibular input
- Proprioception
Exercises may involve:
- Narrowing the base of support
- Changing the surface
- Reducing visual input
- Walking with head movements
- Negotiating uneven surfaces
- Dynamic balance activities
These exercises should be individually prescribed.
5. Habituation and motion sensitivity
Following weeks or months of dizziness, some people become extremely sensitive to movement.
Once an active fistula has been appropriately managed, carefully graded habituation may help the nervous system become less reactive to safe movements.
The key word is graded.
The aim is not to repeatedly provoke severe vertigo or pressure-related symptoms.
6. Visual motion sensitivity
Some patients develop secondary sensitivity to:
- Supermarkets
- Crowds
- Scrolling
- Computer screens
- Moving traffic
- Busy visual environments
If the underlying PLF has been treated or stabilised, visual-motion rehabilitation may form part of the recovery program.
7. Postoperative Vestibular Rehabilitation
Vestibular Physiotherapy can be particularly valuable following surgical repair when residual dizziness or imbalance persists.
Rehabilitation may address:
- Walking
- Balance
- Head-movement tolerance
- Gaze stability
- Sensory integration
- Motion sensitivity
- Confidence with movement
- Return to work
- Return to exercise
The program should be coordinated with the treating surgeon and progressed according to postoperative restrictions.
Should I perform vestibular exercises if an active PLF is suspected?
This requires caution.
If a patient has recently developed significant pressure-sensitive dizziness and hearing changes following trauma, barotrauma or another clear precipitating event, the priority should be appropriate medical assessment, not simply prescribing exercises that repeatedly provoke the symptoms.
Activities involving significant straining or pressure changes may need to be avoided while the condition is being investigated.
Vestibular rehabilitation becomes most useful once the treating medical team is satisfied that the inner ear is stable or following appropriate repair.
When should I seek urgent assessment?
Seek prompt medical assessment if you experience:
- Sudden hearing loss
- Significant hearing deterioration following trauma
- Severe vertigo following head trauma
- New vertigo and hearing loss after diving
- Significant symptoms following barotrauma
- Severe symptoms following penetrating ear trauma
- New neurological symptoms
- Severe inability to walk
- Double vision
- Facial weakness
- Difficulty speaking
- Severe new headache
Sudden sensorineural hearing loss is particularly time-sensitive and should not simply be observed at home under the assumption that it is a fistula.
When should PLF be considered?
A Perilymphatic Fistula may warrant consideration when there is a combination of:
An appropriate precipitating event
such as head trauma, barotrauma, ear surgery or significant pressure change,
plus auditory symptoms
such as hearing loss, fluctuating hearing or aural fullness,
plus vestibular symptoms
such as vertigo or disequilibrium,
particularly when symptoms are aggravated by:
- Coughing
- Sneezing
- Straining
- Pressure changes
- Heavy lifting
- Sound
This pattern does not confirm PLF, but it provides a strong reason for further investigation.
Perilymphatic Fistula assessment and Vestibular Physiotherapy in Melbourne
At The Vertigo Co, we assess patients experiencing vertigo, dizziness, imbalance and complex vestibular presentations.
When a patient presents with symptoms suspicious for Perilymphatic Fistula, a comprehensive vestibular assessment can help establish the pattern of symptoms and identify whether other vestibular conditions such as BPPV, vestibular hypofunction, Vestibular Migraine or visual motion sensitivity are contributing.
Assessment may include:
- Detailed history of the onset and precipitating event
- Oculomotor examination
- Bedside Head Impulse Testing
- Positional testing for BPPV
- Assessment of pressure- or sound-provoked symptoms where clinically appropriate
- Balance assessment
- Gait assessment
- Motion sensitivity assessment
Where the presentation raises concern regarding PLF, further investigation through an ENT or Neuro-Otologist may be appropriate.
This may include:
- Comprehensive audiometry
- Vestibular function testing
- VEMP testing
- High-resolution CT of the temporal bones
- MRI where indicated
- Specialist assessment for intratympanic blood patch or surgical exploration in selected cases
For patients with an established and medically stable PLF, or following surgical repair, Vestibular Physiotherapy can then address residual balance impairment, vestibular hypofunction, gaze instability, motion sensitivity and return to normal activities.
The most important point is that Perilymphatic Fistula is not diagnosed from one symptom or one bedside test.
A patient who becomes dizzy when coughing does not automatically have a PLF.
Similarly, a negative fistula test or normal scan does not necessarily exclude a small fistula.
The diagnosis requires careful consideration of:
How the symptoms started + hearing symptoms + vestibular symptoms + pressure sensitivity + clinical examination + audiological/vestibular testing + imaging where appropriate.
When those pieces are considered together, clinicians can determine whether a Perilymphatic Fistula is a reasonable explanation and what the safest next step should be.
The Vertigo Co – Melbourne Vestibular Physiotherapy
If you are experiencing persistent dizziness or balance problems following head trauma, barotrauma, diving, air travel or another pressure-related event, particularly when accompanied by hearing changes or pressure-induced dizziness, consider a comprehensive Vestibular Physiotherapy assessment.
This article provides general educational information only and is not a substitute for individual medical assessment. Perilymphatic Fistula can be difficult to diagnose, and the diagnostic approach remains an area of ongoing clinical debate. Sudden hearing loss, severe acute vertigo following trauma or barotrauma, or new neurological symptoms require prompt medical assessment.
