Perilymph Fistula in Emergency Medicine 

Updated: Mar 10, 2016
Author: Nancy E Conroy, MD; Chief Editor: Steven C Dronen, MD, FAAEM 

Overview

Background

A perilymph fistula (perilymphatic fistula [PLF], labyrinthine fistula) is a pathologic communication between the fluid-filled space of the inner ear and the air-filled space of the middle ear, most commonly occurring at either the round or oval window.[1] The primary manifestations of perilymph fistulization are sudden or progressive fluctuating sensorineural hearing loss and vertigo. Other symptoms that may be present include tinnitus, disequilibrium, and aural fullness.

This clinical entity was proposed more than a century ago, yet it remains a topic of controversy, especially regarding the occurrence of spontaneous perilymph fistula (PLF). Trauma and poststapedectomy are etiologies proven to cause PLFs and must be considered in the appropriate settings. A PLF should be considered in pediatric patients with recurrent meningitis, and the option of middle ear exploration should be pursued. It is likely that most pediatric patients with PLFs will have an anatomic abnormality of their middle ear or labyrinth. It is also known that although several potential pathways exist between the perilymphatic space and the middle ear, actual leaking of fluid can be difficult or impossible to prove.

There is no agreed upon diagnostic test with enough sensitivity and specificity to identify the presence or absence of perilymph fistula. This has made it difficult to establish criteria to determine when surgical exploration might be indicated. Additionally, there are no universally accepted criteria to confirm diagnosis at surgery; the determination of the presence or absence of PLF is the subjective decision of the surgeon. Additionally, the presence of clear fluid in the middle ear at the time of surgery may represent perilymph or may be CSF, serum, or local anesthetic. No reliable and accurate test is currently available to reliably distinguish these fluids from one another. No studies have been reported to account for the substantial placebo effect of a surgical procedure for vertiginous symptoms in patients with suspected PLF, and no appropriate long-term follow up of patients after surgery has been reported.

The presenting complaint and symptoms of perilymph fistula are often consistent with Meniere syndrome. Therefore, in the absence of prior surgery or definite traumatic event, distinguishing a perilymph fistula from Meniere syndrome may be difficult.

Pathophysiology

Most commonly, a tear in the round or oval window leads to loss of perilymph into the middle ear. This condition may be the result of stapes prosthesis surgery, trauma, barotrauma, or bony erosion due to infection or neoplasm, or it may be idiopathic. Markou et al reported on a patient who developed a perilymph fistula in the round window due to a whiplash injury.[2] In children, perilymph fistulas are associated with congenital anomalies of the middle or inner ear.

Epidemiology

Mortality/Morbidity

In children, the condition may be associated with recurrent meningitis. Acute or chronic perilymph fistulas may significantly affect quality of life.

Sex

Prevalence of perilymph fistula is higher in females than in males.

Age

Perilymph fistulas occur in young children with congenital abnormalities; otherwise, the condition is not known to be age specific.

 

Presentation

History

History for perilymph fistula may include the following:

  • Fluctuating sensorineural hearing loss that may be sudden or progressive

  • Vestibular symptoms

    • Vertigo, with or without head position changes

    • Dysequilibrium

    • Motion intolerance

    • Nausea and vomiting

    • Disorganization of memory and concentration

    • Perceptual disorganization in complex surroundings such as crowds or traffic

  • Tinnitus - May be roaring in nature

  • Aural fullness

A retrospective study by Haubner et al of 69 patients who suffered unilateral sudden deafness (from sensorineural hearing loss) found that just a minority of these patients had a perilymph fistula. In the study, in which the patients underwent exploratory myringotomy, 18.8% of patients had a visible perilymph fistula, while possible, but doubtful, perilymph fistula was diagnosed in another 21.7%; no signs of fistulae were found in 59.4% of patients. Moreover, the investigators found themselves unable to predict the presence of a perilymph fistula, stating that intraoperative findings were not correlated to the patient’s history or the preoperative diagnosis of tinnitus or vertigo. (A typical history for a round window membrane rupture was not reported by 89.8% of the study’s patients.)[3]

Physical

See the list below:

  • Positive test results for vestibular dysfunction or hearing loss, while helpful, are not pathognomonic.

  • Romberg (feet together) or tandem Romberg (heel-to-toe) test findings may be positive.

  • Positional nystagmus and benign paroxysmal positional vertigo often are associated with traumatic perilymph fistula.

  • Sensorineural hearing loss may be confirmed by audiograms.

Causes

See the list below:

  • Prior stapes surgery

  • Head trauma, including whiplash injuries

  • Barotrauma

  • Acoustic trauma

  • Idiopathic or spontaneous, possibly related to episodes of valsalvae, nose blowing, or physical exertion (The existence of spontaneous perilymph fistula is still an area of controversy among otologists.)

 

DDx

Diagnostic Considerations

These include the following:

  • Vertebrobasilar dissection

  • Cerebellar stroke

  • Autoimmune etiology

  • Hereditary hearing loss

  • Vascular disease

Differential Diagnoses

 

Workup

Imaging Studies

See the list below:

  • No diagnostic test can be considered a criterion standard for perilymph fistula, and none are immediately useful in the emergency department.

  • Clinical history and symptoms are more sensitive than radiographic studies for the assessment of perilymph fistula.

  • A CT scan or MRI may be indicated with a history of head trauma if temporal bone fracture is considered, but their use as diagnostic studies for nontraumatic perilymph fistulas is questionable.

    • High-resolution CT scans are inadequate for evaluation of the round and oval window regions.

    • MRI with intrathecal gadolinium enhancement can detect inner and middle ear communication, but a more cost-effective modality is preferred.

Other Tests

See the list below:

  • Otologists may use the following tests to diagnose perilymph fistulas:

    • Audiograms to detect hearing loss

    • Electrocochleography

    • Fistula tests (Hennebert sign): The subjective fistula test is performed by applying positive and negative pressure to the intact eardrum using a pneumatic otoscope. Positive results include the elicitation of nystagmus or onset of dysequilibrium with the sensation of motion or nausea. Some otologists administer the test with electronystagmography or by using platform posturography.

  • Perilymph labeling methods

    • Initial studies used intrathecal or intravenous fluorescein, but these have been abandoned for perilymph-specific protein testing, such as beta-2 transferrin, apo D, and apo J.

    • Beta-2 transferrin, a protein found in perilymph and CSF but not in serum, has been the most actively studied. Initial enthusiasm for a Western blot assay for this protein has wavered due to low sensitivity. The presence of beta-2 transferrin in perilymph has been unreliable, possibly due to current collection methods or small sample volumes, and false-positive results may be secondary to CSF contamination during collection.

    • Focus has recently switched to the efficacy of apolipoprotein D (apo D) as a marker for perilymph with encouraging results.

    • Results of a study by Ikezono et al strongly suggest that cochlin-tomoprotein may be a specific marker of perilymph leakage. Additionally, cochlin-tomoprotein could be a potential marker, allowing definitive diagnosis of perilymph fistula related hearing loss and vestibular disorders.[4, 5]

Procedures

See the list below:

  • The current criterion standard for confirmation of perilymph fistula is direct visualization either by operative middle ear exploration or by in-office endoscopy.

  • The subjectivity of this diagnostic maneuver has been questioned because no universally accepted criteria exist for diagnosis during surgery. More objective tests are being developed, particularly those that identify compounds specific to perilymph upon the examination of the fluid contents.

 

Treatment

Emergency Department Care

The primary purpose of emergency evaluation is to seek other, more emergent causes of symptoms. However, consider the diagnosis with hearing loss and vertigo following head trauma. Vertigo suppressants, such as diazepam and meclizine, may be used, although their benefit remains unproven in this setting. Medical therapy is rarely reported. Some reports exist of spontaneous healing with bedrest, head elevation to 30°, and avoidance of lifting or middle-ear pressure–increasing activities.

Consultations

Consult with an otolaryngologist.

 

Follow-up

Further Outpatient Care

See the list below:

  • Strict bedrest for 5-7 days or until reevaluation

  • Elevation of the patient's head above the heart level

  • Avoidance of straining

  • Avoidance of nose blowing or Valsalva maneuver

  • No lifting (>10 lb)

  • Stool softeners

Further Inpatient Care

See the list below:

  • Bedrest with the head of the bed elevated to 30°

  • Avoidance of lifting or pressure-increasing activities (ie, Valsalva maneuver)

  • Surgical intervention is the principle approach to treatment when perilymph fistula is diagnosed. The site of perilymph leak is covered with some form of autologous tissue.

Complications

See the list below:

  • Both the patient and the physician should be prepared for no response to treatment, especially with regard to hearing improvement. Recurrence of postoperative signs and symptoms may occur in 21-47% of patients.

  • Perilymph fistula may be associated with recurrent meningitis in children.

Prognosis

See the list below:

  • Because of the difficulty in making the diagnosis of perilymph fistula, the natural history of this disorder is unknown.

  • Significant improvement in symptoms that are presumed to be from perilymph fistula may occur with conservative treatment.

  • Surgery is more successful in relieving vertiginous symptoms than in improving hearing.