A labyrinthine fistula is an abnormal opening in the

inner ear The inner ear (internal ear, auris interna) is the innermost part of the vertebrate ear. In vertebrates, the inner ear is mainly responsible for sound detection and balance. In mammals, it consists of the bony labyrinth, a hollow cavity in the ...

. This can result in leakage of the

perilymph Perilymph is an extracellular fluid located within the inner ear. It is found within the scala tympani and scala vestibuli of the cochlea. The ionic composition of perilymph is comparable to that of plasma and cerebrospinal fluid. The major ca ...

into the middle ear. This includes specifically a perilymph fistula (PLF), an abnormal connection between the fluid of the inner ear and the air-filled

middle ear The middle ear is the portion of the ear medial to the eardrum, and distal to the oval window of the cochlea (of the inner ear). The mammalian middle ear contains three ossicles, which transfer the vibrations of the eardrum into waves in the ...

. This is caused by a rupture of the

round window The round window is one of the two openings from the middle ear into the inner ear. It is sealed by the secondary tympanic membrane (round window membrane), which vibrates with opposite phase to vibrations entering the inner ear through the oval w ...

oval window The oval window (or ''fenestra vestibuli'' or ''fenestra ovalis'') is a membrane-covered opening from the middle ear to the cochlea of the inner ear. Vibrations that contact the tympanic membrane travel through the three ossicles and into the in ...

ligaments separating the inner and middle ear. Another type of labyrinthine fistula is the superior semicircular canal dehiscence, which allows the inner ear to be influenced by the

intracranial The cranial cavity, also known as intracranial space, is the space within the skull that accommodates the brain. The skull minus the mandible is called the ''cranium''. The cavity is formed by eight cranial bones known as the neurocranium that in ...

pressure directly.

Signs and symptoms

PLF usually induces one or all the following pathological states: aural fullness, fluctuating or non-fluctuating

hearing loss Hearing loss is a partial or total inability to Hearing, hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to Language ...

tinnitus Tinnitus is the perception of sound when no corresponding external sound is present. Nearly everyone experiences a faint "normal tinnitus" in a completely quiet room; but it is of concern only if it is bothersome, interferes with normal hearin ...

and

dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a common medical c ...

, which may sometimes include

vertigo Vertigo is a condition where a person has the sensation of movement or of surrounding objects moving when they are not. Often it feels like a spinning or swaying movement. This may be associated with nausea, vomiting, sweating, or difficulties w ...

and

balance disorders A balance disorder is a disturbance that causes an individual to feel unsteady, for example when standing or walking. It may be accompanied by feelings of giddiness, or wooziness, or having a sensation of movement, spinning, or floating. Balance ...

Cause

Labyrinthine fistula can be both

congenital A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...

or develop over time with the thinning of the

otic capsule The bony labyrinth (also osseous labyrinth or otic capsule) is the rigid, bony outer wall of the inner ear in the temporal bone. It consists of three parts: the vestibule, semicircular canals, and cochlea. These are cavities hollowed out of the s ...

by the persistent pulsations of the intracranial pressures against the bones of the skull. Finally, disease conditions—for example

cholesteatoma Cholesteatoma is a destructive and expanding growth consisting of keratinizing squamous epithelium in the middle ear and/or mastoid process. Cholesteatomas are not cancerous as the name may suggest, but can cause significant problems because of the ...

—can result in a labyrinthine fistula. Traumatic events, with excessive pressure changes to the inner ear such as in

scuba diving Scuba diving is a mode of underwater diving whereby divers use breathing equipment that is completely independent of a surface air supply. The name "scuba", an acronym for "Self-Contained Underwater Breathing Apparatus", was coined by Chris ...

, head trauma, or an extremely loud noise can lead to rupture and leakage. The most common causes of PLF are: head or ear traumas, rapid increases of intracranial pressure,

abnormalities (in children), complication of

stapedectomy A stapedectomy is a surgical procedure of the middle ear performed in order to improve hearing. If the stapes footplate is fixed in position, rather than being normally mobile, the result is a conductive hearing loss. There are two major causes of ...

, barotraumas (e.g. slap/suction, scuba diving, skydiving, strong and repetitive nose-blowing or sneezing, heavy lifting).

Diagnosis

When diagnosing, PLF should be differentiated from

Ménière's disease Ménière's disease (MD) is a disease of the inner ear that is characterized by potentially severe and incapacitating episodes of vertigo, tinnitus, hearing loss, and a feeling of fullness in the ear. Typically, only one ear is affected initial ...

. Tympanostomy has been reported to be a way to diagnose and cure PLF.

Treatment

Patients are advised to treat with bed rest and avoiding activities that increase intracranial pressure (i.e. weightlifting, Valsalva maneuver, scuba diving, flying in airplanes) with the hopes of the membrane healing on its own. Appropriate Physical therapy / vestibular rehabilitation techniques can be helpful in managing symptoms of movement sensitivity.

References

External links

* http://www.dizziness-and-balance.com/disorders/unilat/fistula.html {{Hearing and balance Diseases of inner ear