Perilymph fistula
Encyclopedia
A labyrinthine fistula is an abnormal opening in the bony capsule of the inner ear
, resulting in leakage of the perilymph from the semicircular canals 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
. This connection is caused by a rupture of the oval window
or round window
that separate the inner and middle ear . Another type of l.f. is a semicircular canal dehiscence, which allows the inner ear to be influenced by the intracranial pressure directly.
These can be both congenital or develop over time with the thinning of the otic capsule by the persistent pulsations of the intracranial pressures against the bones of the skull. Finally, disease conditions—for example cholesteatoma
—can result in a labyrinthine fistula.. Traumatic events, with excessive pressure changes to the inner ear such as in deep-water diving, head trauma, or an extremely loud noise can lead to rupture and leakage .
PLF is a cause of dizziness
, imbalance
, and hearing loss—any or all of these symptoms can exist. Vertigo
(an illusion of motion) is not common in this disorder. The most common cause of this fistula is head or ear trauma. Rapid increases of intracranial pressure can also result in a PLF. Rarely, these fistulas can be congenital, leading to progressive hearing loss and vertigo in childhood. It has also been a complication of a stapedectomy
.
Unlike other vestibular systems that are treated well with physical therapy (BPPV), it is a contraindication for most patients with PLF. Patients are advised to treat with bed rest with the hopes of the membrane healing on their own .
When diagnosing, PLF should be differentiated from Ménière's disease
. Tympanostomy has been reported to be a way to diagnose and cure PLF.
Inner ear
The inner ear is the innermost part of the vertebrate ear. In mammals, it consists of the bony labyrinth, a hollow cavity in the temporal bone of the skull with a system of passages comprising two main functional parts:...
, resulting in leakage of the perilymph from the semicircular canals 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
Middle ear
The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the cochlea. The mammalian middle ear contains three ossicles, which couple vibration of the eardrum into waves in the fluid and membranes of the inner ear. The hollow space of the middle ear has...
. This connection is caused by a rupture of the oval window
Oval window
The oval window is a membrane-covered opening which leads from the middle ear to the vestibule of the inner ear.Vibrations that come into contact with the tympanic membrane travel through the three ossicles and into the inner ear...
or round window
Round window
The round window is one of the two openings into the inner ear. It is closed off from the middle ear by the round window membrane, which vibrates with opposite phase to vibrations entering the inner ear through the oval window...
that separate the inner and middle ear . Another type of l.f. is a semicircular canal dehiscence, which allows the inner ear to be influenced by the intracranial pressure directly.
These can be both congenital or develop over time with the thinning of the otic capsule by the persistent pulsations of the intracranial pressures against the bones of the skull. Finally, disease conditions—for example cholesteatoma
Cholesteatoma
Cholesteatoma is a destructive and expanding growth consisting of keratinizing squamous epithelium in the middle ear and/or mastoid process.-Signs and symptoms:...
—can result in a labyrinthine fistula.. Traumatic events, with excessive pressure changes to the inner ear such as in deep-water diving, head trauma, or an extremely loud noise can lead to rupture and leakage .
PLF is a cause of dizziness
Dizziness
Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
, imbalance
Balance disorder
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...
, and hearing loss—any or all of these symptoms can exist. Vertigo
Vertigo
Vertigo is a form of dizziness.Vertigo may also refer to:* Vertigo , a 1958 film by Alfred Hitchcock**Vertigo , its soundtrack** Vertigo effect, or Dolly zoom, a special effect in film, named after the movie...
(an illusion of motion) is not common in this disorder. The most common cause of this fistula is head or ear trauma. Rapid increases of intracranial pressure can also result in a PLF. Rarely, these fistulas can be congenital, leading to progressive hearing loss and vertigo in childhood. It has also been a complication of a stapedectomy
Stapedectomy
A stapedectomy is a surgical procedure of the middle ear performed to improve hearing. The world's first stapedectomy is credited to Dr. John J.Shea Jr. who performed it in May 1956 on a 54-year-old housewife who could no longer hear even with a hearing aid. Significant contributions to modern...
.
Unlike other vestibular systems that are treated well with physical therapy (BPPV), it is a contraindication for most patients with PLF. Patients are advised to treat with bed rest with the hopes of the membrane healing on their own .
When diagnosing, PLF should be differentiated from Ménière's disease
Ménière's disease
Ménière's disease is a disorder of the inner ear that can affect hearing and balance to a varying degree. It is characterized by episodes of vertigo and tinnitus and progressive hearing loss, usually in one ear. It is named after the French physician Prosper Ménière, who, in an article published...
. Tympanostomy has been reported to be a way to diagnose and cure PLF.
External links
- http://www.dizziness-and-balance.com/disorders/unilat/fistula.html