Labyrinthine fistula

Labyrinthine fistula is a pathological condition characterized by an abnormal opening in the bony capsule of the inner ear, leading to the leakage of perilymph (the fluid within the inner ear) into the middle ear (a condition known as perilymph fistula). This condition can result in hearing loss, vertigo, and tinnitus. Labyrinthine fistulas are most commonly caused by chronic otitis media, a long-standing infection of the middle ear, but can also result from head trauma, cholesteatoma (a type of skin cyst in the middle ear), or otologic surgery.

Causes

The primary causes of labyrinthine fistula include:

• Chronic Otitis Media: Persistent infection of the middle ear can erode the bony structures, including the otic capsule, leading to fistula formation.
• Cholesteatoma: A benign growth that can erode the bone of the inner ear, creating a fistula.
• Head Trauma: Severe head injuries can fracture the temporal bone, causing an immediate or delayed fistula.
• Otologic Surgery: Surgical procedures on the ear, especially those involving the removal of cholesteatomas or other masses, can inadvertently create a fistula.

Symptoms

Patients with labyrinthine fistula may experience a variety of symptoms, including:

• Hearing Loss: Conductive, sensorineural, or mixed hearing loss can occur, depending on the extent of the damage.
• Vertigo: Spinning sensation, which may be triggered or worsened by changes in pressure within the ear (such as during sneezing, coughing, or straining).
• Tinnitus: Ringing or buzzing in the affected ear.
• Nystagmus: Involuntary eye movement, which may accompany vertigo.

Diagnosis

Diagnosis of labyrinthine fistula involves a combination of clinical history, physical examination, and specialized tests:

• Audiometry: To assess the type and degree of hearing loss.
• Tympanometry: To evaluate the condition of the middle ear and its pressure.
• Computed Tomography (CT) Scan: High-resolution CT scans can help visualize the bony defect of the fistula.
• Magnetic Resonance Imaging (MRI): To differentiate between a fistula and other inner ear conditions.

Treatment

Treatment options for labyrinthine fistula depend on the severity of symptoms and the underlying cause:

• Conservative Management: In cases of mild symptoms, observation and avoidance of activities that increase inner ear pressure may be recommended.
• Surgical Repair: For symptomatic fistulas, surgery to close the fistula and reconstruct the bony capsule is often necessary.
• Antibiotics: If an infection is present, antibiotics may be prescribed to control it.
• Vestibular Rehabilitation: Therapy to help manage vertigo and improve balance.

Prognosis

The prognosis for individuals with labyrinthine fistula varies. Surgical repair can often improve or stabilize hearing loss and alleviate vertigo. However, the risk of recurrent fistula or persistent symptoms exists, especially if the underlying cause is not fully addressed.

See Also

• Inner Ear
• Middle Ear
• Perilymph Fistula
• Otitis Media
• Cholesteatoma