Labyrinthitis

Labyrinthitis is a disorder arising from bacterial or viral infection in the labyrinth – a complex system of membranes and bones that is located in the inner ear.

Labyrinthitis concerns the vestibulocochlear nerve, a system of neural connections that links the inner ear to the brain and central nervous system and is responsible for balance as well as hearing. When the labyrinth is hit by an infection, the resulting condition can cause disturbances in balance and hearing and can set off dizziness and vertigo, among other symptoms.

Another common side effect of labyrinthitis chronic anxiety, which can produce tremors, heart palpitations, panic attacks, derealization and depression. Often, a panic attack is one of the first symptoms to occur as labyrinthitis begins.

Viral labyrinthitis

Viral labyrinthitis is characterized by an immediate loss of vestibular function and hearing. Symptoms of this disorder are nausea and vomiting and can temporarily incapacitate the patient, causing him or her to be bedridden.

After several days or weeks, vertigo eventually wears off; however, unsteadiness may persist for several months. If symptoms of dizziness or imbalance persist for several months, vestibular rehabilitation exercises (physical therapy) may be suggested in order to retrain the brain’s ability to adjust to the vestibular imbalance. A key component of successful adaptation is a dedicated effort to keep moving, despite the symptoms of dizziness and imbalance. A key symptom in many patients afflicted with viral labyrinthitis is hearing loss.

Viral labyrinthitis is often confused with vestibular neuritis, a disorder of the vestibular nerve and not associated with hearing loss. The condition is more common in patients aged 40 to 60 and affects men and women equally. An upper respiratory tract infection often precedes the condition.

Viral infections can cause both congenital and acquired hearing loss. Rubella- and cytomegalovirus-induced infections are the best-recognized causes of hearing loss in children who had suffered the condition prior to birth. Virally induced hearing loss during the postnatal period is usually due to mumps or measles.

Bacterial labyrinthitis

Bacterial labyrinthitis is not as prevalent as it was before prior to the emergence of more antibiotics. Bacterial labyrinthitis is a consequence of meningitis or otitis media and may occur by either direct bacterial invasion or through the entry of bacterial toxins and other inflammatory mediators into the inner ear. Meningitis is typically bilateral, or affects both ears, whereas otogenic infections typically cause unilateral symptoms. Bacteria can spread from the cerebrospinal fluid to the membranous labyrinth by way of the internal auditory canal or cochlear aqueduct.

Treatment of this disorder is aimed at eradicating the underlying infection, providing supportive care to the patient, draining middle ear effusions or mastoid infections, and preventing the spread of infection.

Autoimmune labyrinthitis is an uncommon cause of sensorineural hearing loss and may occur as a local, inner ear process or as part of a systemic autoimmune disease such as Wegener granulomatosis or polyarteritis nodosa. Hearing loss in autoimmune inner ear disease is typically bilateral and progressive over weeks to months, and vestibular complaints may occur in up to eight out of ten patients with autoimmune inner ear disease.

Prevalence

Viral labyrinthitis is the most common form of labyrinthitis. In the United States, the prevalence of sudden sensorineural hearing loss (SNHL) – a condition directly attributed to labyrinthitis – is estimated at one case in 10,000 persons. In an era where access to antibiotics is not a major concern, bacterial labyrinthitis cases are rare, although bacterial meningitis, a related condition, remains a significant cause of hearing loss. Auditory symptoms, vestibular symptoms or both may be present in as many as 20 percent of children with meningitis.

There have been no deaths associated with labyrinthitis except in cases when the condition has deteriorated to meningitis or overwhelming sepsis.

Viral labyrinthitis is usually observed in adults aged 30 to 60 and is rarely observed in children.