Labyrinthitis is an inflammation of the inner ear that is often a complication of infection of the middle ear ( otitis media ). It is usually caused by the spread of bacterial or viral infections from the head or respiratory tract into the inner ear.
The labyrinth is a group of interconnected canals chambers located in the inner ear. It is made up of the cochlea and the semicircular canals. The cochlea is involved in transmitting sounds to the brain. The semicircular canals send information to the brain about the head's position and how it is moving. The brain uses this information to maintain balance. Labyrinthitis is caused by the inflammation of the labyrinth. Its most frequent symptom is vertigo ( dizziness ), because the information that the semicircular canals send to the brain about the position of the head is affected.
Labyrinthitis is rare and is more likely to occur after middle ear infections, meningitis , or upper respiratory infection. It may also occur after trauma, because of a tumor, or after the ingesting of toxic substances. It is thought to be more common in females than in males.
Causes and symptoms
When a disease agent causes labyrinthitis, the disease agent usually reaches the inner ear by one of three routes:
- Bacteria may be carried from the middle ear or the membranes that cover the brain.
- Viruses, such as those that cause mumps , measles , influenza , and colds may reach the inner ear following an upper respiratory infection.
- The rubella virus can cause labyrinthitis in infants prior to birth.
Labyrinthitis can also be caused by toxins, by a tumor in the ear, by trauma to the ear, and sometimes high doses of medications or allergies .
The primary symptoms of labyrinthitis are vertigo and hearing loss, along with a sensation of ringing in the ears called tinnitus. Vertigo occurs because the inner ear controls the sense of balance, as well as hearing. Some individuals also experience nausea and vomiting and spontaneous eye movements in the direction of the unaffected ear. Bacterial labyrinthitis may produce a discharge from the infected ear.
When to call the doctor
If a child has vertigo, especially along with nausea , vomiting , or hearing loss, the doctor should be called.
Diagnosis of labyrinthitis is based on a combination of the individual's symptoms and history, especially a history of a recent upper respiratory infection. The doctor will test the child's hearing and order a laboratory culture to identify the organism if the patient has a discharge.
If there is no history of a recent infection, the doctor will order tests such as a commuted topography (CT) scan or a magnetic resonance imaging (MRI) scan to help rule out other possible causes of vertigo, such as tumors. If it is believed a bacterium is causing the labyrinthitis, blood tests may be done, or any fluid draining from the ear may be analyzed to help determine what type of bacteria is present.
If a bacterial agent is found to be the cause, the individual is given antibiotics to clear up the infection. Antibiotics cannot cure viral infections. Some patients may require surgery to drain the inner and middle ear. If an underlying condition such as a tumor is found to be the cause of the labyrinthitis, treatment will depend on the underlying condition.
Because most labyrinthitis resolves on its own, most treatment is focused on controlling the symptoms. Medications may be prescribed to help reduce vertigo and nausea. If vomiting cannot be controlled, so that fluids cannot be kept down, fluids may be administered intravenously to prevent dehydration .
Individuals with labyrinthitis should rest in bed until the acute dizziness subsides. Some experts believe that recovery is aided by moving around once the most acute symptoms are no longer present. This can be difficult, however, because moving often makes symptoms worse.
Most people who have labyrinthitis recover completely, although it often takes five to six weeks for the vertigo to disappear entirely and the individual's hearing to return to normal. In a few cases, the hearing loss may be permanent. Permanent hearing loss is more common in cases of labyrinthitis that are caused by bacteria. For some individuals, episodes of dizziness may still occur months after the main episode is over.
The most effective preventive strategy includes prompt treatment of middle ear infections, as well as monitoring of patients with mumps, measles, influenza, or colds for signs of dizziness or hearing problems.
Labyrinthitis generally resolves by itself; however, in some cases permanent hearing loss can result. Labyrinthitis may cause repeated episodes of vertigo even after the main symptoms have gone away. If the episodes occur when the head is moved suddenly, this can make it difficult for a child to engage in some physical activities or sports .
Labyrinth —The bony cavity of the inner ear.
Otitis media —Inflammation or infection of the middle ear space behind the eardrum. It commonly occurs in early childhood and is characterized by ear pain, fever, and hearing problems.
Vertigo —A feeling of dizziness together with a sensation of movement and a feeling of rotating in space.
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American Academy of Pediatrics. 141 Northwest Point Boulevard, Elk Grove Village, IL 60007–1098. Web site: http://www.aap.org.