The labyrinth is the inner ear consisting of the vestibule, cochlear and semicircular canals. The cochlea is concerned with hearing and the vestibule and semicircular canals with equilibrium (sense of balance). The bony portion of the labyrinth (osseous labyrinth) is composed of a series of canals tunneled out of the temporal bone. Labyrinthitis is an infection of the labyrinth, the fluid-filled chamber of the inner ear that controls balance and hearing. It is almost always caused by viral infection, but can rarely be caused by bacteria. The viral form may occur during a flu-like illness or during illnesses such as measles or mumps. Bacterial labyrinthitis can result from inadequately treated or sub-acute otitis media (infection of the middle ear). Infection may also reach the inner ear via the bloodstream from elsewhere in the body. Less commonly, bacterial labyrinthitis results from a head injury.
The main symptom of labyrinthitis is vertigo. Vertigo is not the same as feeling dizzy. Dizziness means you feel unsteady or lightheaded. Vertigo is an abnormal sensation of movement. It makes you feel like you’re spinning or whirling. Symptoms of vertigo and dizziness may be caused by many problems other than labyrinthitis. With this disorder, the vertigo begins without warning. It often starts 1 to 2 weeks after you’ve had the flu or a cold. It may be severe enough to make you vomit or make you feel sick to your stomach. Vertigo slowly goes away over a few days to weeks. But for a month or longer you may still get vertigo symptoms if you suddenly move your head a certain way. You might also experience difficulty focusing the eyes because of involuntary eye movements. Labyrinthitis may also cause hearing loss and a ringing sound in your ears (tinnitus). Most often, these symptoms don’t last for more than a few weeks. The risk for this disorder may be raised by drinking large amounts of alcohol, fatigue, a history of allergies, a recent viral illness, a recent respiratory or ear infection, smoking and stress.
Labyrinthitis usually goes away within a few weeks. However, symptoms may need treatment. Your doctor may prescribe an antibiotic to treat the infection. Medications that may reduce symptoms include antihistamines, corticosteroids such as prednisone when symptoms are severe, medicines such as compazine to control nausea and vomiting, medicines to relieve dizziness such as meclizine or scopalamine and sedative-hypnotics such as Valium. To prevent worsening of symptoms during episodes of labyrinthitis, it is suggested that you keep still and rest when symptoms occur, gradually resume activity, avoid sudden position changes, do not try to read when symptoms occur and avoid bright lights. In addition, you might need help walking when symptoms occur and it is extremely important to avoid hazardous activities such as driving, operating heavy machinery and climbing until 1 week after symptoms have disappeared.
Call your health care provider if dizziness, vertigo, loss of balance, or other symptoms of labyrinthitis are present. Also call if hearing loss occurs. Urgent or emergency symptoms include double vision, weakness or paralysis, slurring of speech, convulsions, fainting, persistent vomiting or vertigo accompanied by fever of more than 101 degrees Fahrenheit. If you have severe vomiting with some of the symptoms listed, you may be admitted to the hospital. A complete physical and neurological exam will be done, because an ear examination may not reveal any problems. Usually, the diagnosis of labyrinthitis does not require other tests. However, tests will be done to rule out other causes for your symptoms. These may include EEG, Electronystagmography, evoked auditory potential studies, head CT scan, hearing tests (audiology/audiometry), MRI of the head and warming and cooling the inner ear with water (caloric stimulation) to test eye reflexes. Severe symptoms usually go away within a week. Most patients are completely better within 2 to 3 months. Continued dizziness is more likely to last in older patients. Hearing usually returns to normal.