Labyrinthitis is an inflammation of the inner ear. The labyrinth is a structure of fluid-filled sacs and tubes just inside the skull. It contains two important organs: the cochlea, which is necessary for hearing, and the balance organs (vestibular system), which tell people which way is up and down, even when their eyes are shut. Either one or both of these organs can be affected. The entire labyrinth is less than a half inch (1.25 cm) across, so infection can easily spread throughout.
The inner ear also contains a bundle of nerves leading from these organs to the brain. Inflammation of these nerves is called vestibular neuronitis (or vestibular neuritis). It's sometimes difficult to find out whether it is the labyrinth or the nerves that are inflamed.
The exact cause of labyrinthitis is often unknown. It may be related to a viral infection such as the flu or a cold or, rarely, a bacterial infection such as a middle ear infection (otitis media) or meningitis. Bacterial labyrinthitis may occur in people who have an injury called a perilymph fistula (a hole between the middle and inner ears through which bacteria can enter). This type of injury is often caused by sudden changes in pressure as in explosions, diving, and skydiving.
Labyrinthitis may rarely occur as part of an autoimmune disease or after a head or ear injury. Other more rare causes can include allergies, medications that can damage the inner ear, drinking large amounts of alcohol, stress, a stroke, or a tumour.
Symptoms and Complications
The main symptoms of labyrinthitis are vertigo (a spinning sensation) and hearing loss. If a person has vertigo, they feel as if they are spinning or as if things are spinning around them.
Symptoms may be mild, with slight vertigo and mild tinnitus (ringing or buzzing in the ears). On the other hand, more severe cases may lead to a rare sudden loss of hearing in the affected ear. Severe vertigo with these severe symptoms may lead to nausea and possibly vomiting, as well as difficulty focusing your vision. Loss of balance may also occur.
Often, the inflammation goes away on its own within a couple of weeks, and both hearing and balance return to normal. However, labyrinthitis may cause long-term or permanent damage. If it affects the vestibular system, it can damage a person's sense of balance for several years after the inflammation is gone. If it affects the cochlea, it may cause hearing damage.
Making the Diagnosis
There's no easy test for labyrinthitis, as the inner ear is difficult to reach. Your doctor will ask you questions about your symptoms and perform a physical exam, paying special attention to your ears, eyes, and nerve function. If the main symptom you have is dizziness or vertigo, your doctor will want to eliminate other possible causes such as migraine, stroke, medications, and neurologic disease.
Tests sometimes used to find the cause of the dizziness or vertigo include hearing tests, balance tests (electronystagmography or posturography), computed tomography (CT) scan, magnetic resonance imaging (MRI) scan, eye tests, caloric stimulation (placing cold water and then warm water in the ear canal to test the function of the inner ear nerve), or tests to look at brain function (electroencephalogram or EEG).
Treatment and Prevention
There is no treatment for viral labyrinthitis and there's not much anyone can do to prevent it. People with viral labyrinthitis must wait for the inflammation to go away on its own. For most people the symptoms will generally start to improve after 1 to 3 weeks, with full recovery within 1 or 2 months. Bacterial labyrinthitis, which is rare, can be treated with antibiotics.
To help you cope with the symptoms, your doctor may prescribe medications for nausea and vertigo. Corticosteroids may also be prescribed to reduce inflammation within the inner ear.
It can also help to stay still, rest, and avoid bright lights, reading, and moving suddenly.
Ease back into your regular activities once your symptoms are gone. Wait until you've been symptom-free for about a week before driving or doing other hazardous activities.