What is the labyrinth and what does it do?
The labyrinth is in the inner ear. The inner ear includes the cochlea, vestibule and and semicircular canals. These are small 'shell-like' structures in which there is a system of narrow fluid-filled channels called the labyrinth. The semicircular canals sense movement of your head and help to control balance and posture. The cochlea is concerned with hearing.
There are three semicircular canals (anterior, lateral and posterior). These are roughly at right angles to each other and sense movement in different directions - left-right, forward-back, and up-down head movements. The semicircular canals are connected to a larger fluid filled chamber called the vestibule which in turn is connected to the fluid filled canal in the cochlea.
Head movements are sensed because when you move your head, the fluid in the labyrinth within the semicircular canals moves too. The movement of the fluid moves tiny fine hairs that are on the inside lining of the labyrinth. When the hairs move, this triggers nerve messages to be sent to the brain via a nerve called the vestibular nerve. This gives the brain information about the movement and position of your head, even when your eyes are closed.
Looking with your eyes, and nerve messages from the joints and muscles of the body also help to tell your brain about your position and posture. However, a properly working labyrinth in each ear is needed for a good sense of posture and balance.
What is labyrinthitis and vestibular neuritis?
- Labyrinthitis means inflammation of the labyrinth in the inner ear.
- Vestibular neuritis (sometimes called vestibular neuronitis) means inflammation of the vestibular nerve. This is the nerve that comes from the inner ear that takes messages from the semicircular canals to the brain.
The causes and symptoms of labyrinthitis and vestibular neuritis are similar. Often it is impossible to tell whether you have one or other or both of these conditions. (However, if hearing is affected in addition to other symptoms listed below, then labyrinthitis is more likely than vestibular neuritis. This is because the labyrinth in the cochlea may also be inflamed which can affect hearing.)
What are the causes of labyrinthitis and vestibular neuritis?
The common cause of labyrinthitis and vestibular neuritis is a viral infection. This is called viral labyrinthitis and viral vestibular neuritis. There are various viruses that can cause these problems. The infection may occur at the same time as, or just after, you have a common viral illness such as a sore throat, glandular fever, flu, or a cold. The cold sore virus may also be a cause. Sometimes you may not be aware of any other viral infection and just develop symptoms of labyrinthitis or vestibular neuritis.
Other causes are uncommon. Strictly speaking, 'itis' at the end of a word means inflammation. However, the terms labyrinthitis and vestibular neuritis are sometimes used for any damage or inflammation to the labyrinth or vestibular nerve, which can be due to various causes. For example, the following conditions will all have other symptoms and problems, but may also cause labyrinthitis or vestibular neuritis as a complication:
- Bacterial infection in the middle ear. Most ear infections do not spread into the inner ear but a labyrinthitis or vestibular neuritis are uncommon complications from a middle ear infection.
- Meningitis. The infection may spread from the brain to to the inner ear.
- Injury to the ear.
- An uncommon side effect of some drugs.
What are the symptoms of labyrinthitis and vestibular neuritis?
The main symptom is vertigo. Vertigo is dizziness with a spinning sensation. If you have vertigo you feel as if the world is spinning around you, and you feel very unsteady. Often you will also feel sick or vomit. Typically, if a viral infection is the cause (the common situation), you develop vertigo quite quickly.
The vertigo can become intense and constant for the first few days and you simply have to lie down until the symptoms ease. The vertigo may be less intense if you lie down, and is often made worse by sitting up, moving your head, or moving around. In milder cases the vertigo is less intense, but you feel unsteady when moving or walking around.
Vertigo occurs because the inflamed or damaged labyrinth or vestibular nerve sends conflicting signals to the brain compared to the normal ear. The brain becomes very confused about your head posture and 'reacts' to cause vertigo.
You may also have:
- Some mild hearing loss on the affected side if you have labyrinthitis.
- Nystagmus. This is a 'shaking' of the eyes from side to side or in a rotary movement. You might not notice this but a doctor will look for it as it is commonly present. (Labyrinthitis and vestibular neuritis are one cause of nystagmus. There are other causes.)
- Other symptoms of a virus infection such as a sore throat, flu symptoms or a cold.
- Pain in an ear. However, this is not normally a feature of a viral labyrinthitis or viral vestibular neuritis. If you have ear pain it may indicate that you have a bacterial middle ear infection that has spread to the inner ear.
Symptoms of a viral labyrinthitis or viral vestibular neuritis can last anything from a few days to several weeks. A typical case is for symptoms to be bad for 2-3 weeks, and then to gradually settle down over several days. There may be some slight unsteadiness for 2-3 months before symptoms clear completely. However, in a small number of cases, symptoms can persist for months or years. In these cases, the virus infection will have gone but the inflammation and damage caused by the infection may cause persisting symptoms.
Do I need any tests?
If you have a 'typical' episode of labyrinthitis or vestibular neuritis due to a viral infection then your doctor will usually be able to diagnose this on the basis of your symptoms and the examination. Tests are not usually needed or helpful.
However, you may be referred for tests such as a scan, hearing tests, balance tests, etc, if you have symptoms that suggest anything other than a viral infection, or if symptoms are not settling within 3-4 weeks.
What is the treatment for labyrinthitis and vestibular neuritis?
Treatment if a viral infection is the cause
No treatment will completely take away the symptoms - especially the main symptom of vertigo. You may simply have to accept that you will be dizzy, and may need to stay in bed until the viral infection runs it's course and the worst of the symptoms subside.
A doctor may prescribe anti-sickness medication if you are troubled with vomiting. Some drugs also help to quieten the nerve messages from the inner ear and may ease vertigo. For example, prochlorperazine. Occasionally, some people become so dehydrated due to the vomiting that goes with vertigo that they need to be admitted to hospital for a 'drip' until the vomiting stops.
Some doctors prescribe a short course of steroid tablets. The theory is that this may reduce the inflammation quicker than it would do naturally. It is not clear if this is of value.
If symptoms do not clear within a few weeks then you may be referred to an ear specialist who may recommend treatment called Vestibular Rehabilitation Therapy (VRT). This therapy uses physical and occupational therapy techniques to treat vertigo and balance disorders.
Treatment of other causes
Treatment of other less common causes depends on the cause. Your doctor will advise. For example, if you have a middle ear bacterial infection you may be prescribed antibiotics.
What is the prognosis (outcome)?
A bout of labyrinthitis or vestibular neuritis can make you feel very unwell, and put you to bed. However, in most cases, the cause is a viral infection and this usually clears away. Therefore, symptoms in most cases clear completely but this may take several weeks. Some cases are milder and you just feel a bit unsteady on your feet for a short time.
In a small number of cases, symptoms from a viral labyrinthitis or vestibular neuritis can persist for months or years. Also, there are more serious causes of labyrinthitis and vestibular neuritis, but are much less common. Therefore, tell your doctor if you do not improve, or develop other symptoms.
Further help and information
A quote from this site...."The norm for labyrinthitis is to last between 3 and 8 weeks and then disappear without so much of a trace. For a fair number however this does not happen.... This website is for those people who have been suffering for months and years rather than weeks."