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What is dystonia?

Dystonia is the term used to describe involuntary sustained muscle contractions that lead to abnormal movements and postures. Dystonia can affect just one part of the body or several different areas.

Dystonia is a neurological disorder that affects movement, but does not lead to problems with other functions of the brain such as intellect, vision and hearing, sensation and sexual function.

What are the different types of dystonia?

Some of the more common types of dystonia include:

FOCAL DYSTONIA

Focal dystonias are the most common form and affect only one part of the body. They include:

  • Cervical dystonia (also known as spasmodic torticollis): dystonia of the neck muscles which causes the head to twist, pull in one direction, or shake
  • Blepharospasm: dystonia of the muscles around the eyes
  • Oromandibular dystonia: dystonia affecting the muscles of the jaw, tongue and mouth
  • Laryngeal dystonia: dystonia affecting the speech muscles
  • Writer's cramp: dystonia affecting the ability to write
  • Cranial dystonia (Meige's syndrome): dystonia affecting the muscles around the eyes in addition to those in the jaw, tongue and mouth

SEGMENTAL DYSTONIA

This affects an area of the body two or more body parts close to each other, such as the neck and an arm.

HEMIDYSTONIA

This affects an arm and a leg on the same side of the body.

MULTIFOCAL DYSTONIA

This affects two or more unrelated parts of the body.

GENERALISED DYSTONIA

This affects most of the body, frequently involving the legs and back (trunk).

Who is affected by dystonia?

Dystonia affects men and women of all ages. If it develops in childhood, it tends to become generalised and can be particularly disabling. Dystonia which has its onset in adult life usually remains focal and is more common in those over 40 years of age.

Dystonia can be difficult to diagnose and many patients remain untreated because their symptoms are unrecognised. It is thought that there are more than 40,000 people with dystonia in the UK.

Why have I never heard of dystonia?

Even though dystonia is estimated to be about ten times more common than motor neurone disease, many people have never heard of it. In the last few years, awareness of dystonia has increased and the outlook for people with dystonia is improving. The Dystonia Society, a registered charity, works hard to speed up the processes of both research and recognition.

What are the causes of dystonia?

The causes of dystonia are still not fully understood, but there appears to be a problem in an area of the brain called the basal ganglia, which is involved in controlling movement. It has been suggested that an imbalance of neurotransmitters (such as dopamine) leads to this defect in control of muscles and movement.

In some cases, damage to the basal ganglia can lead to dystonia. These are referred to as secondary dystonia and can be due to a variety of causes such as stroke or tumour of the basal ganglia, the result of certain drugs (especially dopamine blocking drugs used to treat psychiatric disorders) and so on. In the majority of cases, no underlying cause is found apart from possible genetic factors, and these are called primary or idiopathic dystonia.

Is it inherited?

Dystonia that develops in childhood is often inherited through one or more affected genes. Most primary segmental or generalised dystonia is inherited in a dominant manner, which means that if a parent has this type of dystonia, there is a 50% chance of passing the dystonia gene to each child. However, not everyone who inherits the gene develops dystonia, a phenomenon known as reduced penetrance.

Dystonia which develops in adults may also be inherited. This is often difficult to identify, since other family members may have only a mild form of the illness and have never sought medical advice or their dystonia was misdiagnosed.

What should I do if I think I have dystonia?

If you think you may have dystonia and it has not yet been diagnosed, you should see your doctor and ask to be referred to a neurologist specialising in movement disorders. If you are diagnosed as having blepharospasm, you may be treated by an ophthalmologist. If you have laryngeal dystonia, you may see an ear, nose and throat (ENT) specialist.

Will my dystonia improve or get worse?

In many cases, if dystonia develops in childhood, particularly if it starts in the legs, it may spread to other parts of the body, and can become generalised. However, when it develops in adults, it usually confines itself to one part of the body (focal dystonia). If it spreads at all - which is unlikely - it will usually affect only one other area, usually in the nearest muscle group.

The progress of dystonia is unpredictable. The severity of symptoms can vary from day to day, and while there often is an element of overall progression, it is difficult to estimate how long this will last. Typically, a focal dystonia will progress very gradually over a five-year period, and then progress no further. Symptoms in all dystonic conditions can vary.

For some people, their dystonia may sometimes improve or disappear altogether for no apparent reason. The likelihood of a total remission of symptoms has been estimated as somewhere between one-in-ten and one-in-twenty. In some cases, the dystonia may eventually return, but in others it will disappear completely.

Is there a cure for dystonia?

Unfortunately, there is not yet a cure for most forms of dystonia. Nowadays, however, many dystonic conditions can be very successfully managed.

What forms of treatment are available?

A variety of treatments are available for dystonia. These will be determined depending upon the type and severity of the particular condition. The main options are:

  • drug therapy
  • injections of botulinum toxin
  • surgery

DRUGS

Drugs are effective for some patients. Some work by interfering with neurotransmitters, the chemical substances that carry messages within the brain. Others are designed to relax the muscles, reduce shaking and control muscle spasms. To be effective, they have to be taken continuously. The following drugs could be prescribed: diazepam; clonazepam; baclofen; carbamazepine; levodopa; tetrabenazine. Those drugs which have been used in the past but are rarely used nowadays include: bromocriptine; chlorpromazine; haloperidol; pimozide; amantadine.

BOTULINUM TOXIN

Botulinum toxin injections are an effective treatment for dystonia where it affects the muscles of the neck or around the eyes. In some cases, other forms of dystonia can benefit from the treatment. The substance injected is a purified form of the toxin that causes botulism. It works by acting on the junctions between nerves and muscles, preventing the release of one of the chemical messengers - acetylcholine - from the nerve endings. This reduces muscle contractions and causes the overactive muscles to weaken. The nerve endings recover after eight or nine weeks, and so the treatment has to be repeated, usually after a three month interval. For further information on botulinum toxin therapy and possible side effects of the treatment, see Botulinum toxin injections - your questions answered.

SURGERY

Surgery may be an option where patients are no longer receptive to other treatments. (Resistance to botulinum toxin can develop in a minority of patients over a period of time.) Surgical treatments include selective denervation and deep brain stimulation (DBS). In the case of the latter, electrodes are planted in the basal ganglia to help 'rebalance' movement and to control posture. Some recent research has led to a refinement in the placing of electrodes for optimum effect.

How do I live with dystonia?

As with the onset of any long-term medical condition, some people who develop dystonia may go through an initial period of depression, embarrassment and outrage - or relief that there is an explanation for their symptoms. Most people do manage to develop effective strategies for coping with the problems their condition brings. With successful treatments to lessen their symptoms, effective pain control and the acquisition of one or two social 'tricks' to help overcome any social awkwardness, they rapidly recover from the first impact. In any social situation, dystonia will not often get in the way if it is quickly explained and then 'forgotten about'.

The disability that can follow from the onset of dystonia may bring substantial practical difficulties.

What can the Dystonia Society offer?

The Dystonia Society is dedicated to providing information and support to everyone affected by dystonia in the UK and to raising awareness of the condition and the needs of everyone affected. The Society is committed to ensuring that everyone with dystonia has access to the treatments they need.

The Dystonia Society has a Helpline (tel: 0845 458 6322) that is open Mondays - Fridays between 10am - 4pm and offers an opportunity to discuss concerns in confidence, and to obtain information on dystonia and its various treatments, including ways of making living with dystonia easier.

Local support is provided via the Dystonia Society's regional support groups run by the Society's team of volunteers.

The Dystonia Society encourages and supports research into potential treatments and practical ways of coping with the condition.

You may want to join the Dystonia Society - become a member and receive their quarterly newsletter. Call: 0845 458 6211.

The Dystonia Society logo

Helpline: 0845 458 6322

Website: www.dystonia.org.uk