Dystonia explained
The following information is taken from our factsheet, Dystonia explained.
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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. It is a neurological disorder that affects movement, but does not lead to problems with other functions of the brain such as intellect.
How many different types of dystonia are there?
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 and sometimes other hand-based tasks. - Cranial dystonia (Miege's syndrome)
dystonia affecting the muscles around the eyes in addition to those in the jaw, tongue and mouth
affects 2 adjoining parts of the body such as the neck and an arm.
HEMIDYSTONIA
affects an arm and a leg on one side of the body.
MULTIFOCAL DYSTONIA
affects many different parts of the body.
GENERALISED DYSTONIA
affects most of the body, frequently involving the legs and back (trunk).
There are other rare forms of dystonia including:
PAROXYSMAL DYSTONIA
dystonia affecting the whole or part of the body in brief episodes.
MYOCLONUS DYSTONIA
where sudden jerking movements occur with dystonia.
Who is affected by dystonia?
Dystonia affects men and women of all ages. If it develops in childhood, it tends to become generalised. 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. Indeed, until recently, many GPs were unfamiliar with the condition. However, 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, 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, or 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 passin gthe 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. They may have never sought medical advice or perhaps 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?
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.
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 challenges that their condition brings. Successful treatments to lessen their symptoms, effective pain control and the acquisition of sensory 'tricks' all help to ameliorate social situations.
What forms of treatment are available?
Various treatments are available for dystonia. These will be determined depending upon the type and severity of the particular condition. The main options are:
- drugs
- botulinum toxin
- surgery
For more information, see our Treatments section.