Dystonia

Dystonia is a neurological movement disorder characterized by involuntary muscle contractions, which force certain parts of the body into abnormal, sometimes painful, movements or postures. Dystonia can affect any part of the body including the arms and legs, trunk, neck, eyelids, face, or vocal cords.

If dystonia causes any type of impairment, it is because muscle contractions interfere with normal function. Features such as cognition, strength, and the senses, including vision and hearing are normal. While dystonia is not fatal, it is a chronic disorder and prognosis is difficult to predict. It is the third most common movement disorder after Parkinson's Disease and Tremor, affecting more than 300,000 people in North America. Dystonia does not discriminate - affecting all races and ethnic groups.

The condition is due to malfunction of the central nervous system, probably in those parts of the brain called the basal ganglia. In primary (or ‘idiopathic’ torsion) dystonia no other functions of the brain are involved and investigations reveal no identifiable cause. In a minority of cases, specialised tests can identify known causes that damage the basal ganglia, and the dystonia in these cases is called ‘secondary’ or ‘symptomatic’.

Based on the above definition, there are a number of dystonic syndromes which can be subdivided according to their clinical features as either:

a) generalized (affecting all body parts)

b) segmental (affecting adjacent body parts)

c) focal (restricted to a single body part)

Focal dystonias include spasmodic torticollis, blepharospasm, hemifacial spasm, spasmodic dysphonia, and dystonic writer's cramp.

Segmental and Generalised Dystonia (Dystonia musculorum deformans). The majority of cases are idiopathic (that is, the cause of the dystonia is unknown) and usually start in childhood in one limb (often the foot). It can spread to involve other parts of the body, including the back, neck and arms.

Dopa-responsive Dystonia (Segawa’s disease).

Originally described in Japan, this much rarer condition is also seen in Europe and the U.S.A. Again it usually starts in childhood or adolescence with dystonia and stiffness similar to that seen in Parkinson’s disease, and symptoms often worsen as the day progresses. Treatment with the drug L-Dopa may almost completely relieve the symptoms, and effectiveness appears to last indefinitely.

SECONDARY ("Symptomatic") DYSTONIA

In this type of dystonia, the symptoms are due to small areas of brain damage. The dystonia is often segmental, generalised, or hemidystonia. The damage can be caused by reduced oxygen around the time of birth (cerebral palsy), by injury to the brain, or by small strokes or tumours. Dystonia can also occur in more widespread nervous system conditions such as Wilson’s disease, encephalitis, and so on.

In some cases dystonia can be caused as a side-effect of treatment with neuroleptic drugs; this is known as tardive dystonia.

Hemifacial Spasm is different from true dystonias in that it seems to result from irritation of the facial nerve. It is a movement disorder that causes the muscles on one side of the face to contract.

How is Dystonia Diagnosed?

Dystonia is pretty rare. Primary care physicians may have not seen it before therefore making it difficult for them to diagnose. Additionally, the movements and postures of dystonia may increase or decrease with stress and emotions. The best thing to do is for your doctor if he or she suspects dystonia or simply doesn't know what you have is to refer you to a neurologist who specializes in movement disorders.

Will People with Dystonia Ever Get Better?

About 10 - 15% of patients with Dystonia experience temporary (or occasionally even permanent) "remission". Why this happens, to whom it will happen, or when it will happen cannot yet be predicted. This is really important because it shows that the brain in dystonia may not be damaged permanently.

What Does Age Have To Do With It?

When primary dystonia starts in childhood or adolescence, it usually affects the legs first, and it is likely (though not 100%) that the dystonia will spread and become generalised.

To the contrary, when dystonia first shows itself as an adult it is usually one of the focal forms and tends to remain limited to that part of the body.

IS DYSTONIA INHERITED?

The fact that sometimes more than one member of a family develops dystonia, makes it clear that inheritance plays an important. Most cases of primary segmental and generalised dystonia are due to a gene inherited in a dominant manner. Many cases of dopa-responsive dystonia are inherited in this way. Dominant’ means that each child of a parent who carries the abnormal gene has a 50/50 chance of inheriting that gene.

A number of different genes on different chromosomes have now been identified as being linked with different types of dystonia, but researchers don’t yet know exactly how a particular gene causes dystonia.

CAN DRUGS HELP DYSTONIA?

The answer to this question is two-folded. If the problem is mild, it may be best to avoid drug treatment. The reason being is that the drugs need to be taken continously and for long period of time. The problem with that is that all drugs can cause unwanted side-effects. It can be said that no drugs can cure dystonia, yet!

However, if the dystonia is your life, the way you function both at work and socially, then drug treatment may be recommended to try to control the muscle spasms. Unfortunately drug treatment is really never 100% effective, and many people don't get a lot of relief. Another problem is that there is not just one drug that will treat all patients with dystonia. Usually, children respond better than adults to medication.

WHAT TREATMENT IS AVAILABLE?

For many patients with focal dystonias, including blepharospasm, spasmodic torticollis, oromandibular dystonia, laryngeal dystonia and sometimes writer’s cramp, injections of botulinum toxin to temporarily weaken the muscles involved have become a very effective treatment.

Botulinum toxin is usually most effective if the dystonia affects only a limited group of muscles. Generally the injections need to be repeated every 3 or 4 months, though this may vary from person to person. The injections are available in certain neurology, ophthalmology, and ENT clinics.

Alternative therapies such as Acupuncture, Physical Therapy, Homeopathy etc. do not do much according to reports.

Is Surgery and Option?

Surgery is occasionally a "last resort", but often does nothing and is destructive. Usually, surgery is not recommended unless everything else has been tried and nothing else helps.

HOW CAN A PATIENT WITH DYSTONIA BE HELPED?

Of course the medication and possibly ultimately surgery have to be considered. However, a positive attitude is important.

Dystonia in itself is not a life-threatening condition, but its more severe forms can have a devastating effect on a patient’s quality of life, often causing considerable pain, affecting the individual's ability to work and the whole family’s everyday life and social activities. It is important that the individual's caregivers and loved ones support them at all times. Support groups with fellow sufferers also work well.