What is Dystonia?

Dystonia is a neurological movement disorder. It is the term used to describe particular types of involuntary and abnormal movements and postures which are seen in a variety of neurological disorders. Dystonia can affect just one part of the body or several different areas.

 

Dystonia does not affect other normal functions of the brain.  For example, a person who has dystonia will generally have normal intellect, personality, memory, emotions, sight, hearing and sexual functions.

 

Who is affected by Dystonia?

Dystonia can affect both men and women of all ages.  When onset occurs in childhood, it is often particularly disabling. Dystonia which first shows symptoms in adult life, tends to remain focal, rather than becoming generalised.

 

Dystonia can be difficult to diagnose, which means that many patients remain untreated, their symptoms unrecognised. Recent epidemiological studies indicate that there are more than 500,000 people across Europe with some form of the disorder, many of whom are unaware that they have dystonia.

 

What are the different forms of Dystonia?

There are several different forms of dystonia, which may be classified as follows:

 

1.       Cause

·         Primary - includes familial dystonia with a known cause, as well as sporadic with no known cause.

·         Dystonia-plus Syndromes - dystonia with parkinsonism (including dopa-responsive) or myoclonus.

·         Secondary - e.g. caused by injury, side effects of medication or symptoms of another illness).

·         Heredodegenerative Diseases e.g. Wilson’s, Huntington’s, Mitochondrial or Parkinson’s Diseases.

 

2.       Age at Onset

·         Childhood onset            =    0 to 12 years

·         Adolescent onset          =  12 to 20 years

·         Adult onset                   =  >  20 years

 

3.       Part of Body Affected

·         Focal - affects only one part of the body

·         Segmental - affecting adjacent areas

·                   Hemidystonia -  arm  and  leg  on  one  side of  the  body

·         Multifocal - many different parts of the body

·         Generalised - most parts of the body

 

FOCAL DYSTONIA: e.g. muscles around the eyes, in the neck, in the throat or in one of the limbs.  

Common forms of focal dystonia include:

 

  • Cervical Dystonia (Spasmodic Torticollis): affects the neck muscles and causes the head to twist to one side (torticollis), forwards (anterocollis), backwards (retrocollis) or over one shoulder (laterocollis).  Cervical dystonia is the most common form of dystonia. It is often accompanied by a tremor or shake of the head.
  • Blepharospasm: affecting the muscles around the eyes, leading to excessive blinking or involuntary eye closure. Although eyes and vision may be normal, muscle spasms may cause functional blindness.
  • Oromandibular Dystonia: affects the muscles of the lower face,  jaw, tongue and mouth.
  • Meige's Syndrome: combination of Blepharospasm and Oromandibular Dystonia.
  • Hemifacial Spasm: can affect one eyelid and/or one side of the face. Technically is not a dystonia, but has many dystonic features. It can also be classed as “Unilateral Blepharospasm” or “Segmental Myoclonus”.
  • Laryngeal Dystonia (Spasmodic Dysphonia): affects the muscles of the larynx and vocal cords. The Adductor type causes the voice to sound strained and choked. The less-common  Abductor type produces a breathy, whispering sound.
  • Writer's Cramp: affects the muscles of the hand and forearm when writing. There are other focal dystonia which are triggered only by a particular activity or occupation. Examples include typist's cramp, golfer's cramp, musician's cramp (pianists, string, woodwind or brass players).

 

SEGMENTAL DYSTONIA: affects an area of the body such as the neck and an arm.

 

HEMIDYSTONIA: affects the arm and leg on one side of the body.

 

MULTIFOCAL DYSTONIA: affects many different parts of the body.

 

GENERALISED DYSTONIA: affects most parts of the body, especially the legs and trunk.

 

What are the causes of Dystonia?

The causes of this illness are not yet fully understood, but  in some cases, at least, it may be caused by a chemical imbalance in a particular area of the brain. The basal ganglia are structures deep in the brain that are in part responsible for controlling movement. They regulate the numerous muscle contractions that are necessary to move the body.  If this part of the brain is damaged in some way, the wrong muscles contract when we try to move or the muscles contract unnecessarily even when we do not move, causing uncontrollable twitching, tremor and contractions. These spasms are known as dystonic movements.

 

Some people, who live with dystonia, may have suffered from an illness or injury which has damaged the basal ganglia (secondary dystonia), but in the majority of cases the underlying cause of the condition is unknown.  If no cause can be identified, then the dystonia is said to be primary or idiopathic. 

 

Is Dystonia hereditary?

Dystonia which develops in childhood is often inherited through one or more affected genes. Primary segmental or generalised dystonia is often 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 had only a mild form of the illness and have never sought medical advice or their dystonia was misdiagnosed.

 

Which doctors can diagnose and treat Dystonia?

There are no specific tests, such as blood tests or scans, which determine whether a person has dystonia. As many family doctors are unfamiliar with Dystonia it has led to a large number of undiagnosed or wrongly-diagnosed patients. Therefore clinical examination by an experienced doctor is required and a neurologist specialising in movement disorders, an ophthalmologist for blepharospasm, or an ENT specialist (ear, nose and throat) for spasmodic dysphonia should be consulted. Lists of specialists can be obtained from the national dystonia societies.

 

What treatments are available?

A variety of treatments is available for dystonia, some which reduce the spasms and some which are effective in improving the patient's quality of life. These will be prescribed depending on the type and severity of the dystonia.  The main options are: drug therapy, injections of botulinum toxin or, in some cases, surgery.

 

Botulinum Toxin Therapy

Injections of purified botulinum toxin have become the treatment of choice for most dystonia patients. This therapy has been used with considerable success for the past twenty years to treat various forms of the condition, including blepharospasm, cervical dystonia, spasmodic dysphonia and writer's cramp.  Botulinum toxin acts on the junctions between the nerves and the muscles, preventing the release of one of the chemical messengers called acetylcholine from the nerve endings. This helps to reduce muscle contractions and the muscles then become weaker. Since however the nerve endings grow back, the dystonic symptoms return and the treatment has to be repeated, usually every two or three months. Any side effects are rarely serious and always temporary.

 

What other drug treatments are available?

Drugs are effective for some patients.  Some work by interfering with the neurotransmitters, which are chemical substances carrying messages in the central nervous system. Others are designed to relax the dystonic muscles, reduce tremor and control muscle spasms.  To be effective, drugs need to be taken on a continuous basis.

 

What surgical treatment is available?

Surgery is considered only for seriously affected patients for whom other forms of treatment have failed.  Surgical approaches include selective peripheral denervation for cervical dystonia, and thalamotomy and pallidotomy for generalised forms. Recent developments have seen promising results from a procedure known as Deep Brain Stimulation.  Careful patient selection for this treatment is paramount to its success.

 

What else can be done to help?

"Complementary" or "Alternative" treatments of many kinds like acupuncture, relaxation techniques, homeopathy, Feldenkrais, and hypnosis have been tried with varying degrees of success, but with little evidence of long-term benefit. Physiotherapy and speech therapy have proved to be invaluable in many cases.

 

Will Dystonia improve or get worse?

If dystonia develops in childhood, then in many (but not all) cases it will spread to other parts of the body and become generalised.  However, adult onset dystonia tends to have different characteristics and is generally confined to a local area (focal dystonia). It is unlikely to spread to other parts of the body. 

Dystonia can sometimes improve or disappear for no apparent reason. The likelihood of this happening is extremely rare and unpredictable. In some cases, the dystonia returns after a period of remission, but patients rarely remain symptom-free for the rest of their lives.

 

Is there a cure for Dystonia?

Unfortunately, there is no known cure for dystonia.  However, there is a range of treatments available to alleviate the condition. Great advances have been made in the area of dystonia genetics and much research continues around the world.

 

What are the main problems associated with Dystonia?

The symptoms of dystonia can often be painful and may vary in their severity from a minor inconvenience to a total interruption of normal life. However, two of the main problems experienced by people with dystonia are isolation and lack of awareness of the condition.  People with dystonia often feel embarrassed by the symptoms, which can be bizarre and disfiguring, and tend to avoid social contact. Family, friends and work colleagues may find it difficult to comprehend the problems of the patient. Even today dystonia is often still incorrectly considered to be a psychogenic disorder.

 

Why have I never heard of it?

Worldwide, dystonia is one of the most common movement disorders, alongside Parkinson's Disease and Tremor, yet few people have heard of it and fewer have any idea what it is. Dystonia is not a life-threatening disorder but, in its more serious forms, it can have a devastating effect on the life of patients and their families. 

 

One of the main activities of the European Dystonia Federation and its national member groups is its work to increase awareness of the condition among the public and the medical profession and to help patients find the best treatment available. Sharing information and experiences with other patients is another step forward to achieve the publicity dystonia needs.

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