Dystonia

Page last reviewed: 13/07/2011

Dystonia is a general term that describes a range of movement disorders which cause involuntary muscle spasms and contractions (tightening). The spasms and contractions that are associated with dystonia can cause the affected body parts to make repetitive movements and take on unusual and awkward postures.

Dystonia is thought to be a neurological condition, i.e. a condition that is caused by underlying problems with the nervous system and brain. However, in most cases, other functions of the brain, such as intelligence, memory and language are unaffected.

How common is dystonia?

Generally, dystonia is an uncommon condition. However, it is one of the most common neurological conditions. An estimated 3000 people in Ireland are affected by dystonia.

Dystonia can affect people of all ages, including children. However, symptoms most commonly begin when a person is between 40 and 60 years old.

Types of dystonia

The various types of dystonia can be classified in three different ways:

  • by the underlying cause
  • by the part of the body that is affected
  • by the age that the symptoms begin

Dystonia by cause

Primary dystonia

Primary dystonia is a term that describe cases where dystonia is the only symptom, and there is no evidence of any other associated neurological disease or damage.

Secondary dystonia

Secondary dystonia is a term that is used to describe cases where dystonia arises as a symptom of an underlying neurological or genetic condition, or from damage to the brain and/or nervous system. Some common causes of secondary dystonia include:

  • stroke
  • brain injury
  • encephalitis (infection of the brain)
  • Parkinson's disease

Parkinson's disease is a chronic (long-term) condition that affects the way the brain co-ordinates body movements, including walking, talking and writing.

Dystonia by body part

There are five main ways that dystonia can affect the body:

  • focal dystonia - dystonia only affects a single body part, such as the hand or the eyes
  • segmental dystonia - dystonia affects two or more regions of the body that are connected to each other, such as the neck and the shoulder
  • multifocal dystonia - where dystonia affects two or more regions of the body that are not connected to each other, such as the left arm and the left leg
  • generalised dystonia - dystonia affects both legs and other regions of the body (usually one arm or both arms)
  • hemidystonia - dystonia affects half of the entire body

Dystonia by age

Early-onset dystonia

Early-onset dystonia is a term that is used to describe cases of dystonia where the symptoms begin in childhood or early adulthood (usually between 5-30 years of age). Early-onset dystonia usually begins in a leg or arm before often spreading to other limbs and/or the torso (the upper part of the body, excluding the head and limbs).

Late-onset dystonia

Late-onset dystonia is a term used to describe cases of dystonia when symptoms of dystonia begin in middle age, usually between the ages of 40 and 60. In most cases of late-onset dystonia, symptoms begin in the neck, head or one of the arms, and usually do not progress any further.

Outlook

The outlook for cases of primary dystonia can be unpredictable. The condition is not life-threatening but it is incurable. Despite this, many people with primary dystonia can, with treatment, control or at least reduce the severity of their symptoms. Treatment options for dystonia include medication, physical therapy and surgery.

The outlook for cases of secondary dystonia depends on the corresponding outlook of the underlying condition. For example, people who have had a stroke sometimes experience full remission from the symptoms of dystonia. But people with Parkinson's disease are likely to have symptoms of dystonia for the rest of their lives.

Page last reviewed: 13/07/2011

The symptoms of dystonia can vary depending on the form of dystonia that you have. Some forms of dystonia and their associated symptoms are described below.

Cervical dystonia  

Cervical dystonia is the most common form of dystonia. It is a type of focal (it only affects one body part) late-onset dystonia that affects the muscles in your neck. Cervical dystonia is sometimes known as torticollis.

Contractions and spasms in your neck muscles can lead to symptoms such as:

  • your head and neck twisting
  • your head and neck being pulled forward
  • your head and neck being pulled backwards
  • your head and neck being pulled from side to side

The symptoms of cervical dystonia can range from mild to severe. The symptoms of muscle spasms and contractions can lead to the additional symptoms of neck pain and stiffness.

The symptoms of cervical dystonia can often be relieved by touching your chin, neck or the back of your head. The reasons for this are unclear.

Blepharospasm

Blepharospasm is a type of focal, late-onset dystonia that affects the muscles around your eyes.

Symptoms of blepharospam include:

  • eye irritation
  • sensitivity to light (photophobia)
  • uncontrollable blinking
  • uncontrollable closing of the eyes - in the most severe cases, a person cannot open their eyes for several minutes, effectively making them blind for short periods of time.

If you have blepharospasm, the pattern of your symptoms can vary during the day. You may have few or no symptoms when you wake up in the morning, but then your symptoms get worse when you are tired or under stress.

Dopa-responsive dystonia

Dopa-responsive dystonia is a type of generalised, early-onset dystonia. The term 'dopa-responsive' is used because this type of dystonia is known to respond well to treatment with a medication called levodopa.

The symptoms of dopa-responsive dystonia usually begin during childhood, between ages 6 and 16. The most common symptom is an abnormal, stiff way of walking. The sole of the foot can also bend upwards, or the foot may turn outwards at the ankle.

Some people with dopa-responsive dystonia may also have muscle stiffness and spasms in their arms and torso.

Hemifacial spasm

Hemifacial spasm is a type of focal, late-onset dystonia that causes the muscles on one side of the face to spasm. You may find that this symptom is more prominent and troublesome when you are tired or under stress.

Laryngeal dystonia

Laryngeal dystonia is a type of focal, late-onset dystonia that causes the muscles of the larynx (voice box) to spasm depending on whether the muscles of the larynx are spasming outwards or inwards.

This can cause your voice to take on either a 'strangled' quality or a very quiet, 'breathy' quality.

Myoclonus dystonia

Myoclonus dystonia is a rare type of segmental, late-onset dystonia that affects the muscles in the arms, neck and torso (the upper part of the body, excluding the head and limbs). It causes sudden 'jerk-like' spasms that appear very similar to the spasms that someone has when they get an electric shock.

Oromandibular dystonia

Oromandibular dystonia is a type of segmental, late-onset dystonia that affects the muscles in the mouth and jaw. This can cause your mouth to pull outwards and upwards.

In some cases, symptoms will only occur when you are using your mouth, such as while eating and talking. In other cases, symptoms can occur when you are not using your mouth. You may find that talking and chewing improves your symptoms.

If you have oromandibular dystonia, you may also have difficulties in swallowing (dysphagia).

Writer's cramp

Writer's cramp is a type of late-onset, focal dystonia that causes involuntary cramps and movements in the muscles of the arm and wrist. As the name suggests, writer's cramp usually affects people who do a lot of writing, so this type of dystonia is known as task-specific dystonia.

Other less well known types of task-specific dystonia include:

  • musician's cramp
  • golfer's cramp
  • typist's cramp

Generalised dystonia

Generalised dystonia is a type of early-onset dystonia that usually begins around the time that a child reaches puberty. The symptoms of generalised dystonia usually begin in one of the limbs before spreading to other parts of the body.

Symptoms of generalised dystonia include:

  • muscle spasms
  • the limbs or torso can take on an abnormal, twisted posture
  • a foot, leg or arm can turn inwards
  • body parts can jerk rapidly

Paroxysmal dystonia

Paroxysmal dystonia is a rare type of dystonia in which the muscle spasms and unusual body movement only occur at certain times. The rest of the time you remain symptom-free.

The symptoms of paroxysmal dystonia can resemble some of the physical symptoms of an epileptic seizure (fit). The sudden onset of symptoms is known as an attack. During an attack, only your muscles will be affected. Unlike epilepsy, you will not lose consciousness and you will remain fully aware of your surroundings. Attacks can last anywhere from a few minutes to several hours.

Certain situations or substances can trigger an attack, including:

  • stress
  • fatigue
  • alcohol
  • coffee
  • sudden movement

Page last reviewed: 13/07/2011

Primary dystonia

It is thought that most cases of primary dystonia are caused by problems with a part of the brain known as the basal ganglia.

The basal ganglia is a collection of brain cells at the front of the brain. They are responsible for sending messages from the brain to various muscles in order to move them. This is done by using special, messenger-chemicals known as neurotransmitters.

In cases of primary dystonia, it is thought that the basal ganglia does not produce enough neurotransmitters, or it produces the wrong type of neurotransmitters, resulting in problems with muscle function.

In cases of early-onset dystonia, it appears that the basal ganglia does not develop in the right way due to mutated (altered) genes that you inherit from your parents.

Twelve types (or sub-types) of dystonia are currently linked to genetic mutations. They include:

  • generalised dystonia
  • dopa-responsive dystonia
  • paroxysmal dystonia

The genes responsible for these types of dystonia are passed down through families in a pattern that is known as autosomal dominant. This means that if you have one of these abnormal genes, there is a 1 in 2 chance that your children will inherit that gene and develop dystonia.

Late-onset primary dystonia is a poorly understood condition and its cause (or causes) are unknown.

Secondary dystonia

Secondary dystonia can have a wide range of causes, including:

  • Parkinson's disease - a neurological (brain-related) condition that is caused by a lack of a neurotransmitter called dopamine
  • Huntington's disease - a genetic (inherited) condition that is caused by a lack of cholesterol in the brain
  • Wilson's disease - a genetic condition that leads to a build-up of copper in the tissues of the body
  • multiple sclerosis - a condition that is caused by damage to the nervous system
  • cerebral palsy - a condition caused by brain damage that occurs before or quickly after birth
  • certain medications, such as the one used to treat epilepsy, can cause dystonia as a side effect in a small number of people
  • infections such as HIV or encephalitis (infection of the brain)
  • injury to the skull or spine
  • brain tumours
  • stroke
  • poisoning, such as carbon monoxide poisoning

Page last reviewed: 13/07/2011

In most cases, a confident diagnosis of dystonia can be made by making a visual examination of your physical symptoms. However, this is only the first step in the diagnosis process.

It is important to confirm whether your dystonia is primary or secondary. Secondary dystonia is dystonia that has been caused by an underlying health condition, injury or some other type of damage.

Confirming the type of dystonia is important because the treatment of secondary dystonia can vary from that of primary dystonia, depending on the underlying cause. Treating the underlying cause can in turn help to control symptoms of secondary dystonia.

Primary or secondary dystonia is usually confirmed by doing a series of tests and examinations. These are listed below.

  • You are asked about your recent medical history and your family history. For example, whether you have recently suffered a head injury, or whether you have a relative who has developed dystonia.
  • Blood and urine tests check the function of your organs, such as your liver, and see whether you have an infection or high levels of toxins in your body.
  • Genetic testing: a sample of DNA can be taken from your blood and checked to see whether you have any of the abnormal genes associated with some types of dystonia; genetic testing can also confirm whether or not your dystonia is caused by a genetic condition, such as Huntington's disease.
  • A magnetic resonance (MRI) scan checks whether there is any damage to your brain, or whether you have a condition that is affecting your brain, such as a tumour.

If you have early-onset dystonia, you may also be given a course of medication called levodopa. If your symptoms suddenly improve after taking levodopa, a confident diagnosis of dopa-responsive dystonia can be made.

Page last reviewed: 13/07/2011

Medication

Levodopa

If you are diagnosed with dopa-responsive dystonia, a medication called levodopa is the treatment of choice.

Levodopa works by increasing the levels of a neurotransmitter in the brain called dopamine. This should help to control your dystonia symptoms.

Nausea is the most common side effect of levodopa. However, this side effect should improve as your body starts to get used to the medication.

Less common but potentially more troublesome side effects of levodopa include:

  • feeling dizzy when you stand up
  • lack of appetite
  • changes in mental states, such as feeling anxious, confused or disorientated (lost)
  • having an compulsive need to gamble
  • vomiting
  • diarrhoea

Tell your GP if you have any of these less common side effects. Your dosage may need to be adjusted.

Levodopa is not usually recommended if you are pregnant because there is not enough evidence that it is safe to take during pregnancy. If you are pregnant, or you are thinking about becoming pregnant, discuss with your GP the potential risks of continuing to take levodopa.

Levodopa should not be taken if you are breastfeeding as it can be passed through your breast milk and may adversely affect your baby.

Botulinum toxin

Botulinum toxin is usually used as a first-line treatment for most other types of dystonia. It is a powerful poison that is clinically safe when used in minute doses.

Botulinum toxin stops the neurotransmitters that are responsible for muscle spasms from reaching the affected muscles. It is given by injection directly into the affected muscles.

The effects of the injection usually last for three months after which time you will need a further injection. The site of the injection may feel painful for a few days, although this should soon pass.

Other side effects of botulinum toxin will depend on which part of the body was injected. For example:

  • injections in the neck region may lead to swallowing difficulties
  • injections around the eyes may lead to drooping of the eyes and/or double vision
  • injections in the vocal cord may cause your voice to become soft and 'breathy'

These types of side effects should pass within about a week.

Anticholinergics

Anticholinergics are a type of medication that treat some types of focal dystonia. However, they are not effective for everyone.

Anticholinergics work by blocking the release of a neurotransmitter called acetylcholine, which is known to cause muscle spasms in some cases of dystonia.

Side effects of anticholinergics include:

  • dry mouth
  • constipation
  • difficulties urinating
  • blurred vision
  • memory problems
  • confusion

Muscle relaxants

Muscle relaxants are a type of medication that is sometimes used to treat cases of dystonia that fail to respond to other types of medication.

Muscle relaxants work by increasing the levels of a neurotransmitter called gamma-aminobutyric acid (GABA), which helps to relax affected muscles. Diazepam and clonazepam are two types of muscle relaxants that are used to treat dystonia.

Depending on the pattern of your symptoms, muscle relaxants can be given by injection (intravenously) or in tablet form (oral).

Side effects of muscle relaxants include:

  • tiredness
  • muscle weakness
  • dizziness
  • impaired co-ordination

These side effects should be temporary and disappear once your body gets used to the medication. If you have symptoms of dizziness, avoid driving and operating heavy machinery.

Do not suddenly stop taking muscle relaxants. If you do you will have withdrawal symptoms, such as:

  • anxiety
  • tension
  • sweating
  • tremor (shaking)

If a decision is taken to stop treatment with muscle relaxants, your dose will be reduced gradually.

Physical therapy and 'sensory tricks'

Many people with dystonia find that they can significantly improve their symptoms by touching the affected body part, or a nearby area. This is known as a sensory trick.

For example, people with cervical dystonia (dystonia) often find that they can improve their symptoms by touching the back of their head, or the side of their face.

In some cases, it is possible to replicate the effects of these sensory tricks by using splints and braces to support the affected body parts.

Physical therapy is also an effective way of helping you to improve your posture and prevent the shortening or weakening of affected muscles. This can be done using a combination of exercise and braces.

Your GP should be able refer you to a physiotherapist. Alternatively, there are many private physiotherapists available. The Irish Society of Charted Physiotherapists web site has details of physiotherapists in your local area.

Surgery

Surgery may be recommended if your dystonia fails to respond to medication. A number of different surgical techniques can be used. They are described below.

Selective peripheral denervation

Selective peripheral denervation is a type of surgery that can be used to treat cervical dystonia.

During surgery, the surgeon will make an incision (cut) in your neck, before cutting some of the nerve endings which are connected to muscles that are prone to spasms. The surgery is performed under general anaesthetic, so you will be unconscious throughout the procedure.

Following the procedure, you will experience some loss of feeling in your neck due to the nerves being disconnected.

Generally, selective peripheral denervation is a safe type of surgery and complications are rare. It includes:

  • post-operative infection in the neck
  • short-term swelling of the neck
  • a feeling of 'pins and needles' in the neck
  • occasional short bursts of pain in the neck

Deep brain stimulation

Deep brain stimulation is a type of brain surgery that can be used to treat dystonia. During surgery, small holes are drilled into your skull. The surgeon will then thread a set of tiny electrodes through the holes and place them into a part of the basal ganglia called the globus pallidus.

The electrodes are connected to a small pulse generator, which is similar to a pacemaker, and is implanted under your skin, usually on your chest or lower abdomen.

The pulse generator sends signals to the globus pallidus. These signals help to block the abnormal nerve impulses produced by the basal ganglia, which lead to the symptoms for dystonia.

The most common complication of deep brain stimulation is that either the pulse generator stops working or the electrodes become displaced, which may require further surgery to correct.

As deep brain stimulation is a new technique, there is little information regarding its long-term safety or effectiveness. You should therefore discuss the risks and benefits of surgery with your surgical team.

If you have deep brain stimulation, it is likely that you will require a series of follow-up appointments because in most cases the signals produced by the pulse generator need to be adjusted in order to control your symptoms better.

It may be several weeks or months before you begin to feel the maximum benefit of deep brain stimulation.

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

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