Dystonia is a medical term that describes a range of movement disorders that causes involuntary spasms and contractions.
The movements are often repetitive and take on unusual and awkward postures. They can also be painful.
Dystonia is thought to be a neurological condition (conditions that are caused by underlying problems with the brain and nervous system). However, brain functions such as intelligence, memory and language are unaffected in most cases.
Types of dystonia
Dystonia can affect only one muscle or a group of muscles. There are five main types of dystonia:
- focal dystonia – only a single body part is affected, such as the hand or eyes
- segmental dystonia – two or more connected body parts, such as the neck and shoulder are affected
- multifocal dystonia – affects two or more parts of the body that aren’t connected to each other, such as the left arm and left leg
- generalised dystonia – both legs and other parts of the body are affected, usually one arm or both arms
- hemidystonia – dystonia that affects half of the entire body
The two most commonly affected areas are the neck muscles (cervical dystonia) and the eyelids (blepharospasm).
Read more about the symptoms of dystonia.
Causes of dystonia
If muscle spasms are the only symptom and there is no other associated condition, it is referred by doctors as primary dystonia.
This type of dystonia is usually inherited, although most people don’t have a specific family history. It is caused by a problem with a part of the brain that controls muscle movement (the basal ganglia).
Dystonia that occurs as a symptom of an underlying condition or injury is referred to as secondary dystonia. Common causes of secondary dystonia are stroke, brain injury, encephalitis (infection of the brain) and Parkinson’s disease.
Read more about the causes of dystonia.
Dystonia is diagnosed by examining the physical symptoms. However, some tests may be required to find out whether you have primary or secondary dystonia as this can affect the way the condition is treated.
Treating dystonia
There’s no cure for dystonia, although the symptoms can be managed with treatment.
In some cases of secondary dystonia, such as after a stroke, the symptoms eventually disappear completely. This is called remission, and occurs in around 10% of people with focal dystonia during their lifetime. However, people with other underlying conditions, such as Parkinson’s disease, are likely to have symptoms of dystonia that last for the rest of their lives.
Treatment options for dystonia will vary depending on the type of dystonia you have. They can include:
- medication – such as levodopa to increase levels of dopamine (a chemical that affects voluntary movement) in the brain; botulinum toxin, which stops muscle spasms; muscle relaxants such as diazepam
- physical therapy – to try to improve posture and stop muscles from weakening
- surgery – cutting nerve endings that are causing spasms (selective peripheral denervation) or using a small pulse generator implanted under your skin to block nerve impulses (deep brain stimulation)
Read more about how dystonia is treated.
How common is dystonia?
Generally, dystonia is an uncommon condition. However, it’s one of the more common neurological conditions. The Dystonia Society estimates that at least 70,000 people in the UK are affected by dystonia. At least 8,000 of them are children and young people.