Dystonia is a general term that is used to describe a range of movement disorders that cause involuntary muscle spasms and contractions (tightening). The spasms and contractions that are associated with dystonia can cause the affected body parts to experience repetitive movements and to take on unusual and awkward postures.
Dystonia is thought to be a neurological condition - that is, 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. It is estimated that there are 38,000 people in the UK who are affected by dystonia.
Dystonia can affect people of all ages, including children. However, most commonly, the symptoms begin when a person is between 40-60 years of age.
Types of dystonia
There are three ways that different types of dystonia can be classified. These are:
- by the underlying cause,
- by the part of the body that is affected, and
- by the age that the symptoms begin.
Dystonia by cause
Primary dystonia
Primary dystonia is a term that is used to 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), and
- Parkinson’s disease.
Parkinson’s disease is a chronic (long-term) condition that affects the way that the brain coordinates body movements including walking, talking, and writing.
Dystonia by body part
There are five main ways that dystonia can affect the body:
- focal dystonia - where dystonia only affects a single body part, such as the hand or the eyes,
- segmental dystonia - where 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 - where dystonia affects both legs and other regions of the body (usually one arm or both arms), and
- hemidystona - where 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 40-60 years old. In most cases of late onset dystonia, symptoms begin the neck, the head or one of the arms, and usually do not progress any further.
Outlook
The outlook for cases of primary dystonia can be unpredictable. While the condition is not life-threatening it is also incurable. Despite that fact, many people with primary dystonia are able to control, or at least reduce the severity of their symptoms, with treatment. 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 experienced a stroke can sometimes experience full remission from the symptoms of dystonia while people with Parkinson’s disease are likely to experience symptoms of dystonia for the rest of their life.