Clinical features
Focal Dystonias
Blepharospasm
This type of dystonia affects the eye muscles making blinking abnormally frequent or prolonged. The eyes may uncontrollably and repeatedly close for seconds at a time. Symptoms may be very variable being absent some of the time and extremely severe at other times. Factors likely to make symptoms worse include bright or flickering light, smoke, wind and air conditioning systems. Stress and anxiety can worsen the muscle spasms. The eyes can also feel uncomfortable or painful. Watching television, walking around or reading may be impossible. In severe cases blepharospasm can make a person functionally blind. Most commonly affects people between 50 and 70 years of age. People with this condition may become anxious, avoid social contact, become depressed or lose their employment because of the condition. When blepharospasm occurs with Oromandibular dystonia this is called Meige’s Syndrome.
Oromandibular dystonia (cranial dystonia)
This condition is characterised by abnormal spasms and movements of the cheeks, lips and tongue and jaw. These most commonly occur when someone is speaking or eating. People with this condition may become self conscious and avoid social contact and become depressed because of their condition.
Spasmodic dysphonia or laryngeal dystonia
This type of dystonia affects the muscles controlling the vocal cords. The vocal cords are held together under tension during normal speech, held in this way they vibrate to produce sound. Dystonia can either force the cords together so it is difficult for them to vibrate and the voice sounds strangled and difficult. Or it can pull them apart so the voice sounds breathy and weak. For some people the condition is an annoyance, for those who use their voice for work it is very disabling. Even when very severe, breathing is never affected.
Spasmodic torticollis or cervical dystonia
Torticollis literally means ‘twisted neck’. The term torticollis is used to cover a variety of abnormal head and neck movements which are better described by the term 'cervical dystonia’ – a term which means abnormal tone or movement of muscles in the neck. In this condition the muscles of the neck may be contracted all the time or contract in spasms, the most common abnormal position for the head is turned and bent to one side. There are different terms for abnormal positions of the head including laterocollis – ear positioned towards one shoulder, Retrocollis – head pulled backwards, anterocollis – head held bent forwards etc. The head position may change over time and the condition may involve both spasm of muscles and tremor - for example the tremor may consist of continually nodding for ‘no’ or nodding for ‘yes’ type movements.
The most common symptom is head turning (80%). Head shaking occurs in 50% of cases. In 25% the head is held in an abnormal posture all the time. Like other dystonias it may occur in episodes at first and get worse over several years becoming present all the time. In younger people who have had it for less than five years there is a 10-15% chance of the disease remitting although in most the condition returns with time.
Around 50% of people report that the condition is very painful. Pain is more common in people who have had the condition for longer. In a severe case the head is likely to be held painfully in an abnormal position or the tremor is severe making activities involving directed gaze difficult. Mental health problems and social isolation may arise because of altered personal appearance or as a consequence of chronic pain. Other painful musculoskeletal conditions may develop as the body compensates for the abnormal position of the head and neck, this may include back pain and mobility problems if the body has become twisted and contorted trying to compensate, problems are likely to be more severe if treatment has not been effective. Swallowing problems are sometimes associated with this condition.
The following terms may be used in medical evidence:
- Rotational torticollis: the head is turned to one side
- Simple torticollis: the head is not tilted; there may be increased tone of the neck muscles
- Laterocollis: head is tilted to one side – the ear is closer to the shoulder.
- Anterocollis: the head is bent forwards.
- Retrocollis: the head is bent back.
- Spasmodic jerks: the head is jerked into an abnormal position and recovers slowly towards normal.
- High-frequency oscillations: this described repeated nodding movements in any direction, may also be described as a tremor.
- Tremulous torticollis: there is major head tremor, which can vary in direction and severity.
Hemifacial spasm
This condition produces muscle spasms of the facial muscles which are very similar to dystonic spasms. It affects either the right or left half of the face only; it usually starts with twitches and spasms around the eye which spread to the lower face jaw and mouth on the same side. Eventually the whole of one side of the face may be affected by constant twitches. Vision may be very impaired on the affected side. Technically, it is not a dystonia as it is thought to be caused by irritation or compression of the facial nerve, sometimes by a blood vessel at the base of the brain; the most commonly used treatment is injection of Botulinum toxin. Surgical decompression of the facial nerve can be an effective treatment in severe cases. The muscle spasms have similar impact on quality of life as any other cranial dystonia.
Dystonic Writer’s cramp – focal hand dystonia
This condition affects the hand and forearm and is a form of dystonia; it is similar to the other dystonia conditions described in this guidance. This condition is not related to holding a pen awkwardly or too tightly nor is it the cramping and stiffness people without dystonia get when they write for a long time. In dystonia writer’s cramp the spasms and cramping come on rapidly on writing and can be very task specific. It does not usually respond to re-training and physical therapy. Tremor may be a significantly disabling feature in some cases.
This type of dystonia may have an effect on other activities carried out with the hand such as using a knife, putting on make-up etc. It is a type of task specific dystonia affecting the hand and forearm due to involuntary muscle spasms of the muscles in the forearm or hand during certain tasks. Other types of task specific dystonia include musician’s dystonia. This most often affects keyboard players (right hand) and string players (left hand) – i.e. the busiest hand when playing. It can also affect woodwind players and even the lips in brass instrument players. Other occupations that involve repetitive hand movements are also affected. In writer’s cramp the other hand can be used for writing but the condition may occur on that side too.
Generalised dystonias
Dystonias are movement disorders; the main symptom is prolonged muscles contractions causing abnormal postures of the body. Such movements cannot be consciously prevented or controlled. In some people there is an underlying cause for dystonia such as cerebral palsy. Conditions that cause dystonia include metabolic conditions such as Wilson’s disease and Kernicterus. These conditions often produce other symptoms and signs in addition to dystonia. In over 70% no cause can be found and this is termed ‘idiopathic torsion dystonia or ‘primary’ dystonia. These cases can have a genetic basis. Where the dystonia is caused by another condition this is called ‘secondary dystonia’.
Dystonia may be inherited, like other heritable conditions the genes responsible have variable effects on individuals. One individual may not be affected until middle age and develop a focal dystonia only. Another individual with the same genetic abnormality may be severely affected by generalised dystonia from childhood onwards.
Idiopathic Torsion dystonia (primary torsion dystonia)
This term covers any dystonia of unknown cause, including both focal and generalised dystonia. In practice the term tends to be used for generalised dystonia as the focal dystonias are known by their individual names. In this section the focus is on idiopathic dystonia that begins in childhood or early adulthood. In these cases the disease is more often generalised, progressive and severe. The condition may start as a focal dystonia of a limb for example and then progress to affect other parts of the body. In children the condition usually starts with Dystonic spasm in the legs when walking. Over some years it progresses to all areas of the body. Severe disability usually occurs within 5-10 years of onset. Severe disability in this context means that the dystonia affects the legs so severely that walking for more than a few yards is not possible and dystonia of the upper limbs may make self care impossible or at least very difficult. Very rarely the condition may resolve either temporarily or permanently within the first five years but this is unusual and cannot be predicted in an individual case. Intelligence is normal.
Dopa-responsive dystonia-parkinsonism (DRD/Segawa’s Syndrome)
This condition is hereditary and often presents in childhood. There are 2 types of this condition; the type depends on which enzyme deficiency is causing the disease. Severe type results in mental retardation, seizures and severe dystonia. In the more common form of DRD there is partial deficiency of the enzyme GTPcyclohydrolase 1 and intelligence is normal and dystonia mainly affects the legs making walking difficult. The dystonia gets worse during the day and is better after a period of sleep. This type responds well to drug treatment.
Rare dystonias
Myoclonus dystonia
Myoclonus refers to sudden involuntary ‘shock-like’ muscular contractions. These contractions usually affect the arms, shoulders, neck or trunk. The sudden movements are called ‘myoclonic jerks’. Onset is usually in childhood or adolescence; other dystonic movements may develop later in life. The frequency of jerks stabilises within a few years. They are not likely to be disabling but will preclude employment in certain jobs. The course of the disease is usually benign. If another dystonia has developed in addition to myoclonus review that section for disabling effects.
Tardive dystonia
This type of dystonia is a drug side effect and develops most commonly in younger people taking dopamine receptor blocking drugs for months or years. The condition can resolve if the causative drug is stopped at the onset of symptoms. The longer the drug is continued the more likely to dystonia will be permanent. The main symptoms are strong uncontrollable muscle spasms in the trunk, neck, arm and leg muscles. These may be painful and affect sleep.
Tardive dyskinesia
This type of movement disorder is a drug side effect and develops most commonly in older people taking dopamine receptor blocking drugs for months or years. The condition can resolve if the causative drug is stopped at the onset of symptoms. The longer the drug is continued the more likely the disorder will be permanent. The main symptoms are ‘fidgety’ rhythmic type movements of the facial muscles, grimacing and lip smacking. Movements may be constant, the condition is very disfiguring. Akathisia is medical term meaning ‘unable to keep still’; constant fidgeting is a typical symptom of the condition.
Amended May 2009
