Cervical Dystonia

A Neurological Condition in Many Different Forms

What is dystonia?

Dystonia is a neurological condition that exists in many different forms. It is one of a collection of diseases known as movement disorders. It is a chronic condition and occurs when the brain activates muscles to pull in different directions. This can cause abnormal posture, slowness or incoordination of movement, tremor, spasm and/or muscle pain. Abnormal postures may be maintained for a long period of time (tonic) or happen from time to time (clonic).

Dystonia may affect one muscle or a group of muscles (focal dystonia), such as blepharospasm or cervical dystonia; two or three neighbouring muscle groups (segmental dystonia); the muscles of one side of the body (hemidystonia); or the whole body (generalised dystonia).

Some forms of dystonia are painful. Symptoms are exaggerated by fatigue, stress and emotional upset. In general, the condition improves with relaxation and sleep.

What is the cause of dystonia?

Research indicates that dystonia is likely to be related to some malfunction of a small but important area of the brain called the basal ganglia. This area plays a vital part in the coordination of muscle movement and assists in the fine-tuning required for voluntary movements such as riding a bike or walking. It is thought that the fault probably lies with chemical messengers – called neurotransmitters – in the basal ganglia that influence muscle movement in all areas of the body.

Primary dystonia refers to the lack of identifiable or suspected cause. The term secondary dystonia describes a condition in which the dystonia is thought to have a cause, such as stroke, trauma, a neurological disorder such as Parkinson’s disease, infections or other diseases involving the brain. Dystonia can also occur in association with the use of certain medications such as some psychiatric and anti-nausea medications.

The exact cause of dystonia is unknown but research has shown that genetics is a factor in certain types of dystonia, particularly generalised dystonia. Many studies have found that focal dystonias occur in families and recent research has identified a gene that is responsible for some childhood dystonias. Medical research into the possible hereditary nature of dystonia continues.

What is cervical dystonia?

Cervical dystonia, also known as spasmodic torticollis, is one of the focal dystonias.

People with cervical dystonia experience involuntary contractions of the neck (cervical) and/or shoulder muscles, which can lead to an abnormal positioning of the head and/or shoulders. Neck muscles may also contract repetitively, producing uncontrollable head movements.

Although cervical dystonia may develop at any age, it typically occurs in adults between the ages of 30 and 70 years old. Women are almost twice as likely to be affected with cervical dystonia as men.

Cervical dystonia affects 9 out of every 100,000 individuals, although this may be a conservative estimate since many remain undiagnosed if pain is the only major symptom and posture abnormality is mild. Due to a lack of available information, even in the medical profession, there is difficulty and delay in diagnosis.

The degree of disability can vary widely. Some people with cervical dystonia will have mild symptoms while others suffer a high degree of disability. Similarly some patients may have a fluctuation in symptom severity.

As with many medical conditions, there is no known cure. However, the condition tends to stabilise around 5 years after onset and there are effective treatments available.

Common forms of cervical dystonia:

Torticollis

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Anterocollis

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Laterocollis

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Retrocollis

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What are the symptoms of cervical dystonia?

The most obvious clinical sign in patients with cervical dystonia is an abnormal head position. The movement abnormalities and pain associated with cervical dystonia can be disabling. As the muscles of the neck are overactive, the patient’s posture may be affected causing pain and stiffness in other muscles not directly affected by the dystonia itself.

There are many different degrees of disability. Where some people with cervical dystonia have mild symptoms, others may suffer a high degree of disability. Similarly some people have fewer symptoms in the morning, particularly in the early stages of the disease, with symptoms returning as the day goes on. These people function better early in the day.

Diagnosing cervical dystonia

Although quite common, cervical dystonia can be misdiagnosed. People are told that they have a stiff neck, a ‘wry neck’, arthritis, or in some cases, Parkinson’s disease. Others are told that they have a stress disorder, and it is sometimes assumed that the condition is psychiatric in origin. This is because people with cervical dystonia can suffer from anxiety and depression. However cervical dystonia is a physical, not a psychiatric condition.

Diagnosis is based on doctors’ clinical judgement and they may be unable to give a clear diagnosis, especially when signs and symptoms are intermittent. No X-ray, blood test or diagnostic examination is available to assist in making the diagnosis and there is no recognised consistent or specific change in brain tissue or function that could help. Some tests and X-rays may be ordered to rule out other diagnoses.

Sometimes the head and shoulder movement occurs while walking or using both hands (e.g. driving a car, washing dishes).

What is the long-term outlook?

Cervical dystonia is not a life-threatening illness and it does not interfere with intellectual functions. However, it can cause physical, emotional and social problems due to pain, physical limitations and embarrassment.

There is currently no cure for cervical dystonia but different treatment options are available to alleviate the symptoms. Response to these treatments varies from person to person.

Cervical dystonia usually stabilises within 5 years, after which the symptoms remain much the same. In the majority of people the symptoms remain in the neck area.

About 10% of patients will go into remission, where the symptoms disappear or are considerably less for a short or a long period of time. Remission is more likely to occur early in the course of the disease.