Cervical Dystonia

Cervical Dystonia

What is it?
Cervical Dystonia, also known as spasmodic torticollis, is a focal dystonia characterised by neck muscles contracting involuntarily, causing abnormal movements and awkward posture of the head and neck.

The terms  used to generally describe the position of the neck: forward (anterocollis), backwards (retrocollis), and sideways (torticollis). The movements may be sustained or jerky. Spasms in the muscles can result in considerable pain and discomfort.

Terms used to describe cervical dystonia include: spasmodic torticollis, torticollis, adult onset focal dystonia.

 

Symptoms
In cervical dystonia, the neck muscles contract involuntarily in various combinations. Sustained contractions cause abnormal posture of the head and neck, while periodic spasms produce jerky head movements. The severity of cervical dystonia  may vary from mild to severe.

Cervical dystonia may begin in the neck and spread into the shoulders, but the symptoms usually reaches a plateau and remains stable within five years of onset. This form of focal dystonia is unlikely to spread beyond the neck and shoulders or become generalised dystonia. Occasionally, there may be an associated focal dystonia.

 

Cause
Cervical Dystonia is believed to be due to abnormal functioning of the basal ganglia, which are deep brain structures involved with the control of movement. The basal ganglia assist in initiating and regulating movement. What goes wrong in the basal ganglia is still unknown. An imbalance of dopamine, a neurotransmitter in the basal ganglia, may underlie several different forms of dystonia, but much more research needs to be done for a better understanding of the brain mechanisms involved with dystonia.

Cervical dystonia maybe primary (meaning that it is the only apparent neurological disorder, with or without a family history) or be brought about by secondary causes such as a physical trauma. Cases of inherited cervical dystonia have been reported, usually in conjunction with early-onset generalised dystonia, which is associated with the DYT gene.

 

Diagnosis
Diagnosis of cervical dystonia is based on information from the affected individual and the physical and neurological examination. At this time, there is no test to confirm diagnosis of cervical dystonia, and, in most cases, laboratory tests are normal.

 

Cervical dystonia should not be confused with other conditions which cause a twisted neck such as local orthopedic, congenital problems of the neck or ophthalmologic conditions where the head tilts to compensate for double vision. It is sometimes misdiagnosed as stiff neck, arthritis, or wry neck.

 

Treatment
Currently there is no cure for dystonia, but treatments are available to help to ease the symptoms related to the disorder including spasms, pain, and disturbed postures. Working with your doctor, an individualized strategy for treatment can be developed.

 

The approach for treatment of dystonia is usually three-tiered: oral medications, botulinum toxin injections, and surgery. These therapies may be used alone or in combination. Complementary care may also have a role in the treatment depending on the form of dystonia, and supportive therapy may provide an important adjunct to medical treatment.

 

Medications
A multitude of drugs have been studied to determine benefit for people with cervical dystonia and have demonstrated some benefit.

The categories of drugs reported to help relieve the symptoms associated with cervical dystonia include anticholinergic drugs Artane (benzhexol), Cogentin (benztropine); dopaminergic drugs Sinemet or Madopar (levodopa), Parlodel (bromocriptine), Symmetrel (amantadine); GABAergic drugs Valium (diazepam).

 

Botulinum Toxin Injections
Botulinum toxin injections are the primary and most effective form of treatment for cervical dystonia. It is a therapeutic muscle-relaxing agent that helps reduce the uncontrollable muscular contractions associated with dystonia. It is injected into specific muscles where it acts to weaken muscle activity sufficiently to reduce a spasm but not enough to cause paralysis.

The three forms of botulinum toxin that are approved for the treatment of cervical dystonia are BOTOX and DYSPORT (botulinum toxin type A) and NEUROBLOC (botulinum toxin type B).

A crucial element to successful botulinum toxin injections is that the appropriate muscles are injected. For this reason it is important that the physician administering the injections is experienced with botulinum toxin injections and is very knowledgeable about the anatomy of the neck and surrounding areas. The muscular structure of the neck is very complicated, and  must also be aware of anatomical variation.

It may be necessary to inject different muscles at some visits. Extensive EMG tests may be helpful, as is listening to the affected person.

Although the overall effect of these botulinum toxins are similar, the specific mechanism by which toxin achieves this effect differs along with its preparation and dosage.

The side effects from botulinum toxin treatment include temporary problems with swallowing (dysphagia), too much weakness in the muscles injected, and spread to other muscles. Some people have reported a flu-like syndrome following treatment, and temporary pain following injection. These side effects are possible following injection of either serotype. Up to one third of patients may experience one or more of these side effects. Typically, they are mild and transient. NEUROBLOC additionally has been observed to cause a transient dry mouth.

 

The clinical differences between the serotypes of botulinum toxin are due to the unique protein structure of each although there are some areas of overlap. An important result of these differences is in the specific “neutralizing” antibodies that may be formed following repeated injections. An antibody is the response of the body to a foreign substance and antibodies are responsible for immunity. The developments of “neutralizing” antibodies are linked to a lack of response to injection of that serotype. This would cause a patient who had done well with injections to become “immune” and lose the benefit they previously experienced.

The factors that may increase the risk of immunity include large doses of the toxin, frequent injections at less than three-month intervals, and the specific properties of the commercial preparation used. There may also be a genetic susceptibility that predisposes certain people to develop immunity. In people who have lost sensitivity to one serotype, injection of the other serotype may be effective. Because it is not clear exactly how immunity develops, it seems prudent to use only one serotype at a time and not to mix or alternate the two.

There are other reasons why a person may experience a loss of benefit after having experienced a previous good response. Some patients may have a change in the muscle activation pattern, requiring adjustment of the muscles to be injected. Sometimes deep muscles become involved and may be missed during an injection. Hence, in a patient who reports a loss of benefit following injection, an evaluation by the physician for both immunity and other factors should be undertaken.

 

Surgery
Surgery may be considered when patients are no longer receptive to other treatments, including botulinum toxin injections and medications.

Selective denervation surgery is an option for some cervical dystonia patients,  and deep brain stimulation surgery is beginning to be explored for cervical dystonia as well.

Along with the type of torticollis a patient has, other factors influence the success of an operation. Every patient is unique and the muscles involved may vary from one patient to another. It is for this reason that the preoperative evaluation is important so that the patient’s head and neck movements and the muscular contractions causing it are identified and characterised.  Also, surgery should only be considered when done by a neurosurgeon who has significant experience with these specific operations.

 

Complementary Therapy
Physiotherapy may be helpful in the treatment of cervical dystonia. The goals of physiotherapy for people with cervical dystonia are to help increase range of motion, to increase flexibility, to correct muscle imbalances, to improve posture, to increase balance, to enhance functional abilities in home and workplace, and to improve coordination. More is not better in physiotherapy for people with dystonia, and “no pain, no gain” does not apply. Also, it is important to find a physiotherapist who is experienced with dystonia.

The use of a soft cervical collar is rarely helpful.

The use of sensory tricks (also known as geste antagoniste) may also be effective in dealing with cervical dystonia, such as gently touching the chin, other areas of the face or back of the head. Different sensory tricks work for different people, and if a person finds a sensory trick that works, it usually continues to work.

Neck manipulation by a chiropractor who is not very familiar with dystonia may aggravate the condition. Traction, also, is not a good idea. Gentle massage, however, can sometimes provide temporary relief. If it feels good, do it.

 

Support
Dystonia and its emotional offshoots affect every aspect of a person’s life – how we think, the way we act, and how we cope. By educating yourself with information, you have taken the first step in dealing with dystonia.

Stress is an inevitable part of life, and although it clearly does not cause dystonia, it can aggravate dystonia symptoms. Stress-reduction programmes such as relaxation techniques, meditation, and journal writing may be beneficial.

Sometimes depression can be a byproduct of dystonia. Depression may aggravate symptoms and make them worse, but, often, treating depression can result in an improvement of dystonia.  It is important to remember that depression is a disorder; it is treatable and not a reflection of one’s self.

Many people are experiencing similar symptoms. Reassurance from family, friends, and others who have dystonia is beneficial.  Sharing experiences at support group meetings offers encouragement, camaraderie, and the latest information about new treatments and medical advances.

 

Dystonia Ireland gratefully acknowledges  the Dystonia Medical Research Foundation for use of this information.