Cervical dystonia, the most common form of focal dystonia, is characterized by abnormal squeezing and twisting muscle contractions in the head and neck area. Sustained muscle contractions result in abnormal positions or posturing. Almost all dystonic movements share a directional quality that is typically sustained. Movements may be prolonged or occur in an instant. In general, the dystonias may be classified based on: the age at which symptoms appear; the area or areas of the body that are affected (anatomical distribution); or the cause of the dystonia. CD is classified as a focal dystonia because it typically affects one area of the body (i.e., head and neck).
The dystonic muscle spasms associated with cervical dystonia (CD) may affect any combination of neck muscles. These sustained muscle contractions or spasms result in jerky head movements or periodic or sustained unnatural positioning the head (dystonic posturing). Sideways or lateral rotation of the head and twisting of the neck is likely the most common finding in CD. This is known as rotational cervical dystonia. In addition, tilting of the head is often present. The most common form of torticollis is characterized by turning, flexing, or extending of the neck to the side (laterocollis or lateral flexion). Less commonly, posturing to the front (anterocollis) or back (retrocollis) may also occur. One shoulder may be elevated and displaced forward on the side toward which the chin turns. In addition, there is often mild associated dystonia in the upper arm muscles on the same side (segmental dystonia). There does not seem to be an association between “handedness” and the direction of the tilt.
Muscle hypertrophy is present in almost all CD patients. Over two-thirds or up to 80% of patients, particularly those with sustained head deviation, have associated neck pain. About 33% to 40% of these patients also experience head tremor (i.e., dystonic tremor), hand tremor, or both. Approximately 20% of patients with CD also have blepharospasm or dystonia in other muscles or in muscle groups of the arm or hand. In addition, about 15% of patients have hand tremor resembling essential tremor.
Evidence suggests that about 10% to 20% of patients with cervical dystonia may have brief, spontaneous remissions (Poewe W, 1992). Almost all affected individuals eventually experience a relapse of symptoms. An additional 10%, particularly patients with an earlier age at symptom onset, may have longer remissions of about two to three years, typically beginning during the first few years following disease onset.
In most cases, the exact cause of CD is usually not known. The condition appears sporadically, in the absence of a documented family history of the disease. In about 10% to 15% of cases, more than one family member may be affected. Several families have been described with autosomal dominant, adult-onset, primary dystonia that is focal in distribution, affecting the neck region. This form of the condition has been called “familial torticollis.” In one German kindred, the autosomal dominant disorder was mapped to chromosome 18p. This genetic location or locus has been designated as DYT7. However, other kindreds with familial torticollis have been excluded from the DYT7 as well as the DYT1 regions and the responsible gene location has not yet been identified.
Some studies also suggest that focal dystonia may be precipitated by trauma or overuse of the affected region of the body. For example, some researchers theorize that prior trauma may play some role in triggering disease onset in patients who carry a mutated DYT1 gene for DYT1 dystonia. In addition, several studies have suggested a possible association of focal dystonias with prior peripheral trauma. For example, researchers have reported that trauma occurred three to six months prior to symptom onset in approximately 5% to 12% of patients with cervical dystonia.
In some cases, the relationship between trauma and the onset of dystonia is clear when dystonia follows brain injury or severe peripheral trauma. However, in many patients, the relationship is less clear and trauma alone probably would not be sufficient for the development of dystonia. Rather, some research suggests that trauma may play some role in triggering dystonia in those with previously, very mild, undetectable cases-or in patients with an existing, potentially genetic, susceptibility to the disorder. Further research is necessary to determine the various underlying genetic, environmental, or other underlying mechanisms that may play a role in causing the focal dystonias, including cervical dystonia.
Botulinum Toxin has shown to be effective in the treatment of all forms of cervical dystonia. This toxin is FDA approved for mild, moderate, and severe dystonia.
DYSTONIA CASE STUDIES
CASE STUDY: PATIENT EK
“About two weeks after my treatment I woke up on a Sunday morning and I sat on the side of the bed. And then I realized the pulling to the left had stopped all together. I remember calling people and telling them that we’ve killed the monster”
CASE STUDY: PATIENT DM
“The life altering thing has been that it has really given me a lot of hope as far as being more functional, not so embarrassed to go out in public because of the head turning”
CASE STUDY: PATIENT GM
“About the tenth day, I woke up and it was just amazing all of a sudden my head was back where it is right now. And it didn’t have the pulling or most of the pain…and the spasm was gone”.
*Individual results may vary