The importance of diagnostic subtype
The dystonias may be categorized by body region affected, age at onset, and etiology. Each of these categories has important implications for treatment, and accurate diagnosis is important because different forms of dystonia may respond best to different treatments. Most importantly, there are some special populations with highly effective treatments that target underling mechanisms rather than symptoms, as described below. [7, 8]
Age at onset is important because childhood-onset dystonias are more likely to begin in a limb and progress to generalized involvement. In contrast, adult-onset dystonias are more likely to begin in the craniofacial region or neck with limited spread. Children are more likely to have a discoverable inherited etiology, while the majority of adult cases are idiopathic. In children, the increased risk for progression to generalized dystonia and higher likelihood of finding a cause mandates more extensive diagnostic testing. For children and young adults where dystonia seems to be an isolated problem, genetic testing for DYT1 or DYT6 dystonia merits consideration, especially if there is a family history.
For children and young adults where dystonia is not an isolated feature, such as in the dystonia-plus syndromes and hereditary or degenerative dystonias, there is an enormous list of potential disorders for diagnostic testing. It is not feasible to test for all potential disorders where dystonia may occur. Instead, the clinical evaluation is helpful for guiding a more selective approach to testing. Consultation with specialists in early-onset dystonias or neurogenetics can be invaluable. Tests for disorders where specific treatments are available are an essential part of the treatment strategy and are outlined below.
The Role of Counseling
Counseling is a critically important pre-requisite for successful treatment for several reasons:
First, patients with dystonia may go for several years without a correct diagnosis, and they frequently are offered many ineffective treatments during this time. Many are told their problem is psychological. As a result, patients often arrive to clinic with a sense of frustration that providers do not understand their problem or how to treat it. Helping them find proper sources of information and support is an invaluable part of the treatment strategy.
- Second, dystonia is a chronic disorder for which a cure does not yet exist. Many useful treatments are available, but an empiric approach is often necessary to find the best solutions with the fewest side effects. Inherent in the empiric approach is the time required to work through some therapies that ultimately do not prove useful.
Third, most available treatments require weeks or months to reach peak benefits. Oral medications must be titrated over several weeks, BTX treatments may yield better outcomes over several treatment sessions as target muscles and doses are customized for optimal effect, and optimal benefits from DBS may take 3-12 months. Education is essential to ensure that expectations for treatment are realistic in terms of the magnitude of benefit and the time required to reach the benefits.
Education and counseling of patients is aided by a number of very useful resources. Several patient advocacy groups provide information through internet sites, short educational brochures, and local support groups. A list of these patient advocacy groups can be found at:
The Global Dystonia Patient Registry allows patients to sign up to be kept informed of novel research findings and opportunities for participating in research ( http://www.globaldystoniaregistry.org/).
Finally, the Dystonia Coalition is a collaboration between multiple academic center and patient advocacy groups that is funded by the NIH to advance clinical and translational research in dystonia. Patients may explore opportunities for participating in research at (www.rdcrn.org/cms/dystonia/studies).
H. A. Jinnah, MD PhD
Emory University School of Medicine
Atlanta, GA 30307