Dystonia is an involuntary change in muscle movement during a voluntary activity or in the maintenance of posture; it causes twisting and repetitive movements, abnormal postures, or both. It is commonly triggered or increased by an attempted voluntary movement. Dystonia may be limited to a single body part (e.g. arm) or can be generalized. It may be present at rest or with a posture (e.g. sitting), but it can be triggered or worsened by attention, distraction, startle, overuse, fatigue, touch or pain. Muscle spasticity can be, but is not always present.

In simple terms, dystonia is often characterized by an abnormal posture or position or an uncalled for positioning of a body part such as an arm, body trunk or whole body; it is brought on during voluntary movement (e.g. lifting the arm) or when maintaining a posture (e.g. sitting). It can be present in children and in adults with cerebral palsy. It is different from but can co-exist with muscle spasticity. Persons with cerebral palsy can have muscle spasticity, dystonia or both.

The treatment of generalized dystonia begins with oral medications; but these are often unsatisfactory. Several oral medications are available but when given in tolerable doses, they are effective in only some persons. If given in high doses, there are often unsatisfactory side effects. Thus, the use of a powerful oral drug, Baclofen, has been considered for use by direct injection into the spinal fluid. This use permits smaller doses to be administered which have a direct effect on the central nervous system without the many side effects of taking the medicine by mouth.

This therapy for dystonia administered into the spinal fluid has already been demonstrated to be useful in the treatment of spasticity.

Dr. A. Leland Albright and his colleagues at the Children’s Hospital of Pittsburgh reported on a trial to evaluate the use of Baclofen administered intrathecal (into the cerebral spinal fluid) for persons with severe generalized dystonia. 71% had cerebral palsy. The patient’s ages ranged from 3 to 42 years; the average age was 14. Baclofen was administered continuously by means of an implanted pump in 72% of patients or by a single injection into the spinal fluid in 18% of patients. As a result of either therapy, the degree of dystonia decreased significantly over a 24 month period. Patient questionnaires reported that quality of life and ease of care improved in 86%; speech improved in 33%; swallowing in 26%; upper limb function improved in 34%; lower extremity function improved in 37%.

There were some minimal side-effects of therapy in patients: constipation (19%); decreased neck/trunk control 8%; drowsiness (6%). Surgical complications due to the implanted pump and tube to the spinal canal occurred in 38%; these were usually easily managed.

Comment:

Dystonia is a very important functional problem in children and adults with cerebral palsy, often limiting quality of life significantly. The first treatment is usually an oral medication; this is sometimes successful. However, in those persons who have undesirable side effects usually due to the high doses that may be required for a reasonably good result, the use of intrathecal Baclofen now needs to be considered. This procedures requires an expert team who have the skills and experience necessary for this intervention in order to promise a good result and provide for patient safety.

A carefully controlled clinical trial provides the information necessary so that the results can be included under the term “evidence based medicine”. However, all clinical trials do not have to include randomization (patients assigned by chance to the treatment group or to another group). Although randomization is the “gold” standard for clinical trials, the patient can serve as his/her own control when the natural history of the disorder is well known, inclusion and exclusion criteria established and meaningful outcomes measures utilized. This method was used successfully by Dr. Albright in evaluating the use of intrathecal Baclofen in the treatment of dystonia.

¹ Albright A..L. et al. Intrathecal Baclofen for Generalized Dystonia. DMCN (2001) 43: 652-657