The muscle contractions, abnormal postures, spasticity, rigidity and repetitive movements that are so common in HSS patients are part of a syndrome called dystonia.

Because dystonia is a syndrome - a collection of disorders rather than a single disease - the same treatment won’t work in every individual, Dr. Mark Hallett, clinical director of the National Institute of Neurological Disorders and Stroke at NIH, told families at the First International HSSA Family Conference. He said successful treatments often are arrived at by trial and error, and outlined three basic kinds of treatment.

The first, systemic therapy, involves the use of various drugs to try and control symptoms. "If a drug works, increase it slowly until side effects develop," Hallett advised. Some commonly used drug therapies include:

* Benzodiazepines, a class of drugs that interfere with chemical activities in the nervous system and brain. These drugs reduce communications between nerve cells. Consequently, such medications may relax muscles and ease symptoms associated with dystonia. Diazepam (Valium) and clonazepam (Klonopin) are two types of benzodiazepines that are most commonly used to treat dystonia.

* Baclofen (Lioresal) is used to treat individuals with spasticity. Baclofen acts primarily on the spinal cord to reduce the release of neurotransmitters that stimulate muscle activity. Baclofen has been used to treat both primary and secondary dystonias as is the case with HSS patients. This drug may be administered orally or via a surgically implanted pump that delivers the drug directly to the spinal cord (intrathecal baclofen).

* Anticholinergics, which block the action of the neurotransmitter acetylcholine, thereby deactivating muscle contractions. Trihexyphenidyl (Artane) and diphenhydramine (Benadryl) are the most commonly used anticholinergics for dystonia.

* Dopamine-blocking or dopamine-depleting agents may also be used to treat some patients with dystonia.

Secondly, local therapy is available which works on one particular area. One option is botulinum toxin which when used in small doses is considered very safe. It paralyzes the muscles, but the effects are temporary, lasting approximately three months. Other choices are a myectomy where a portion of an overactive muscle is removed, and a neurectomy which destroys the nerve.

The third and most radical treatment option is neurosurgery. The choices include pallidotomy, thalamotomy, and deep brain stimulation. During the first two surgeries, specific areas deep within the brain that control movement are targeted for destruction. In deep brain stimulation, electrodes are implanted in a specific area of the brain and a device is placed under the skin in the area of the collarbone. The device sends signals via the implanted electrodes, to help "rebalance" the control messages in the movement control centers of the brain. These treatments are used as a last resort, when all others have failed.