Contacts:

Contacts:
Sarah Goodwin

Kathi Ovnic
Holly Korschun
October 13, 1998

DYSTONIA AT EMORY: Writer's Cramp, Precious Poison, Surgical Pallidotomy, Deep Brain Stimulation and Genetic Tests


Raising awareness for the little known yet fairly common movement disorder known as dystonia is the intent of DYSTONIA AWARENESS WEEK, Oct. 11-17, spearheaded by the Dystonia Medical Research Foundation and supported by neurologists at the Emory University School of Medicine, among others.

"Increasing awareness of dystonia is important for a number of reasons," says dystonia specialist Marian L. Evatt, M.D., assistant professor of Neurology at Emory. "Primarily, we want to make sure persons with this disorder are being correctly diagnosed so that they may receive appropriate treatment. Secondly, we hope to reduce the stigma experienced by many patients because of their symptoms. Finally, we hope increased awareness will bring improved support for further research into better treatments ­ and perhaps a cure."

Physician-scientists in the Movement Disorders Program of Emory's Department of Neurology lead one of the region's most active centers for treating and studying dystonia. Patients from across the United States and abroad are evaluated at Emory each year for various forms of this disabling disorder and many receive access to the latest experimental drug and surgical treatments. Emory neurologists, eye surgeons and ear, nose and throat specialists run a well-established program in injecting a potent neurotoxin into affected areas to temporarily but significantly relieve symptoms ­ and they currently are pioneering surgical treatments with potential to permanently improve symptoms.

Dystonia causes muscles to pull or spasm. Effects may be localized to particular regions such as the neck and shoulders, vocal cords, eyelids, arms or legs, or they may be more generalized. Writer's cramp is one of the better known forms. Because its effects are so varied and because symptoms may mimic other conditions, dystonia is difficult to diagnose, Dr. Evatt says. Cervical dystonia of the neck is often misdiagnosed as pinched nerve, for instance, and many forms of the disorder are wrongly attributed to stress.

"Stress reducing treatments along won't relieve the abnormalities within the basal ganglia -- the brain region responsible for controlling movement," Dr. Evatt says. "Nor will it correct the recently identified genetic flaws in the DYT1 gene associated with early onset torsion dystonia. But accurate diagnosis and a careful treatment plan can dramatically improve quality of life."

DEEP-BRAIN STIMULATION

Two patients at Emory are also among the first in the world to receive deep-brain stimulation for dystonia. Approved by the Food & Drug Administration for tremor and epilepsy, the treatment involves the neurosurgical implantation of a pacemaker-type device in the neck that delivers controlled electrical stimulation to brain regions associated with dystonia, particularly the pallidum.

Potential advantages of this unproven yet promising procedure involve saving cells from ablation. Physicians retain the flexibility to end or reverse treatment, or adjust stimulation frequencies.

PALLIDOTOMY, ETC.

Initial outcomes look good in the first few dystonia patients to undergo another genre of surgery for the disorder, though doctors are quick to point out that long-term results are yet to come. During the surgery, neurologists use a microelectrode brain mapping procedure -- pioneered by an Emory research team originally for Parkinson's disease ­ to identify those few brain cells associated with dystonia to be ablated by neurosurgeons.

In pallidotomy, Dr. DeLong and Emory neurology colleague Jerrold Vitek, M.D., Ph.D., are guided by the electrical charges of single nerve cells as they pinpoint for Emory neurosurgeon Roy A.E. Bakay, M.D., the troublesome cells in the pallidum. During thalamotomy, the team targets cells within the brain's thalamus. Thus far at Emory, 12 dystonia patients have undergone pallidotomy and two dystonia patients have undergone thalamotomy as part of clinical trials.

GENETIC TESTING

In 1995, a gene associated with the dopa-responsive form of dystonia was located on chromosome 14, and in 1997, the gene responsible for most inherited childhood onset dystonias, DYT1, was identified on chromosome 9. Persons with dystonia or who have a family history of the disorder may undergo genetic testing for the DYT1 gene. Genetic counselors and physicians at the Medical Genetics Section of The Emory Clinic are available to help arrange genetic consultations and testing for persons who suspect they may have the gene, and they can help patients determine their probability of passing along the gene.

PRECIOUS POISON

The biological warfare agent and deadly neurotoxin that causes food poisoning "offers significant pain relief for some dystonia patients and may restore function for others," Dr. Evatt says. Marketed by Allergan as botulinum toxin type A (Botox®), injections of minute amounts of the toxin have given thousands of patients reprieve from disabling symptoms.

"Botulinum toxin, a complex protein produced by the bacterium Clostridium botulinum, weakens a muscle sufficiently to reduce a spasm but not enough to cause paralysis," according to Dystonia Medical Research Foundation literature. "It is a nerve 'blocker,' binding to nerve endings and preventing the release of chemical transmitters that activate muscles. The chemicals carry the "message" from the brain that causes a muscle to contract. If the message is blocked, the muscle doesn't spasm."

Dr. Evatt and her neurology colleague Alan Freeman, M.D., administer Botox to dystonia patients with involuntary limb movements, abnormal head turning and other generalized forms of the disorder. Emory eye surgeon Ted Wojno, M.D., opens the eyes of functionally blind patients, and Emory ear, nose and throat specialist William Grist, M.D., gives patients with spasmodic dysphonia their voice back.

Beneficial effects of the toxin wear out usually within a few months, requiring patients to be re-injected a few times a year. Benefits may subside after several injections as resistance grows.

The amount of the toxin required for Botox formulations is so infinitesimal that until a few years ago, the company's entire raw stock took up the space of a two-liter soda bottle. And that single batch of toxin-producing bacterium was begun and maintained for some 20 years. Botox is now created in a continuous process as an advanced type A bulk toxin.

WRITER'S CRAMP

Slang term for a crippling problem writer's cramp is much more than a temporary cramp. Persons affected by this type of focal dystonia may be unable to grasp a pen with which to write or a fork with which to eat, making even the most basic activities of daily living difficult or impossible. It commonly is misdiagnosed as carpal tunnel syndrome, tennis elbow, arthritis, strain or stress.

Writer's cramp is triggered when the hand is used to perform fine motor skills such as writing or playing a musical instrument. In fact, it is the most common of the action-induced or task-specific dystonias known as occupational dystonias.

"Some people notice that the hand (while writing) freezes during an attempt to move across the page and describe the hand as having a 'mind of its own.' As soon as the writing instrument is removed from the hand, the muscles relax," according to literature from the Dystonia Medical Research Foundation. "The symptoms usually begin between the ages of 30 and 50 years old and affect both men and women Cramping or aching of the hand is not common. Discomfort may occasionally be present in the fingers, wrist or forearm, but it is usually mild."

Motor skills are improved in some patients by techniques as simple as using larger writing instruments or learning to writing with the unaffected hand, or may require injections of a neurotoxin nerve blocker every few months. Physical and occupational therapy are often important adjuncts.

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(Note to Editors/Producers: A number of patients with fascinating stories to tell are available for interviews. Patients represent the various forms of the disorder and the treatments highlighted above. Doctors, of course, are available, too. Call Sarah Goodwin in Emory Health Sciences Communications at 404/727-3366.)

For more general information on The Robert W. Woodruff Health Sciences Center, call Health Sciences Communication's Office at 404-727-5686, or send e-mail to hsnews@emory.edu.


Copyright ©Emory University, 1998. All Rights Reserved.