Dystonia is neurological involuntary movement disorder, in which a muscle (focal dystonia) or group of muscles contract (segmental dystonia), causing twisting body motions, tremors and repetitive abnormal postures or movements. Sometimes this disorder causes pain and affects any part of the body including the arms, trunk, neck, eyelids, face and vocal cards. In 1911, Herman Oppenheim, Berlin neurologist first discovered this disorder, and related symptoms. Those diagnosed with dystonia usually have normal intelligence and not associated to psychiatric disorders. It is the third most common movement disorder after Parkinson Disease and Tremor, affecting more than 300,000 people in North America (According to the Dystonia Medical Research Foundation.), and all races and ethnic groups. Ashkenazi Jews have a high prevalence of the disorder, around 1 in 10,000, due to a mutation, called founder mutation, has been passed down from the original carrier of the gene to subsequent generations. In some cases, the symptoms of this disorder, related to side affects, when taking medication and resulting from a specific form of lung cancer. Sometimes, writer’s cramp (task specific), typist’s cramp, and pianist’s cramp, musician’s cramp, and golfer’s cramp is associated to symptoms of dystonia. Dystonia or idiopathic is commonly related to a genetic mutation (Torsion dystonia or hereditary dystonia), which symptoms are first observed in childhood around the age of twelve. Characterized by involuntary movement, usually starting in the arms or legs, and eventually affects the rest of the body, within about five years. The disorder is not fatal, however can be severely depilating. By the time, these children reach adulthood confinement is to a wheelchair, because of lack of performing simple motor tasks.
The classifications of dystonia, according to the parts of the body affected: Most common type dystonia is Spasmodic Torticollis (cervical dystonia). Symptoms include intermittent spasms of the neck muscles, causing involuntary rotation and tilting of the head. Frequently these movements are painful. This disorder affects the muscles of the larynx, causing the voice to sound broken or reducing it to a whisper. In most cases, individuals first experience symptoms in middle age. This disorder has three different varieties, causing sustained turning of the head to one side, clonic, causing shaking movements of the head, and mixed tonic and clonic: Includes both kinds of movements. Approximately, ten to twenty percent of those with Spasmodic Toricollis experience a spontaneous remission, however may not be lasting. Second common type of dystonia is Blepharospasm: Symptoms are involuntary forcible closure of the eyelids, which starts with uncontrollable blinking. Frequently, only one eye is affected but eventually both eyes are usually involved. Despite having good vision, spasms may lead to eyelids completely closed causing functional blindness. Oromandibular dystonia affects the muscles of the jaw, lips, and tongue. Characterized by the jaw pulled either open or shut, and speech and swallowing made difficult. Cranial dystonia describes the affect of muscles of the head, face and neck. Oromandibular dystonia affects the muscles of the jaw and tongue, causing distortions of the mouth and tongue. Meige’s syndrome is a combination of blepharospan and oromandibular dystonia. Sometimes causing a spasmodic dysphonia.
Published in September 1997, issue of Nature Genetics, a study supported the National Institute of Neurological Disorders and Stroke (NINDS), located in Bethesda, Maryland (Leading supporter of research on the brain and nervous system) discovered a gene responsible for early onset torsion dystonia. Discover of the gene, will make early diagnosis of this disease easier and investigate the factors that might contribute to dystonia. Inheriting a copy of a muted dystonia gene is dominant over a copy of normal inherited gene. Thirty to forty percent of people, who have a mutated gene, develop symptoms referred to as “penetrance”. Pediatric neurologist Giovanna Spinella M.D. at the NINDS, said: “We know that people carrying the mutated gene are vulnerable only within a certain age range, between the ages of 5 to 28. Once gene carriers pass this age range, it’s very unlikely that they will develop the disorder. This means there must be some environmental or biological factors influencing the expression of the gene around the time of life.”
Treatment options for dystonia include anticholinergic medications, such as trihexyphenidyl and benztropine. These medications are often significantly effective, however cause dose dependency side effects of sedation, dry mouth, and reduced short-term memory. Benzodiazepines effective to reduce dystonic muscle spasms however may cause sedation, and cognitive side effects. Effective treatment for focal and segmental dystonia: Administering intramuscularly injections of chemodenervation and botulinum toxin type A and Type B. The medication provides improvement of abnormal postures. In conjunction with available medication treatments, physical therapy including well fitted, braces may be helpful some dystonic patients.
A study published in the November 9, 2006, issue of The New England Journal of Medicine, confirmed preliminary evidence regarding a new developed surgical treatment: Deep brain stimulation has provided dramatic benefits for dystonia patients, compared to other treatment options. The surgical treatment relieved symptoms associated to painful involuntary postures. Researchers at ten medical centers in Germany, Norway and Austria, implanted electrodes into the brains of forty patients with dystonia, but only half of number, actually received an implanted neurostimulation. After the study, all dystonia patients received the same stimulated implant. The Medtronic Implantable neurostimulation system – consisting of a device similar to a cardiac pacemaker, connected with extensions to two thin insulated wires called leads, inserted into the brain (one on each side). Electrical impulses are precisely targeted to the areas of the brain involved in motor control. According to Dr. Kathryn Halloway, head researcher: “The study shows that many forms of dystonia did respond well to the new treatment.” Improved motor score reached 46 percent. Also, surgery is more effective if performed earlier in the course of the disease, and equally effective, treating patients with long-standing symptoms. Side effects noted during the study included infections at the stimulator site, accumulation of body fluids near the surgical site or lead breakage and twelve percent experienced, speech problems after the surgery. The United States Food and Drug Administration approved Medtronic deep brain stimulation therapy for treating various classifications of dystonia, in patients seven years of age and older.
