Dystonia


Dystonia

Description, Causes and Risk Factors:

Abbreviation: DYT.

Dystonia is a movement disorder characterized by sustained involuntary muscle contractions causing twisting movements and abnormal postures. It may affect any body part including the arms and legs, trunk, neck, head, or face. It is the third most common movement disorder after Parkinson's disease and tremor, affecting more than 300,000 people in North America. It is a condition that knows no age, ethnic, or racial boundaries - it can affect young children to older adults of all races and ethnicities.

Dystonia

Classifications:

    Focal Dystonia - affecting a single body part or location.

  • Segmental Dystonia - affecting adjacent body parts.

  • Hemidystonia - affecting one side of the body.

  • Generalized - affecting more than two segments of the body.

Dystonia results from abnormal functioning of the basal ganglia, a deep part of the brain which helps control coordination of movement. These regions of the brain control the speed and fluidity of movement and prevent unwanted movements. Patients with dystonia may experience uncontrollable twisting, repetitive movements, or abnormal postures and positions. These can affect any part of the body, including the arms, legs, trunk, face and vocal cords.

The majority of early-onset primary dystonias (DYT1), which may appear during childhood or early adulthood, are due to mutations of a gene known that has been mapped to the long arm of chromosome 9 at 9q34.1. DYT6 dystonia is an autosomal dominant primary dystonia that has been mapped to chromosome 8 (8p21q22). It is rarer than DYT1. Other familial primary dystonias identified are DYT7, DYT2, and DYT4, all of which have been noted in specific ethnic groups, primarily of European descent.

Risk Factors:

    Environmental exposure to carbon monoxide, cyanide, manganese, or methanol.

  • Underlying conditions and diseases such as brain tumors, cerebral palsy, Parkinson's disease, stroke, multiple sclerosis, hypoparathyroidism, or vascular malformations.

  • Brain/spinal cord injuries.

  • Inflammatory, infectious, or postinfectious brain conditions.

  • Reactions to certain drugs.

Symptoms:

    Twitches in the hand or foot.

  • Tremors and cramps.

  • Spasms in jaw muscles.

  • Loss of coordination.

  • Muscle pain.

  • Abnormal posture.

  • Anxiety, fatigue, and stress can worsen symptoms.

Diagnosis:

Dystonia usually is diagnosed by a neurologist, and the diagnosis is based on many factors. Other illnesses and disorders that have similar symptoms. During your doctor's appointment your will be asked to provide: A complete medical history, including any family history of dystonia, previous head injury or stroke, or exposure to toxins or drugs.

Test include:

    Blood or urine samples that may reveal the presence of toxins.

  • If there is a family history of dystonia, genetic testing is conducted to look for the DYT1 gene mutation.

  • Your doctor may also request that you have a magnetic resonance imaging (MRI) scan done to look for tumors, lesions or evidence of a stroke.

Treatment:

There are currently no known treatments that can reverse the course of primary dystonia. However, symptoms may be managed well with a combination of therapies. There is a three-tiered approach to relieving dystonia: Botulinum toxin (botox) injections, several types of medication, and surgery. These may be used alone or in combination.

Drug treatment of dystonia is most appropriate in those with generalized/segmental dystonia for whom botulinum toxin would be unlikely to control the full extent of the dystonia. First line treatment is with anticholinergics such as trihexyphenidyl (Benzhexol/Artane). A slow introduction of the drug is very important to avoid side-effects, but some patients, in particular younger patients, can reach very high doses (100mg and above per day), with good effect. Clonazepam is particularly useful for the treatment of tremor, jerks and pain associated with dystonia. Other drugs which are sometimes useful include tetrabenazine, baclofen and even dopamine receptor blocking drugs. As mentioned above, all patients with young-onset dystonia should receive a trial of levodopa. Botulinum toxin has revolutionized the treatment of patients with focal dystonia. Treatment is required every three-four months, and is expensive, but a 70-80% improvement in symptoms is common in most patients, particularly those with blepharospasm and cervical dystonia. Treatment of those with limb dystonia, in particular writer's cramp, is often more difficult and benefit can be inconsistent. Main side effects of treatment are excessive weakness of the treated muscle or spread of effect to nearby muscles (e.g. paralysis of pharyngeal muscles following sternomastoid injections). Immune-mediated resistance to botulinum toxin is seen in a small proportion of chronically treated patients, particularly those who receive high doses, “top-up” doses, or injections more frequently than every 12 weeks. An alternative toxin, botulinum toxin type B is available, but antibodies to the commonly used type A toxin can be cross-reactive with type B toxin, and in addition, a primary immune response to type B toxin can also occur. Botulinum toxin can be helpful for those with generalized dystonia where a particular functional problem can be linked to dystonia in a single or a small group of muscles.

Surgery is considered when other treatments have proven ineffective. The goal of surgery is to interrupt the pathways responsible for the abnormal movements at various levels of the nervous system. Some operations purposely damage small regions of the thalamus (thalamotomy), globus pallidus (pallidotomy), or other deep centers in the brain. Deep brain stimulation (DBS) has been tried recently with some success. Other surgeries include cutting nerves leading to the nerve roots deep in the neck close to the spinal cord (anterior cervical rhizotomy) or removing the nerves at the point they enter the contracting muscles (selective peripheral denervation).

The benefits of surgery should always be weighed carefully against its risks.

Disclaimer: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.

DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.

0 Comments

Submit a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Cart Preview

Being Married May Cut the Risk of Heart Disease and Stroke

Being Married May Cut the Risk of Heart Disease and Stroke

According to a recent analysis of existing studies in the UK, single, divorced and widowed people have higher chances to develop heart disease and stroke. That’s why the authors of the study believe that being married can be another factor that cuts the risk of...

These 10 Things Happen to Your Body When You Overeat

These 10 Things Happen to Your Body When You Overeat

All of us at least once in life overate – you’re appearing at a birthday party with the intention not to eat too much but then something goes completely wrong. Give a look at what’s happening to your body when you overeat. Maybe this will help you to stop eating at...

Quiz about this article

Please answer on few questions to make our service more useful

Featured Products

Spring is Here: Top 6 Outdoor Sports

Good weather is the best reason to do outdoor sports, which will help not only lose weight, but also will strengthen health. Bicycle The sun dries out the local paths, so you can safely sit on your favorite bike and confidently twist the pedals, where the eyes look....

read more

First Aid in Case of Injuries for Sport and Exercise

First aid for injuries consists of simple rules that need to be clearly implemented. If this is a closed injury, you need to immobilize the injured limb, otherwise the person may lose consciousness from a painful shock. If you need to get to the emergency room...

read more