Pathophysiology and definition Dystonia is a movement disorder in which a person's muscles contract uncontrollably. The contraction causes the affected body part to twist involuntarily, resulting in repetitive movements or abnormal postures. Dystonia can affect one muscle, a muscle group, or the entire body. Dystonia affects about 1% of the population, and women are more prone to it than men.
Symptoms: Dystonia can range from very mild to severe. It can affect different body parts, and often the symptoms of dystonia progress through stages. Some early symptoms include: • A "dragging leg" • Cramping of the foot • Involuntary pulling of the neck • Uncontrollable blinking • Speech difficulties Stress or fatigue may bring on the symptoms or cause them to worsen. People with dystonia often complain of pain and exhaustion because of the constant muscle contractions. If dystonia symptoms occur in childhood, they generally appear first in the foot or hand. But then they quickly progress to the rest of the body. After adolescence, though, the progression rate tends to slow down. When dystonia appears in early adulthood, it typically begins in the upper body. Then there is a slow progression of symptoms. Dystonias that start in early adulthood remain focal or segmental: They affect either one part of the body or two or more adjacent body parts.
CAUSES: Most cases of dystonia do not have a specific cause. Dystonia seems to be related to a problem in the basal ganglia. That's the area of the brainthat is responsible for initiating muscle contractions. The problem involves the way the nerve cells communicate. Acquired dystonia is caused by damage to the basal ganglia. The damage could be the result of: • Brain trauma • Stroke • Tumor • Oxygen deprivation • Infection • Drug reactions • Poisoning caused by lead or carbon monoxide Idiopathic or primary dystonia is often inherited from a parent. Some carriers of the disorder may never develop a dystonia themselves. And the symptoms may vary widely among members of the same family.
TREATMENT: There are a number of treatment techniques that can control the involuntary movements and spasms of dystonia, including medication, physiotherapy, and in some cases, surgery. The aim is to provide relief from the abnormal movements and postures of dystonia, plus any associated pain and discomfort. In some cases, other conditions that arise as a result of dystonia, such as stress, anxiety or depression, may also need to be treated. Treatment for dystonia should be based on the individual and their specific needs. As different people respond differently to different treatments, it may be necessary to try several options to find out which one works best. There are four main types of treatment for dystonia. They are: • botulinum toxin • medication • physiotherapy • surgery, including deep brain stimulation (DBS)
STATISTICS: he prevalence estimates presented here are the most pre-cise currently available and enable us to examine age- andsex-speci?c rates for several focal sub-types. However,they are clearly not the most accurate as the methods of case ascertainment will those cases that were have missed undiagnosed casesand also relevant specialist either misdiagnosed or notreferred to the For example,the surveycarried out in the north of England  identi?ed 3 previously undiagnosed cases out of a total of 19 patients(16%).Despite these limitations our results are similar to andconsistent with those of other studies,which have usedmore exhaustive methods of case ascertainment For example,our rates forboth multifocal andsegmental dystonia are,ifanything,greater than those thatcan be calculated from the northern England study(multi-focal 0.8 per million,segmental 15.0 per million).