Dystonia is a neurological movement disorder characterised by inappropriate and involuntary muscle movements. It is often misdiagnosed. The disabling, repetitive and sustained muscle spasms and twisting typical of dystonia are thought to be due to malfunction of a particular part of the brain, the basal ganglia.
Faulty signals from the brain cause muscles to spasm and pull on the body incorrectly. This forces the body into twisting, repetitive movements or abnormal postures. Sometimes the symptoms are accompanied by dystonic tremor.
Unfortunately there is not yet a cure. However, in the vast majority of cases, dystonia does not shorten a person’s life span.
Treatments are available and most people do manage to develop successful strategies for living with dystonia combining treatment with pain control and sensory tricks to help with social situations. Remission from symptoms does sometimes occur but is rare – occurring in around 5-10% of cases.
Basal Ganglia and dystonia
Usually, when a movement is made, excitation and inhibition work in harmony so contraction of the agonist muscles is coordinated with relaxation of the antagonist muscles. In patients with dystonia there is deficient inhibition of the antagonist muscles. This can result in co-contraction, where the agonist and antagonist muscles contract together.
Research has identified that the major role of the basal ganglia is to balance excitation and inhibition (just like a pair of scales). However, in dystonia this delicate balance is not attained. It is not yet certain whether the problem is with the direct pathway, the indirect pathway or both. However, as dystonia appears to result from insufficient inhibition in the muscles, it may be that the indirect pathway is failing, resulting in impaired suppression of muscle activity. The lack of inhibition of antagonist or surrounding muscles ultimately causes the co-contraction or overflow phenomena seen in dystonia.
One area of focus has been to look at whether dystonia is caused by a shortage of the inhibitory neurotransmitter GABA. It seems plausible that a shortage of an inhibitory neurotransmitter such as GABA may play a role, since dystonia seems to be a failure of inhibition. At present this is a theory that remains unproven; however, one of the treatments for dystonia, which helps in some cases, is to prescribe medications that increase the quantity of GABA such as benzodiazepines, gabapentin or baclofen.
Courtesy of http://www.dystonia.org.uk/
Types of dystonia
Dystonia is either:
- Generalised – most common in young patients
- Focal – starts in adulthood, affecting one or more parts of the body
Dystonia Patient Network 