Dystonia and its disorders

Dystonia is a movement disorder characterized by sustained muscle contracti ons, frequently causing twisting and repetitive movements or abnormal postu res. The term dystonia does not signify a single disease, but instead descr ibes a symptom and sign that may be part of many disorders with a variety o f causes. Dystonia may be classified by age of onset, distribution of sympt oms, or by etiology. An increasing number of genetic forms of dystonia have been recognized and the findings have advanced knowledge of underlying neu ral mechanisms of pathogenesis. Options for treatment of dystonia include p harmacological therapy, botulinum toxin injection, or neurosurgical procedu res.