Dystonia is a movement disorder characterized by sustained muscle contractions, repetitive
twisting movements, and abnormal postures of the trunk, neck, face, or arms and legs.
Dystonia is often confused with spasticity or rigidity and is even mistakenly attributed to
psychogenic causes. This review covers recent advances in the causes and treatment of
both primary and secondary dystonias, including those that are drug-induced, related to
acquired brain lesions, or part of heredodegenerative syndromes.