ABSTRACT
Dystonia is a syndrome of sustained muscle contractions, frequently causing twisting and repetitive movements or abnormal postures. Historically, dystonia has been divided into primary (idiopathic) and secondary etiologies. Primary dystonias are disorders in which dystonia is the only feature, is the primary feature and accompanied only by other movement disorders (e.g., myoclonus or parkinsonism), or the cause is either a specific genetic mutation or is unknown. The two most important types of primary dystonia in children are dopa-responsive dystonia (DRD) and idiopathic torsion dystonia associated with the DYT1 mutation. Secondary dystonias are those disorders in which the dystonia is due to another identifiable cause. The most important etiologies of secondary dystonia in children are listed in Table 1.
