Dystonia: Cause
Dystonia may be further classified based upon its cause. More specifically, dystonia may be categorized according to its causes as follows:
- Primary (idiopathic) dystonia—dystonia is the only sign and a secondary cause is ruled out.
- Secondary (symptomatic) dystonia—dystonia results primarily from environmental causes, underlying disease, which may or may not be genetic, or injury to the brain.
- Dystonia-plus syndromes—this classification refers to nondegenerative, neurochemical disorders in which dystonia is associated with other neurologic features, such as myoclonus or parkinsonism.
- Heredodegenerative dystonia—this category refers to usually hereditary, neurodegenerative disorders in which other neurologic symptoms are present in addition to dystonia.
