(A) CLINICAL CHARACTERISTICS OF DYSTONIA |
Age of onset (infancy, childhood, adolescence, and early/late adulthood) |
Body distribution |
Focal (only one body region is affected. e.g., blepharospasm) |
Segmental (two or more contiguous body regions are affected) |
Multifocal (two non-contiguous or more – contiguous or not – body regions are involved) |
Hemidystonia (more body regions restricted to one body side are involved) |
Generalized (involvement of the trunk and at least two other sites, including leg or not) |
Temporal pattern |
Course of disease (static or progressive) |
Variability |
Persistent (appears to approximately the same extent throughout the day) |
Diurnal (recognizable circadian variations in occurrence, severity and phenomenology) |
Action-specific (occurs only during a particular activity or task) |
Paroxysmal (sudden self-limited episodes of dystonia usually induced by a trigger) |
Associated features |
Isolated dystonia (dystonia is the only sign, with the exception of tremor) |
Combined with other movement disorders (e.g., myoclonus) |
Associated with other neurological symptoms (e.g., cognitive decline) or systemic manifestations (e.g., Wilson disease) |
(B) ETIOLOGY |
Nervous system pathology |
Evidence of degeneration |
Evidence of structural (often static) lesions |
No evidence of degeneration or structural lesion |
Inherited or acquired |
Inherited (autosomal dominant, autosomal recessive, X-linked recessive, and mitochondrial) |
Acquired (brain injury, infection, drug, toxic, vascular, neoplastic, and psychogenic) |
Idiopathic (sporadic and familial) |