[Pathophysiology in dystonia: functional anatomy of basal ganglia]

Clinical manifestation of dystonia features involuntary muscle contraction or spasm resulting in postural and movement disorders. Depending on the distribution and spreading pattern of dystonia, four patterns have been described, including focal, segmental, multifocal and generalized dystonia. Dystonia can be seen as one of additional clinical features in a more severe neurologic condition. Most of pathophysiology in dystonia remains to be elucidated. Considering the pathology in secondary dystonia, basal ganglia is mostly involved, especially putamen. Dysfunctions of the cerebello-thalamo-cortical loop would result in development of dystonia. Stereotactic and functional neurosurgery has been demonstrated to provide clinical benefits to dystonia patients. In addition, involvement of other neuronal circuit or tissue has been revealed, including cerebello-thalamo-cortical loop, brainstem, spinal cord and peripheral nervous system. Elucidation of pathophysiology, molecular genetics, and functional neuroanatomy would further contribute to developing therapeutic strategy in dystonia.