Neuroimaging in dystonia

Dystonia is a hyperkinetic movement disorder characterized by the involuntary, simultaneous, and sustained contraction of antagonistic muscles causing abnormal postures and movements. Different forms of dystonia affect different regions of the body. Dystonia can be either idiopathic, genetic, or acquired. At present, the exact etiopathogenesis remains unknown. Currently, postulations including the role of corticostriatal–thalamocortical motor circuits within dystonia genesis have been put forward. Neuroimaging within dystonia is an extremely valuable means to enable further examination and understanding of the mechanisms involved in dystonia pathophysiology. Several neuroimaging modalities have been used within dystonia; structural changes have been investigated using magnetic resonance imaging (MRI) techniques such as volumetric MRI and diffusion tensor imaging. Further functional alterations have been observed using functional MRI. Positron emission tomography and single-photon emission computerized tomography scanning can give details regarding GABAergic and dopaminergic pathways and investigate metabolic performance as well as cerebral perfusion within dystonia. Within this chapter, we will present and review the results from the current research base of neuroimaging studies in dystonia.