Disruption in Cerebellar and Basal Ganglia Networks During a Visuospatial Task in Cervical Dystonia

Background: Although dystonia is traditionally conceptualized as a basal ganglia disorder, increasing interest has been directed at a different neural network node, the cerebellum, which may play a significant role in the pathophysiology of dystonia. Abnormal sensorimotor processing and disturbed motor schemes, possibly attributable to cerebellar changes, remain unclear. Methods: We sought to characterize the extent of cerebellar dysfunction within the motor network using functional MRI activation analysis, connectivity analysis, and voxel-based morphometry in cervical dystonia patients ( n525, 15 women, mean age 45.8 years) and healthy volunteers ( n525, 15 women, mean age 44.7 years) in a visuospatial task requiring predictive motor timing. Results: Cervical dystonia patients showed decreased activation in the posterior cerebellar lobules as well as in the premotor areas, the associative parietal cortex, and visual regions. Patients also had decreased cerebellar connectivity with bilateral basal ganglia structures and the dorsolateral prefrontal cortex. Conclusions: This promotes the view that dystonia results from miscommunication between the basal ganglia and cerebellar loops, thus providing new insights into the brain regions essential for the development of cervical dystonia. (C) 2017 International Parkinson and Movement Disorder Society