Cervical Dystonia Resolving After the Onset of Parkinson's Disease.

Dystonia can occur in Parkinson's disease (PD). Dystonia usually presents during the course of the disease or as a side effect of medication. The development of cervical dystonia (CD) before the onset of PD is uncommon but has been described. Complete resolution of CD has not been described to date. We demonstrate a 71-year-old man with a four-year history of CD, who presented with prodromal PD symptoms. Three years later, he was diagnosed with PD. Shortly after initiating treatment for PD, his cervical dystonia started to improve, and eventually, he had complete resolution of CD approximately after two years of PD treatment. In conclusion, the pathological basis of this association is not well understood, but it is important to note that the globus pallidus internus (GPi) plays an important role in connecting these two disorders at a pathological level and as a target for surgery. Increased activity in the GPi may cause resolution of the CD by decreasing unintentional thalamocortical activity.