Levodopa-induced dyskinesia is preceded by increased levels of anxiety and motor impairment in Parkinson's disease patients.

Introduction : Dopamine replacement therapy with levodopa is the gold standard treatment of Parkinson's disease (PD); however long-term levodopa use is associated with abnormal involuntary movements known as levodopa-induced dyskinesia (LID) in most patients. LID is not preventable and represents the major limitation of PD treatment. Objective : This study was aimed to find clinical and behavioral features that could be used to identify, years in advance, PD patients that are at high risk of developing LID in the future. Method : Data from PD patients enrolled in The Parkinson's progression markers initiative (PPMI, Michael J. Fox Foundation) that developed dyskinesia during their participation in the study were compared with those who did not, and with healthy controls. Result : LID was preceded byhigher levels of trait anxiety and increased motor impairment in PD patients. Additionally, younger age at PD diagnosis, earlier need for dopaminergic therapy and higher initial levodopa dose, were associated with future development of dyskinesia. Conclusion : These findings suggest that easily detectable clinical and behavioral alterations may help to identify PD patients that are more susceptible to develop LID.