Dopamine Dysregulation Syndrome and Levodopa-Induced Dyskinesias in Parkinson Disease: Common Consequences of Anomalous Forms of Neural PlasticityLinazasoro, Gurutz MDClinical Neuropharmacology: January/February 2009 - Volume 32 - Issue 1 - pp 22-27 doi: 10.1097/WNF.0b013e3181634ea6 Review Article Abstract Author Information Four to 10% of patients with Parkinson disease and chronically treated with levodopa undergo an addictionlike behavioral disturbance named dopamine dysregulation syndrome (DDS). This article suggests that patients with Parkinson disease could be especially prone to develop DDS due to the dopamine deficiency and the "priming" of neural networks by the chronic use of drugs with a short half-life, such as levodopa. These suggestions are based on the clinical and molecular similarities between levodopa-induced dyskinesias and behavioral alterations seen in DDS and addiction to illegal drugs. Motor and behavioral abnormalities can be seen as the consequence of common mechanisms involving anomalous forms of neural plasticity. These forms affect parts of the cortical-basal ganglia-thalamocortical circuits that are topographically organized to differently modulate emotional and motor functions. Recent evidence using positron emission tomography provides support to this idea. By contrast, molecular data suggest that functional segregation may be lost in addiction, DDS, and dyskinesias. The existence of common pathogenic mechanisms for both phenomena could provide the basis for common therapeutic strategies. Centro de Investigación Parkinson, Policlínica Gipuzkoa, San Sebastián, Spain. Address correspondence and reprint requests to Gurutz Linazasoro, MD, Centro de Investigación Parkinson, Policlínica Gipuzkoa, Parque Tecnológico de Miramón, 174, 20009 San Sebastián, Gipuzkoa, Spain; E-mail: email@example.com © 2009 Lippincott Williams & Wilkins, Inc.