Deep brain stimulation of the subthalamic nucleus versus levodopa challenge in Parkinson's disease: measuring the on- and off-conditions with FDG-PET.

In order to compare the effects of high-frequency stimulation of the subthalamic nucleus (STN-DBS) and a levodopa-challenge on cerebral metabolic activity, we conducted PET scans with [(18)F]2-fluoro-2-deoxyglucose (FDG) in the drug- and stimulation- on- and off-condition in a single patient suffering from advanced PD. Our data revealed evidence for improved thalamocortical processing released from inhibition by overactive basal ganglia output nuclei in both on-conditions. While levodopa also led to a reduction of lentiform hyperactivity, effective STN stimulation seemed to interfere with distinct cerebellar and limbic circuits.