Subdural motor cortex stimulation in Parkinson's disease does not modify movement-related rCBF pattern.

There has been some evidence that electrical stimulation of the primary motor cortex (MCS) may relieve motor symptoms of Parkinson's disease (PD). This surgical technique is being studied as alternative for PD patients who are considered poor candidates for deep brain stimulation (DBS) of subthalamic nucleus (STN). In 4 PD patients with unilateral MCS, we used [(15)O] H(2)O positron emission tomography to measure changes in regional cerebral blood flow (rCBF) while testing motor performance with a joystick motor task during different stimulation frequencies, OFF-condition, 50 and 130 Hz. We found that different stimulation settings did neither improve performance on joystick task nor modify the pattern of movement-related rCBF. Similarly, no changes were observed in UPDRS motor score between Off and On stimulation while off medication. We conclude that while MCS may be a simpler and safer surgical procedure than DBS of STN, it failed to provide evidence of clear effect on motor performance and movement-related activation pattern in patients with advanced PD.