Changes in cerebral activity pattern due to subthalamic nucleus or internal pallidum stimulation in Parkinson's disease

TLDR

High‑frequency electrical stimulation of the internal pallidum (GPi) or the subthalamic nucleus (STN) improves clinical symptoms of Parkinson’s disease. The study evaluated whether changes in movement performance were accompanied by changes in regional cerebral blood flow (rCBF) in 12 parkinsonian patients, six with STN and six with GPi stimulators, using H₂¹⁵O positron emission tomography. Patients were scanned at rest and while performing a free‑choice joystick movement under effective and ineffective electrostimulation, allowing comparison of movement‑related rCBF changes. Effective STN stimulation produced greater movement‑related increases in rCBF in the supplementary motor area, cingulate cortex, and dorsolateral prefrontal cortex than ineffective stimulation, whereas GPi stimulation showed no significant changes; the difference was mainly localized to DLPFC, confirming the dominant role of nonprimary motor areas and the importance of STN input in movement control in Parkinson’s patients.

Abstract

Abstract High‐frequency electrical stimulation of the internal pallidum (GPi) or the subthalamic nucleus (STN) improves clinical symptoms of Parkinson's disease. In 12 parkinsonian patients, 6 with STN and 6 with GPi stimulators, we used H 2 15 O positron emission tomography to evaluate whether changes in movement performance were accompanied by change in regional cerebral blood flow (rCBF). Patients were scanned both at rest and while performing a free‐choice joystick movement, under conditions of effective and ineffective electrostimulation. During effective STN stimulation, movement‐related increases in rCBF were significantly higher in supplementary motor area, cingulate cortex, and dorsolateral prefrontal cortex (DLPFC) than during ineffective stimulation. No significant change was observed in any of these areas during GPi stimulation. The difference between the effect of STN and GPi stimulation on movement‐related activity was mainly localized to DLPFC. These results confirm the dominant role of nonprimary motor areas in the control of movement in parkinsonian patients and demonstraste the importance of STN input in the control of these areas.