Effects of subthalamic nucleus stimulation on actual and imagined movement in Parkinson's disease : a PET study.
BACKGROUND
PET studies in moderately affected Parkinson's disease (PD) patients reveal abnormal cerebral activation during motor execution and imagery, but the effects of subthalamic nucleus (STN) stimulation are not well established.


OBJECTIVE
to assess the effect of STN stimulation on cerebral activation during actual and imagined movement in patients with advanced PD.


METHODS
seven severely affected PD patients treated with bilateral STN stimulation were studied with PET and H(2)(15)O. The following conditions were investigated: (1). rest; (2). motor execution of a sequential predefined joystick movement with the right hand and (3). motor imagery of the same task. Patients were studied with and without left STN stimulation while right stimulator remained off.


RESULTS
Without STN stimulation, the primary motor cortex was activated only during motor execution whereas the dorsolateral prefrontal cortex (DLPFC) was activated only during motor imagery. An activation of the supplementary motor area (SMA) was seen during both motor execution and motor imagery. Left STN stimulation during motor execution increased the regional cerebral blood flow (rCBF) bilaterally in the prefrontal cortex including DLPFC, in the left thalamus and putamen. In addition, a reduction of rCBF was noted in the right primary motor cortex, inferior parietal lobe and SMA. Under left STN stimulation, during motor imagery, rCBF increased bilaterally in the DLPFC and in the left thalamus and putamen and decreased in the left SMA and primary motor cortex.


CONCLUSIONS
STN stimulation during both motor execution and imagery tends to improve the functioning of the frontal-striatal-thalamic pathway and to reduce the recruitment of compensatory motor circuits notably in motor, premotor and parietal cortical areas.
Thobois
Stéphane
S
Service de Neurologie D, Hôpital Neurologique Pierre Wertheimer, Lyon, France.stephanie.thobois@chu-lyon.fr
Dominey
Peter
P
Fraix
Valérie
V
Mertens
Patrick
P
Guenot
Marc
M
Zimmer
Luc
L
Pollak
Pierre
P
Benabid
Alim-Louis
AL
Broussolle
Emmanuel
E
D000368:Aged; D000704:Analysis of Variance; D002560:Cerebrovascular Circulation / Q000502:physiology; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D006801:Humans; D007092:Imagination / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000503:physiopathology*; D020531:Subthalamic Nucleus / Q000098:blood supply / Q000000981:diagnostic imaging / Q000502:physiology*; D014055:Tomography, Emission-Computed / Q000379:methods*