Changes in regional cerebral blood flow caused by deep-brain stimulation of the subthalamic nucleus in Parkinson's disease.

UNLABELLED The aim of this study was to investigate the effect of deep-brain stimulation of the subthalamic nucleus (STN) on regional cerebral blood flow (rCBF) throughout the entire brain volume in patients with Parkinson's disease and to evaluate which of the brain areas showing an rCBF increase during STN stimulation related significantly to the improvement in motor function. METHODS Ten consecutive Parkinson's disease patients (6 men, 4 women; mean age +/- SD, 59 +/- 8 y) with bilateral STN stimulators underwent 3 rCBF SPECT examinations at rest: the first preoperatively and the second and third postoperatively (follow-up, 4.8 +/- 1.4 mo) with STN stimulators on and off, respectively. The motor unified Parkinson's disease rating scale, the Hoehn and Yahr disability scale, and the Schwab and England activities-of-daily-living scale were used to evaluate the clinical state under each condition. Statistical parametric mapping was used to investigate rCBF during STN stimulation in comparison with rCBF preoperatively and with STN stimulators off. Also evaluated with statistical parametric mapping was the relationship between rCBF and individual motor scores used as covariates of interest. RESULTS STN stimulation significantly changed rCBF in the right pre-supplementary motor area (pre-SMA), anterior cingulate cortex, and dorsolateral prefrontal cortex and in the medial Brodmann's area 8 (BA8) as defined in the atlas of Talairach and Tournoux (P < 0.05 corrected for multiple comparisons). The rCBF in these areas increased from the preoperative condition to the stimulators-on condition and decreased again after the stimulators were switched off. A significant correlation was detected between the improvement in motor scores and the rCBF increase only in the right pre-SMA and in the anterior cingulate motor area (P < 0.005, uncorrected). CONCLUSION According to the topographic organization of the primate STN, our study shows that stimulation of the STN leads to rCBF increases in the motor (pre-SMA), associative, and limbic territories (anterior cingulate) in the frontal cortex. The significant correlation between motor improvement and rCBF increase in the pre-SMA and the anterior cingulate motor area reinforces the hypothesis that STN stimulation in parkinsonian patients can potentiate the cortical areas participating in higher-order aspects of motor control.