BACKGROUNDThe major neuropathological symptoms of Parkinson's disease (PD) consist of a loss of pigmented dopaminergic neurons in the substantia nigra and the presence of Lewy bodies. This study was to investigate the effects of bilateral subthalamic nucleus (STN) stimulation on resting-state cerebral glucose metabolism in advanced PD, and investigate the mechanism of deep brain stimulation (DBS).

METHODSSeven consecutive advanced PD patients (4 men and 3 women, mean age 64 +/- 4 years, mean H-Y disability rating 4.4 +/- 0.65) receiving bilateral STN DBS underwent 18F-fluorodeoxyglucose (18F-FDG)/positron-emission tomography (PET) examinations at rest both preoperatively and one month postoperatively, with STN stimulation still on. The unified PD rating scale was used to evaluate the clinical state under each condition. Statistical parametric mapping (SPM) was used to investigate the regional cerebral metabolic rates of glucose (rCMRGlu) during STN stimulation, and to compare these values to rCMRGlu preoperation.

RESULTSSTN stimulation clearly improved clinical symptoms in all patients. A significant increase in rCMRGlu was found in the bilateral lentiform nucleus, brainstem (midbrain and pons), bilateral premotor area (BA6), parietal-occipital cortex, and anterior cingulated cortex, and a marked decrease in rCMRGlu was noted in the left limbic lobe and bilateral inferior frontal cortex (P < 0.05).

CONCLUSIONBilateral STN stimulation may activate the projection axon from the STN, improving clinical symptoms in advanced PD patients by improving both ascending and descending pathways from the basal ganglia and increasing the metabolism of higher-order motor control in the frontal cortex.