Effects of STN-DBS surgery on cerebral glucose metabolism and distribution of DAT in Parkinson's disease.

Abstract

Parkinson's disease (PD) is a neurodegenerative disorder that affects millions of people worldwide. Subthalamic nucleus (STN) deep brain stimulation (DBS) has been shown to be an effective treatment for PD; however, the effects of this surgery on cerebral metabolism and presynaptic dopamine transporter (DAT) distribution are still being studied. In this study, we included 12 PD patients (6 male and 6 female) who underwent STN-DBS surgery and had both 18 F-FDG and 11 C-CFT PET/CT imaging before and 1 year after the surgery. We used paired t-tests to identify changes in cerebral metabolism and calculated PD-related metabolic covariance pattern (PDRP) scores. We also assessed the uptake of 11 C-CFT in the striatum using striatal-to-occipital ratios (SORs). One year after surgery, we observed significant reductions in tremor, rigidity, akinesia, postural instability/gait disturbance, and Unified Parkinson's Disease Rating Scale Part III scores (p<.01, p<.001, p<.001, p<.001, and p<.001, respectively). Hamilton Depression Rating Scale and quality of life (PDQ-39 SI) were also significantly reduced (p<.05 and p<.01, respectively). The mean PDRP score decreased by 37% from 13.0±6.6 to 8.2±7.9 after STN-DBS surgery (p<.05). We observed decreased 18 F-FDG uptake in several areas, including the temporal lobe (BA22), thalamus, putamen, and cingulate gyrus (BA24), whereas it was increased in the supplementary motor area, postcentral gyrus, lingual gyrus, and precuneus (p<.05). SORs of 11 C-CFT in the bilateral caudate nucleus and ipsilateral posterior putamen were significantly decreased compared to preoperative levels (p<.05). Our findings suggest that STN-DBS surgery modifies the metabolic network of PD patients and improves motor symptoms, depression, and quality of life. However, it does not prevent the decrease of DAT in striatal areas.