Abstract
Quantitative imaging markers to aid in the selection of Parkinson's disease (PD) patients for surgical interventions such as subthalamic nucleus deep brain stimulation (STN-DBS) are currently lacking. Using metabolic PET and network analysis we identified and validated a treatment-induced topography, termed STN StimNet. Stimulation-mediated changes in network expression correlated with concurrent motor improvement in independent STN-DBS cohorts scanned on and off stimulation. Moreover, STN StimNet measurements off stimulation correlated with local field potentials recorded from the STN, whereas intraoperative modulation of cortical activity by STN stimulation correlated with contributions to the network from corresponding brain regions. These findings suggested that stimulation-mediated clinical responses are influenced by baseline StimNet expression. Indeed, we found that motor outcomes following STN-DBS were predicted by preoperative network expression measured using metabolic PET or resting-state fMRI. To illustrate the potential utility of these measures in selecting optimal candidates for DBS surgery, STN StimNet expression was computed in scans from 175 PD patients (0-21 years from diagnosis). The resulting values were used to identify those individuals likely to derive meaningful benefit from a potential STN-DBS procedure. This approach suggests that preoperative network quantification provides unique information regarding baseline brain circuitry, which may be useful in surgical decision making.