Combination of Multi-Modal Imaging and Neurophysiology to Improve Targeting Accuracy and Outcome in Deep Brain Stimulation for Movement Disorders

A study was conducted to observe the positioning of two sets of electrodes in fourteen patients with Parkinson’s disease (PD). The purpose was to potentially optimise electrode positioning and parameters with the goal of possibly benefiting patient outcome. Boston scientific electrodes were the multi-directional electrodes (also known as directional) and Medtronic 3389 were the conventional electrodes, each set had been previously surgically inserted into PD patients with pre- and post-operative imaging data available. The corresponding data was input into Lead DBS software to identify the hypothetical electrode position in silico. A target point within the most central point of the motor region of subthalamic nucleus (mSTN) was selected with the corresponding distance measured from the active contact of each patient electrode. The mean electrode distance observed from the target point to active contact in all patients was (right) 6.52 millimeter (mm) (SD=2.75, SE=0.83) and (left) 5.91mm (SD=2.83, SE= 0.82). The mean voltage was (right) 1.36V (SD=0.74, SE=0.2) and (left) 1.64V (SD=0.89, SE=0.25). No UPDRS data was available due to limited access to databases as a result of travel restrictions imposed rendering the study qualitative in nature. It was not possible to determine what electrode would be more successful to alleviate symptoms given the small cohort in each arm of the study. It was also not possible to determine if Diffusion tensor imaging (DTI) could be used as a tool in aiding in the reduction of volume of tissue activated outside of the desired area again due to low numbers of DTI data sets available. This study was able to optimize electrode parameters within Lead-DBS; however, this could not be replicated in a clinical setting as further research would be required to validate the results of this study. No firm conclusion can be drawn between the advantages and disadvantages of each type of electrode.