Video 1
Visualization of patient’s tremor over time. Demonstration of preoperative, intraoperative, and postoperative handwriting, Archimedes’ spiral, and line drawings.
Figure 1
Intraoperative electrophysiology recordings. One second interval microelectrode recordings representing the electrophysiology through basal ganglia structures, including the thalamus (blue), VIM (green), and thalamic fasciculus (purple). The lead in the figure provided the authors an objective measure to confirm the depth of the electrophysiology displayed, and demonstrated the scale and location in reference to the VIM where the microelectrode recordings occurred.
Figure 2
BrainLab (Munich, Germany) image displaying the three trajectories the patient had implanted during the DBS procedure, and the Vo/VIM DBS trajectory from Fukaya (2007). The arrow from the terminal lead (pink) observed in panels A – D portrays the directionality of the electrode. Coordinates in panels A–C are in reference to the MCP of our patient, the coordinates in D are the means from the Fukaya trajectory (6). All images are shown at the center of the intended target and all Archimedes’ spirals were conducted intraoperatively. The white asterisks overlaid on each track (panels A–C) represents the location where the Archimedes’ spiral were obtained. A: In green is the anterior trajectory from center. The blue track originating from the distal end of the green trajectory represents the implanted electrode into the STN. The tip of the electrode extended –3.5 mm inferior to the MCP into the STN. Panel B: The yellow trajectory (center track) was intended to span the targeted brain areas. Comparison of Archimedes’ spirals between panel A and B shows slight clinical improvement in track one. Panel C: the pink lead represents the third track that targeted the VIM and produced the best clinical outcomes without adverse effects, as seen by comparison of Archimedes’ spirals. Panel D: The Fukaya Vo/VIM electrode (in purple) was overlayed on our three trajectories for comparison of electrode positioning. The electrode was modified based upon their case description by removing the distal contact and made blunt (6).
Figure 3
Comparison Archimedes’ of spirals, stimulation parameters and Volume of Tissue Activation (VTA) in red. Using preoperative MRI and postoperative CT imaging, the VTA was modeled from patient stimulation parameters and created with LeadDBS [21] and Fastfield [22], which does not take frequency into account. The VTA represents simulation meant to target the VIM, seen as time progresses. Archimedes’ spirals improved as stimulation was applied to the VIM when compared to preoperative measures (panel A). The motor scales remained stable postoperatively at one month (panel B), two moths (panel C), and ten months (panel D). The high overlap of VTA onto the VIM displays that the VIM is primarily stimulated and relates to the improved motor scales demonstrated in panels B–D.