Subthalamic Nucleus DBS Placement for Parkinson’s Disease: Use of the microTargeting™ Frame and Waypoint™ Stereotactic System with MER Guidance

The subthalamic nucleus (STN) target is frequently employed as a deep brain stimulation (DBS) target for the treatment of Parkinson’s disease. This target offers the advantage of tremor reduction and L-Dopa medication reduction. When compared with other targets for the treatment of PD, such as the globus pallidus interna (GPi), some practitioners feel that the STN target may lead to greater reduction in impulse control, worsened cognitive deficits, and increased balance problems. Modern rapid prototyping methods, such as 3D printing, have made it possible to create custom skull-mounted stereotactic mini-frames (microTargeting™ platform) specific to a given patient and target. The microTargeting™ platform is a complete stereotactic system that offers several advantages including greater patient comfort, shorter surgical time on the day of lead implantation, reduced capital cost, and a shorter distance to target. Disadvantages of the system include the requirement of an extra patient visit, because the frame must be planned with imaging on a day separate from the operative day, and some constraints on targeting trajectories on the day of surgery. Waypoint planning software is coupled with the microTargeting™ platform for the purpose of trajectory planning and frame creation. Waypoint planning software includes a probabilistic atlas based on a historical cohort of patients that previously underwent DBS placement, and it can be used as an adjunct to standardized coordinates in choosing the specific location of the STN target. After the trajectories are planned and the microTargeting™ frame is produced, it is affixed to the patients’ skull on the day of lead placement. From this point, bur hole creation proceeds in the standard manner and microelectrode recording can occur simultaneously, if necessary, through both planned trajectories. Reducing the time necessary to affix the frame and plan the case on the day of surgery provides more time for MER and test stimulation and may improve patient cooperation, by shortening the surgical time.