Deep Brain Stimulation of the Subthalamic Nucleus and its Effect on Gait in Parkinson Disease
Author:
Jacqueline Zak ’24Co-Authors:
Faculty Mentor(s):
Karlo A. Malaga, Biomedical EngineeringFunding Source:
The Emerging Scholars Program and the James L.D. and Rebecca Roser Research FundAbstract
Deep brain stimulation (DBS) is a surgical procedure where electrodes are implanted in the brain to modulate specific regions with electricity. This stimulation can alleviate gait disturbances in Parkinson disease (PD). DBS modeling can be used to estimate the spatial extent of stimulation, enabling individualized treatment. Although the standard DBS target for PD is the subthalamic nucleus (STN), a generalized approach may not be optimal for every patient due to the diversity of their symptoms. Better outcomes may be obtained by stimulating regions around the STN.
Forty PD patients who received bilateral STN DBS were included in this study. For each patient, the location of therapeutic stimulation was calculated using tissue activation models built from individualized imaging data and stimulation settings. The volume of tissue activation (VTA) was used to quantify STN and external (non-STN) activation in the lateral-medial, anterior-posterior, and dorsal-ventral directions. The relationship between STN/external activation and symptom improvement (gait, freezing of gait, postural stability, and total gait) was evaluated. A similar analysis was performed for electrode location (the distance between the active contact and STN centroid).
A significant positive relationship between anterior STN activation and total gait improvement was found (p < 0.01). No significant relationships were found for the external activation and electrode location analyses. Results suggest that more anterior STN stimulation may be preferable for patients whose primary symptoms are gait disturbances. Furthermore, VTAs may provide more information about stimulation location than active contacts and highlight the importance of patient- and symptom-specific targeting.