GPi LFP Activity is Marked by Increased High Frequency (200-300 Hz) Power in PD PatientsChristos Tsiokos11Los Angeles, CA United States Keywords: microelectrode recording, electrode, globus pallidus, neurophysiological monitoring, Parkinson's Disease
Our study aimed to identify unique electrophysiological signatures in the Globus Pallidus internus (GPi) that would be helpful for targeting DBS electrodes and to eventually create a closed-loop circuit for more effective stimulation. The beta and gamma sub-bands have been the main focus of studies on the basal ganglia due to their connection to functional states of the brain and their spatiotemporal characteristics.
High frequency components (200-300Hz) have not been shown to vary substantially in space inside wever, and near the GPi and our study is one of the first to examine GPi LFP activity comprehensively, as most have focused on the STN.
Local field potentials (LFPs) were recorded intraoperatively at sixteen positions along a 24 mm trajectory to the GPi of PD patients. Signals were recorded (2400 Hz sampling) for 60 seconds for each location during both rest and contralateral hand movement. Using a common average reference, we evaluated normalized spectral power at each contact position for frequencies up to 400 Hz using a Welch''''s periodogram.
During both the movement and resting phases, a significant increase in normalized high-frequency power (200-300Hz) was noted at target regions within the GPi, compared to more caudal regions outside the target region. Normalized beta band power was also significantly higher within the GPi at target.
This is a retrospective study.
We present the first report of a potentially clinically and physiologically important electrophysiological signature of the diseased GPi in patients with Parkinson.
C. Tsiokos ()