Directional Local Field Potentials in the Subthalamic Nucleus During Deep Brain Implantation of Parkinson’s Disease Patients

Abstract

Segmented deep brain stimulation leads feature directional electrodes that allow for a finer spatial control of electrical stimulation compared to traditional ring-shaped electrodes. These segmented leads have demonstrated enlarged therapeutic windows and have thus the potential to improve the treatment of Parkinson's disease patients. Moreover, they provide a unique opportunity to record directional local field potentials. Here, we investigated whether directional local field potentials can help identify the best stimulation direction to assist device programming. Four Parkinson's disease patients underwent routine implantation of the subthalamic nucleus. Firstly, local field potentials were recorded in three directions for two conditions: In one condition, the patient was at rest; in the other condition, the patient's arm was moved. Secondly, current thresholds for therapeutic and side effects were identified intraoperatively for directional stimulation. Therapeutic windows were calculated from these two thresholds. Thirdly, the spectral power of the total beta band (13-35 Hz) and its sub-bands low, high, and peak beta were analyzed post hoc. Fourthly, the spectral power was used by different algorithms to predict the ranking of directions. The spectral power profiles were patient-specific, and spectral peaks were found both in the low beta band (13-20 Hz) and in the high beta band (20.5-35 Hz). The direction with the highest spectral power in the total beta band was most indicative of the 1 st best direction when defined by therapeutic window. Based on the total beta band, the resting condition and the moving condition were similarly predictive about the direction ranking and classified 83.3% of directions correctly. However, different algorithms were needed to predict the ranking defined by therapeutic window or therapeutic current threshold. Directional local field potentials may help predict the best stimulation direction. Further studies with larger sample sizes are needed to better distinguish the informative value of different conditions and the beta sub-bands.

Combining Multimodal Biomarkers to Guide Deep Brain Stimulation Programming in Parkinson Disease

“…A promising approach to inform DBS programming is by taking advantage of electrophysiological recordings from the implanted DBS lead. There is a large body of literature linking Parkinson disease (PD) symptoms to spectral features in basal ganglia signals, with exaggerated beta activity (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) being the best characterized. The latter is suggested to exhibit a limiting effect on the information coding capacity within the motor circuitry 8 and thereby provoking bradykinesia and rigidity symptoms.…”

“…[14][15][16] However, there are other potentially informative features, such as movement-related desynchronization of beta activity, which is associated with improved motor performance and localizes to the motor STN. [17][18][19][20] Gamma activity (60-100 Hz) synchronizes with movement, is viewed as prokinetic signal, and is also evident in the dorsal STN. [21][22][23] High frequency oscillations (HFO) are similarly modulated as gamma activity, with the modulation being negatively correlated to bradykinesia scores.…”

Differential dopaminergic modulation of spontaneous cortico–subthalamic activity in Parkinson’s disease

“…Moreover, we used directional contacts, which have a smaller surface area than the classical ring contacts. Based on the available literature, our sampling rate was high enough to resolve oscillatory activity in the STN ( Telkes et al, 2020 ; Nguyen et al, 2020 ).…”

Differential dopaminergic modulation of spontaneous cortico-subthalamic activity in Parkinson’s disease

“…Based on the available literature, our sampling rate was high enough to resolve oscillatory activity in the STN (Telkes et al 2020;Nguyen et al 2020).…”