Objective: Characterize low-frequency evoked potential (EP) activity induced by deep brain stimulation (DBS) in the internal globus pallidus (GPi) and how the EP dynamics modulate with stimulation parameters and dopaminergic medication in Parkinson’s disease (PD) patients.
Background: PD has been associated with exaggerated synchronized oscillatory activity in the beta band (8-30 Hz) in the basal ganglia thalamocortical (BGTC) network. GPi DBS is an effective treatment option for advanced PD, however, underlying neurophysiological mechanisms are still unclear. Multiple studies have examined short-latency high-frequency oscillations that occur within several milliseconds following a stimulation pulse, and a recent study identified a long-latency, low-frequency EP that has oscillatory activity aligned with endogenous beta activity. However, the role of stimulation site, intensity, and dopaminergic medication on EP dynamics is poorly understood.
Method: Three PD patients were implanted with segmented DBS leads targeting the GPi. Following DBS lead placement, lead extensions were connected and externalized for neuronal recordings. GPi field potentials were recorded from DBS leads at a 24 kHz sampling rate with and without dopaminergic medication. Low-frequency biphasic symmetric stimulation (3Hz with 10% jitter or 3.3 Hz) was delivered to GPi in monopolar or bipolar configurations. Neuronal epochs were aligned to the stimulation pulse and averaged to characterize the temporal and spectral EP dynamics.
Results: We observed that the slower dynamics of the EP had a frequency in the beta band (~24 Hz) range. The evoked amplitude increased with increasing stimulation intensity both in monopolar and bipolar stimulation configurations. EP amplitudes were dependent on the direction of stimulation and decreased after patients were given levodopa. Finally, EP amplitude modulation showed an association with the DBS contact that provided the greatest motor benefits.
Conclusion: These data suggest that EP dynamics could be used as a potential biomarker to optimize DBS parameters and provide the rationale for future development of phase-locked DBS.
References: 1. Schmidt, S. L., Brocker, D. T., Swan, B. D., Turner, D. A. & Grill, W. M. Evoked potentials reveal neural circuits engaged by human deep brain stimulation. Brain Stimulation 13, 1706–1718 (2020).
2. Zapata Amaya, V. et al. Low-frequency deep brain stimulation reveals resonant beta-band evoked oscillations in the pallidum of Parkinson’s Disease patients. Front Hum Neurosci 17, 1178527 (2023).
3. Ozturk, M., Viswanathan, A., Sheth, S. A. & Ince, N. F. Electroceutically induced subthalamic high-frequency oscillations and evoked compound activity may explain the mechanism of therapeutic stimulation in Parkinson’s disease. doi:10.1038/s42003-021-01915-7.
4. Wiest, C. et al. Evoked resonant neural activity in subthalamic local field potentials reflects basal ganglia network dynamics. Neurobiology of Disease 178, 106019 (2023).
5. Rosing, J., Doyle, A., Brinda, A. et al. Classification of electrically-evoked potentials in the parkinsonian subthalamic nucleus region. Sci Rep 13, 2685 (2023).
To cite this abstract in AMA style:
B. Mohanty, N. Perera, K. O'Neill Iii, S. Alberico, M. Hill, D. Bauer, B. Pobiel, J. Froula, D. Darrow, M. Park, J. Wang, L. Johnson, J. Aman, J. Vitek. Low-frequency pallidum evoked potential dynamics as a prospective biomarker for Parkinson’s disease [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/low-frequency-pallidum-evoked-potential-dynamics-as-a-prospective-biomarker-for-parkinsons-disease/. Accessed October 5, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/low-frequency-pallidum-evoked-potential-dynamics-as-a-prospective-biomarker-for-parkinsons-disease/