Altered Pallidocortical Low-Beta Oscillations During Self-Initiated Movements in Parkinson Disease

Abstract

Background Parkinson disease (PD) patients have difficulty with self-initiated (SI) movements, presumably related to basal ganglia thalamocortical (BGTC) circuit dysfunction, while showing less impairment with externally cued (EC) movements. Objectives We investigate the role of BGTC in movement initiation and the neural underpinning of impaired SI compared to EC movements in PD using multifocal intracranial recordings and correlating signals with symptom severity. Methods We compared time-resolved neural activities within and between globus pallidus internus (GPi) and motor cortex during between SI and EC movements recorded invasively in 13 PD patients undergoing deep brain stimulation implantation. We compared cortical (but not subcortical) dynamics with those recorded in 10 essential tremor (ET) patients, who do not have impairments in movement initiation. Results SI movements in PD are associated with greater low-beta (13–20 Hz) power suppression during pre-movement period in GPi and motor cortex compared to EC movements in PD and compared to SI movements in ET (motor cortex only). SI movements in PD are uniquely associated with significant low-beta pallidocortical coherence suppression during movement execution that correlates with bradykinesia severity. In ET, motor cortex neural dynamics during EC movements do not significantly differ from that observed in PD and do not significantly differ between SI and EC movements. Conclusion These findings implicate low beta BGTC oscillations in impaired SI movements in PD. These results provide a physiological basis for the strategy of using EC movements in PD, circumventing diseased neural circuits associated with SI movements and instead engaging circuits that function similarly to those without PD.

Attenuation of neural responses in subthalamic nucleus during internally guided voluntary movements in Parkinson’s disease

“…Significant beta desynchronization was found not only in the STN but also in the globus pallidus and motor cortex of PD patients when performing ET and IG movements (Choi et al, 2020). This is consistent with the thesis that changes in beta activity in the BGTM network supporting movements are a prerequisite for normal motor control (van Wijk et al, 2017).…”

Large-scale frontoparietal theta, alpha, and beta phase synchronization: A set of EEG differential characteristics for freezing of gait in Parkinson’s disease?

“…Exaggerated low-beta power in global as well as local oscillatory synchronies in the beta frequency band within BG-Thalamo-Cortical network is a hallmark of PD pathophysiology ( Choi et al, 2020 ), especially in PD with FOG. There is also evidence that there is a significant correlation between alpha and beta power spectrum and L-dopa intake, implying the role of dopaminergic mechanisms in the modulation of alpha and beta oscillations ( Melgari et al, 2014 ).…”

Irregularity of instantaneous gamma frequency in the motor control network characterize visuomotor and proprioceptive information processing

“…To do this, we combined the pre-and post-operative CT scans and co-registered to the preoperative structural MRI, along with the lateral fluoroscopy image that showed the EcoG strip and implanted DBS leads. This method is adopted from [31], and details are further elaborated in our prior publications [32,33]. Based on the visualized localization (figure 1(B)), we identified the two closest channels overlaying the three cortical areas-M1, S1, and PPC-and bipolarreferenced those signals to capture the local activity in these regions.…”