Cortico-muscular coherence increases with tremor improvement after deep brain stimulation in Parkinson's disease

Abstract

Deep brain stimulation on the subthalamic nucleus has been used to relieve Parkinsonian motor symptoms. However, the underlying physiological mechanism has not been fully understood. Beta-band cortico-muscular coherence increases when healthy humans perform isometric contraction. We hypothesized that this might be a measure of symptomatic improvement in motor performance after subthalamic nucleus deep brain stimulation. Here, we measured the beta-band cortico-muscular coherence with magnetoencephalography from three Parkinson's disease patients. We then compared the coherence values for stimulator on-state and off-state. We found that when the stimulator is on, the beta cortico-muscular coherence elevates significantly for the tremorous hand compared with that when the stimulator is off. This suggests that deep brain stimulation resulted in better cortico-muscular coordination.

Network effects of deep brain stimulation

“…Specifically, the introduction of temporal signal space separation (tSSS) (Taulu and Simola 2006) and null beamforming (Mohseni et al 2012) has been shown to successfully minimize the effects of the stimulator artifacts, facilitating studies examining the acute effects of DBS by comparing cortical activity during the DBS-on state to the DBS-off state. As a validity study, Park et al (2009) showed increased corticomuscular coherence in the beta band during STN stimulation. Another report supporting MEG feasibility during stimulation comes from the same group that developed the tSSS method for stimulator artifact removal (Airaksinen et al 2011).…”

Rejecting deep brain stimulation artefacts from MEG data using ICA and mutual information

“…The basic idea behind this approach is to separate sources within the brain from sources outside the brain using sensor geometry and Maxwell's equations. So far, tSSS was demonstrated to be suitable for DBS artefact removal during rest, auditory and somatosensory stimulation, as well as in a wrist extension task and changes in cortico-muscular coherence (Mäkelä et al, 2007;Park et al, 2009;Airaksinen et al, 2011Airaksinen et al, , 2012Airaksinen et al, , 2015. Therefore, tSSS has proven to be a powerful tool for MEG-DBS studies.…”

Feature Extraction Methods for Studying Surface Electromyography and Kinematic Measurements in Parkinson’s Disease

“…It has been observed that the medication and DBS may modify the tremor amplitude, regularity and frequency [4,41,42], movement speed [3,8,34,40,44,49,51,52], joint kinetics and muscle activation during movements [55], EMG burst patterns during movement [34,51,52] and the cortico-muscular coherence [25,37]. There is currently a lot of interest for characterizing EMG and kinematic signals of PD patients.…”