Spontaneous sensorimotor cortical activity is suppressed by deep brain stimulation in patients with advanced Parkinson’s disease

Abstract

Advanced Parkinson's disease (PD) is characterized by an excessive oscillatory beta band activity in the subthalamic nucleus (STN). Deep brain stimulation (DBS) of STN alleviates motor symptoms in PD and suppresses the STN beta band activity. The effect of DBS on cortical sensorimotor activity is more ambiguous; both increases and decreases of beta band activity have been reported. Non-invasive studies with simultaneous DBS are problematic due to DBS-induced artifacts. We recorded magnetoencephalography (MEG) from 16 advanced PD patients with and without STN DBS during rest and wrist extension. The strong magnetic artifacts related to stimulation were removed by temporal signal space separation. MEG oscillatory activity at 5-25 Hz was suppressed during DBS in a widespread frontoparietal region, including the sensorimotor cortex identified by the cortico-muscular coherence. The strength of suppression did not correlate with clinical improvement. Our results indicate that alpha and beta band oscillations are suppressed at the frontoparietal cortex by STN DBS in PD.

A systematic review of MEG‐based studies in Parkinson's disease: The motor system and beyond

“…DRT significantly increased cortical motor beta band power, thus having a normalizing effect (Heinrichs‐Graham, Kurz, et al, ). In contrast, STN‐DBS lowered alpha and low‐beta band power in the sensorimotor cortex in two studies (both a sensor‐space and a source‐space study) during eyes‐open, resting‐state (Abbasi et al, ; Luoma et al, ). However, no correlation with motor improvement has been observed.…”

“…Posterior cortical dysfunction seems to play a crucial role here (Boon et al, ; Olde Dubbelink, Hillebrand, Twisk, et al, ; Stoffers et al, ). Treatments such as DRT and rivastigmine generally normalized disrupted neurophysiological characteristics in both research fields, although many discrepancies exist, for example the increase in cortical motor beta power upon DRT (Heinrichs‐Graham, Kurz, et al, ), versus the decrease observed upon DBS (Abbasi et al, ; Luoma et al, ), or the differential effect of DRT on whole‐brain functional connectivity (Cao et al, ; Stoffers, Bosboom, Wolters, et al, ). Potential explanations for these discrepancies include methodological differences and differences in the underlying neurophysiological characteristics between PD patients (Figures and ).…”

“…Studies in later-stage PD patients found that beta band power in cortical motor regions was lower during the resting state compared to con- Flowchart for inclusion of studies Luoma et al, 2018). However, no correlation with motor improvement has been observed.…”

“…In studies that estimated motor CMC, beta band power in cortical motor regions (and possibly also global beta band power) also differed between PD patients and controls and could therefore have impacted the CMC findings Salenius et al, 2002). In addition, the occipital dominant alpha band rhythm, mainly present when the eyes are closed, may dilute differences observed in the motor network studies (Luoma et al, 2018). 4.2 | Whole-brain research: Toward a more focused approach…”

Reduction of spontaneous cortical beta bursts in Parkinson’s disease is linked to symptom severity

“…Similarly, Parkinson's patients treated with electrical deep brain 26 stimulation (DBS) showed an increase in cortical sensorimotor beta power following DBS 27 compared to off treatment (Airaksinen et al, 2012;Cao et al, 2017). However, other studies 28 have reported that DBS leads to a broader suppression of 5-25 Hz power in frontal and 29 sensorimotor cortex (Abbasi et al, 2018;Luoma et al, 2018). 30…”