STN-DBS Induces Acute Changes in β-Band Cortical Functional Connectivity in Patients with Parkinson's Disease

Subthalamic nucleus deep-brain stimulation (STN-DBS), in addition to a rapid improvement of Parkinson's disease (PD) motor symptoms, can exert fast, local, neuromodulator activity, reducing beta-synchronous oscillations between STN and the motor cortex with possible antikinetic features. However, STN-DBS modulation of beta-band synchronization in extramotor cortical areas has been scarcely explored. For this aim, we investigated DBS-induced short-term effects on EEG-based cortical functional connectivity (FC) in beta bands in six PD patients who underwent STN-DBS within the past year. A 10 min, 64-channel EEG recording was performed twice: in DBS-OFF and 60 min after DBS activation. Seven age-matched controls performed EEG recordings as the control group. A source-reconstruction method was used to identify brain-region activity. The FC was calculated using a weighted phase-lag index in beta bands. Group comparisons were made using the Wilcoxon test. The PD patients showed a widespread cortical hyperconnectivity in beta bands in both DBS-OFF and -ON states compared to the controls. Moreover, switching on STN-DBS determined an acute reduction in beta FC, primarily involving corticocortical links of frontal, sensorimotor and limbic lobes. We hypothesize that an increase in beta-band connectivity in PD is a widespread cortical phenomenon and that STN-DBS could quickly reduce it in the cortical regions primarily involved in basal ganglia-cortical circuits.

Automated summary

In this study, the short-term effects of subthalamic nucleus deep-brain stimulation (STN-DBS) on beta-band cortical functional connectivity (FC) were investigated in Parkinson's disease (PD) patients. The results showed that PD patients exhibited widespread cortical hyperconnectivity in beta bands, and STN-DBS could acutely reduce beta FC primarily in cortical regions involved in basal ganglia-cortical circuits.