Altered Cognitive Networks Connectivity in Parkinson's Disease During the Microlesion Period After Deep Brain Stimulation

Abstract

Aims: Cognitive functions are reduced in Parkinson's disease (PD) patients after deep brain stimulation (DBS) surgery. However, the underlying mechanisms remain unclear. The current study attempted to elucidate whether DBS alters the functional connectivity (FC) pattern of cognitive networks in PD patients.

Methods: The study obtained fMRI and cognitive scale data from 37 PD patients before and after the DBS surgery. Seed-based FC analysis helped demonstrate the FC changes of the default mode network (DMN), executive control network (ECN), and dorsal attention network (DAN).

Results: PD patients indicated significant network connectivity decline in DMN [such as in right precuneus, left angular gyrus, and left middle frontal gyrus (MFG)], ECN [such as in left inferior parietal gyrus, left MFG, and left supplementary motor area (SMA)], and DAN [such as in left inferior frontal gyrus and left MFG] post-DBS surgery. The phonemic fluency score was positively associated with the FC value of the right precuneus and left angular gyrus in DMN before DBS.

Conclusion: The general reduction in FC in the major cognitive networks after DBS surgery depicted the presence of the corresponding network reorganization. Further research can help explore the mechanism of impaired cognitive function post-DBS.

Keywords: Parkinson's disease; deep brain stimulation; functional magnetic resonance imaging; microlesion effect; resting‐state functional connectivity; verbal fluency.