Altered Regional Homogeneity and Functional Connectivity during Microlesion Period after Deep Brain Stimulation in Parkinson’s Disease

Abstract

Background. Patients with Parkinson’s disease (PD) undergoing deep brain electrode implantation experience a temporary improvement in motor symptoms before the electrical stimulation begins. We usually call this the microlesion effect (MLE), but the mechanism behind it is not clear. Purpose. This study aimed to assess the alterations in brain functions at the regional and whole-brain levels, using regional homogeneity (ReHo) and functional connectivity (FC), during the postoperative microlesion period after deep brain stimulation (DBS) in PD patients. Method. Resting-state functional MRI data were collected from 27 PD patients before and after the first day of DBS and 12 healthy controls (HCs) in this study. The ReHo in combination with FC analysis was used to investigate the alterations of regional brain activity in all the subjects. Results. There were increased ReHo in the basal ganglia-thalamocortical circuit (left supplementary motor area and bilateral paracentral lobule), whereas decreased ReHo in the default mode network (DMN) (left angular gyrus, bilateral precuneus), prefrontal cortex (bilateral middle frontal gyrus), and the cerebello-thalamocortical (CTC) circuit (Cerebellum_crus2/1_L) after DBS. In addition, we also found abnormal FC in the lingual gyrus, cerebellum, and DMN. Conclusion. Microlesion of the thalamus caused by electrode implantation can alter the activity of the basal ganglia-thalamocortical circuit, prefrontal cortex, DMN, and CTC circuit and induce abnormal FC in the lingual gyrus, cerebellum, prefrontal cortex, and DMN among PD patients. The findings of this study contribute to the understanding of the mechanism of MLE.

Reorganization of motor network in patients with Parkinson's disease after deep brain stimulation

“…30,[39][40][41] Wu et al 41 observed that PD patients had decreased regional homogeneity (ReHo) in the SMA compared to healthy controls. In a recent study, the ReHo of SMA was elevated during MLE after DBS surgery, 16 suggesting that DBS relatively normalized SMA activity. The prefrontal cortex helps plan, regulate, and control psychological activities.…”

“…However, the sample size limited the result accuracy of the results 8 . Our previous work has demonstrated alterations in brain activation in motor‐related brain areas, such as the precentral gyrus and supplementary motor area (SMA), during microlesion after DBS 15,16 . However, they are yet to explore the change in the motor network.…”

Inherent regional brain activity changes in male obstructive sleep apnea with mild cognitive impairment: A resting-state magnetic resonance study

“…Regional homogeneity (Reho) is a data-driven local measure of spontaneous neural activity that does not require the onset time of stimulation or prior knowledge and has good test–retest reliability ( Xia et al, 2018 ). Functional connectivity (FC) is an fMRI data processing method used to explore the functional interactions between anatomically separated brain regions ( Luo et al, 2021 ). Reho and FC are considered to be complementary in examining the synchronization of local and remote brain activity ( Sun et al, 2018 ),and the simple computations and reliable representations involved have led to their use in exploring brain diseases with underlying functional alterations, such as epilepsy ( Liu et al, 2021 ), Alzheimer’s ( Ibrahim et al, 2021 ), and depression ( Chen et al, 2021 ).…”