title: Conditional Granger Causality Analysis of Effective Connectivity during Motor Imagery and Motor Execution in Stroke Patients.
abstract: Aims. Motor imagery has emerged as a promising technique for the improvement of motor function following stroke, but the mechanism of functional network reorganization in patients during this process remains unclear. The aim of this study is to evaluate the cortical motor network patterns of effective connectivity in stroke patients. Methods. Ten stroke patients with right hand hemiplegia and ten normal control subjects were recruited. We applied conditional Granger causality analysis (CGCA) to explore and compare the functional connectivity between motor execution and motor imagery. Results. Compared with the normal controls, the patient group showed lower effective connectivity to the primary motor cortex (M1), the premotor cortex (PMC), and the supplementary motor area (SMA) in the damaged hemisphere but stronger effective connectivity to the ipsilesional PMC and M1 in the intact hemisphere during motor execution. There were tighter connections in the cortical motor network in the patients than in the controls during motor imagery, and the patients showed more effective connectivity in the intact hemisphere. Conclusions. The increase in effective connectivity suggests that motor imagery enhances core corticocortical interactions, promotes internal interaction in damaged hemispheres in stroke patients, and may facilitate recovery of motor function.
authors.affiliation: Department of Medical Image, College of Biomedical Engineering, Third Military Medical University, No. 30, Gaotanyan Street, Shapingba District, Chongqing 400038, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Medical Image, College of Biomedical Engineering, Third Military Medical University, No. 30, Gaotanyan Street, Shapingba District, Chongqing 400038, China.
authors.forename: Jingna
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Medical Image, College of Biomedical Engineering, Third Military Medical University, No. 30, Gaotanyan Street, Shapingba District, Chongqing 400038, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Rehabilitation, Southwest Hospital, Third Military Medical University, No. 30, Gaotanyan Street, Shapingba District, Chongqing 400038, China.
authors.forename: Rubing
authors.initials: R
authors.lastname: Yan
authors.affiliation: Department of Rehabilitation, Southwest Hospital, Third Military Medical University, No. 30, Gaotanyan Street, Shapingba District, Chongqing 400038, China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Medical Image, College of Biomedical Engineering, Third Military Medical University, No. 30, Gaotanyan Street, Shapingba District, Chongqing 400038, China.
authors.forename: Mingguo
authors.initials: M
authors.lastname: Qiu
mesh_terms: D063132:Connectome / Q000379:methods*; D003627:Data Interpretation, Statistical; D004569:Electroencephalography / Q000379:methods; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D007092:Imagination; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009068:Movement; D009434:Neural Pathways / Q000503:physiopathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000503:physiopathology*