title: Mechanisms of neural reorganization in chronic stroke subjects after virtual reality training.
abstract: This study investigates patterns of brain reorganization in chronic stroke subjects after two weeks of robot-assisted arm and hand training in virtual reality (VR). Four subjects were studied with event-related fMRI while doing simple paretic hand finger movements before (double baseline) and after training. Bilateral hand movements were recorded and used to provide real-time feedback to subjects during scanning to eliminate performance confounds on fMRI results. The kinematic parameters of each movement were also used in the general linear model with the BOLD signal to investigate training-induced changes in neuromotor coupling. Univariate analysis showed an increase in BOLD signal in the ipsilesional hemisphere in two subjects and a decrease in activity in the other two subjects. Seed voxel based functional connectivity analysis revealed an increase in connectivity between ipsilesional motor cortex and bilateral sensorimotor cortex during finger movements in all four subjects. Hemispheric laterality index values showed a tendency to decrease reflecting a reduction in the over-dominance of the contralesional hemisphere. The study is novel in terms of 1) tracking finger movement during a motor task in the scanner, 2) monitoring motor performance during the experiment and 3) giving online visual feedback of subjects' movement. This pilot study introduces a novel approach to study neural plasticity by combining measures of regional intensity, interregional interactions (using functional connectivity analysis and hemispheric laterality index), and modulation in the strength of neuromotor coupling.
authors.affiliation: New Jersey Institute of Technology Newark, NJ 07102, USA. shs25@ njit.edu
authors.forename: S
authors.initials: S
authors.lastname: Saleh
authors.forename: H
authors.initials: H
authors.lastname: Bagce
authors.forename: Q
authors.initials: Q
authors.lastname: Qiu
authors.forename: G
authors.initials: G
authors.lastname: Fluet
authors.forename: A
authors.initials: A
authors.lastname: Merians
authors.forename: S
authors.initials: S
authors.lastname: Adamovich
authors.forename: E
authors.initials: E
authors.lastname: Tunik
mesh_terms: D000368:Aged; D002908:Chronic Disease; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology; D009420:Nervous System / Q000503:physiopathology*; D010100:Oxygen / Q000097:blood; D012371:Robotics; D020521:Stroke / Q000097:blood / Q000503:physiopathology*; D013647:Task Performance and Analysis; D014584:User-Computer Interface
chemical_list: D010100:Oxygen