Brain plasticity following MI-BCI training combined with tDCS in a randomized trial in chronic subcortical stroke subjects: a preliminary study

• Published in: Scientific reports Vol. 7; no. 1; pp. 9222 - 12
• Main Authors: Hong, Xin, Lu, Zhong Kang, Teh, Irvin, Nasrallah, Fatima Ali, Teo, Wei Peng, Ang, Kai Keng, Phua, Kok Soon, Guan, Cuntai, Chew, Effie, Chuang, Kai-Hsiang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23.08.2017; Nature Publishing Group; Nature Portfolio
• Subjects: 59/57; 631/378/1689/534; 692/617/375/534; Blood flow; Brain; Cerebral blood flow; Cerebral hemispheres; Computer applications; Corpus callosum; Electrical stimulation of the brain; ESB; Excitability; Humanities and Social Sciences; Implants; Magnetic fields; Magnetic resonance imaging; Mental task performance; Motor task performance; multidisciplinary; Neural networks; Neuroplasticity; Perfusion; Pyramidal tracts; Quality control; Rehabilitation; Science; Science (multidisciplinary); Sensorimotor system; Stroke; Substantia alba
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-08928-5

Brain-computer interface-assisted motor imagery (MI-BCI) or transcranial direct current stimulation (tDCS) has been used in stroke rehabilitation, though their combinatory effect is unknown. We investigated brain plasticity following a combined MI-BCI and tDCS intervention in chronic subcortical stroke patients with unilateral upper limb disability. Nineteen patients were randomized into tDCS and sham-tDCS groups. Diffusion and perfusion MRI, and transcranial magnetic stimulation were used to study structural connectivity, cerebral blood flow (CBF), and corticospinal excitability, respectively, before and 4 weeks after the 2-week intervention. After quality control, thirteen subjects were included in the CBF analysis. Eleven healthy controls underwent 2 sessions of MRI for reproducibility study. Whereas motor performance showed comparable improvement, long-lasting neuroplasticity can only be detected in the tDCS group, where white matter integrity in the ipsilesional corticospinal tract and bilateral corpus callosum was increased but sensorimotor CBF was decreased, particularly in the ipsilesional side. CBF change in the bilateral parietal cortices also correlated with motor function improvement, consistent with the increased white matter integrity in the corpus callosum connecting these regions, suggesting an involvement of interhemispheric interaction. The preliminary results indicate that tDCS may facilitate neuroplasticity and suggest the potential for refining rehabilitation strategies for stroke patients.