Effect of tDCS Concurrent With VR-based Robot on Hemiplegic Upper Limb Function After Ischemic Stroke: A Randomized Controlled Study

Abstract

Abstract Background Upper limb hemiplegia faces the challenge of slow and difficult recovery. A “closed-loop method” based on brain plasticity has been proposed, combining central and peripheral interventions to enhance the upper limb function. Based on the theory, we aimed to investigate the effect of transcranial direct current stimulation (tDCS) concurrent with virtual reality (VR)-based robot intervention on the enhancement of upper limb function recovery and the change of cortical excitability. Methods In this single-blinded, randomized, controlled clinical trial, 40 patients with subacute stroke were recruited and randomized to experimental (tDCS concurrent with VR-based robotic intervention) and control (sham tDCS concurrent with VR-based robotic intervention) groups. All patients received 15 sessions for 20 minutes per day. Outcome measures included the Fugl-Meyer Assessment Upper Limb Scale (FMA-UL), the Action Research Arm Test (ARAT), and activities of daily life (ADL). Results Thirty-four patients completed functional near-infrared spectroscopy (fNIRS) examinations. Both groups showed meaningful enhancements in FMA-UL, ARAT, and modified Barthel index (MBI) scores following the training. When the two groups were compared, the FMA-UL and ARAT scores showed greater improvement in the examination group compared to the control group, but the MBI difference was not statistically significant. An analysis of fNIRS results revealed that the activation of the ipsilesional primary motor cortex (iM1) and contralesional prefrontal cortex (cPFC) increased after training in the experimental group, while it decreased in the control group. The activation of iM1 and cPFC in the experimental group was significantly higher than that in the control group. Conclusions Compared with the control group, tDCS concurrent with VR-based robot intervention can effectively enhance upper limb function and promote activation of iM1 and cPFC in subacute patients with stroke. However, there was no obvious advantage in improving ADL. Trial registration: The study was registered in the Chinese Clinical Trial Registration Center (ChiCTR2100047442) on June 18, 2021.