Increased both cortical activation and functional connectivity after transcranial direct current stimulation in patients with post-stroke: A functional near-infrared spectroscopy study

Abstract

BackgroundPrevious studies have shown that cognitive impairment is common after stroke. Transcranial direct current stimulation (tDCS) is a promising tool for rehabilitating cognitive impairment. This study aimed to investigate the effects of tDCS on the rehabilitation of cognitive impairment in patients with stroke.MethodsTwenty-two mild–moderate post-stroke patients with cognitive impairments were treated with 14 tDCS sessions. A total of 14 healthy individuals were included in the control group. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). Cortical activation was assessed using functional near-infrared spectroscopy (fNIRS) during the verbal fluency task (VFT).ResultsThe cognitive function of patients with stroke, as assessed by the MMSE and MoCA scores, was lower than that of healthy individuals but improved after tDCS. The cortical activation of patients with stroke was lower than that of healthy individuals in the left superior temporal cortex (lSTC), right superior temporal cortex (rSTC), right dorsolateral prefrontal cortex (rDLPFC), right ventrolateral prefrontal cortex (rVLPFC), and left ventrolateral prefrontal cortex (lVLPFC) cortical regions. Cortical activation increased in the lSTC cortex after tDCS. The functional connectivity (FC) between the cerebral hemispheres of patients with stroke was lower than that of healthy individuals but increased after tDCS.ConclusionThe cognitive and brain functions of patients with mild-to-moderate stroke were damaged but recovered to a degree after tDCS. Increased cortical activation and increased FC between the bilateral cerebral hemispheres measured by fNIRS are promising biomarkers to assess the effectiveness of tDCS in stroke.

Application of Novel Wearable Self-Balancing Exoskeleton Robot Capable for Complete Self-Support in Post-stroke Rehabilitation: A Case Study

“…Brain plasticity plays a crucial role in motor recovery after stroke, involving neuronal reorganization, synaptic plasticity, axonal sprouting, limited neurogenesis, changes in neurotransmitter systems, and structural changes. From a rehabilitation perspective, repeated, high-dose training can help activate brain regions and reorganize networks to improve functional recovery [ 15 , 16 ]. Robots can provide guidance force and weight support [ 17 ] with the exoskeleton device, allowing personalized adjustment training intensity based on the severity of the participants.…”

Effect of hyperbaric oxygen therapy combined with repetitive transcranial magnetic stimulation on vascular cognitive impairment: a randomised controlled trial protocol

“…The increase in HbO 2 is positively correlated with cortical excitability. Yang et al 45 proposed that increased cortical activation between bilateral cerebral hemispheres, as measured by fNIRS, was a promising biomarker for evaluating the effectiveness of neuroregulatory therapy in PSCI. In recent years, some studies have applied fNIRS to obtain the activation state information of different brain functional regions after TMS to further study the mechanism of TMS in different diseases.…”