Transcranial Direct Current Stimulation Reduces Secondary White-Matter Degradation After Stroke

Abstract

Recent studies demonstrated that stroke patients with large lesion to the cortico-spinal tract (CST) show secondary degradation of ipsilesional white matter tracts and poor motor recovery (POOR) in the subacute period. This suggests that white matter preservation might be an interesting target for this group of patients and might help improve motor outcome. Non-invasive brain stimulation (NIBS) can boost motor function in stroke patients, but we lack information on its impact on white matter microstructure. Therefore, we conducted a randomized controlled trial comparing the effects of cathodal transcranial direct current stimulation (ca-tDCS), continuous theta burst stimulation (cTBS), or sham stimulation on white matter degradation and motor improvement, as measured with Diffusion Tensor Imaging (DTI) and standardised motor assessments. Results showed preserved structural connectivity after ca-tDCS compared with the other experimental groups in POOR patients. This correlated with better clinical recovery.