Towards Targeted Brain Stimulation in Stroke: Connectivity asa Biomarker of Response

摘要

Stroke is a leading cause of adult disability. New treatments capable of assisting recovery hold significant potential to improve quality of life for many stroke survivors. Transcranial direct current stimulation is one technique that has received much attention due to its potential to promote neuroplasticity and enhance recovery. However, current evidence suggests this is not a one-size-fits-all treatment with indication that responses are highly variable. Using electroencephalography, Hordacre et al recently demonstrated that connectivity between the ipsilesional motor cortex, ipsilesional parietal cortex, and contralesional frontotemporal cortex was a strong predictor of the neurophysiological response to anodal transcranial direct current stimulation applied to the ipsilesional motor cortex in people with chronic ischemic stroke. Based on this outcome, we discuss the potential for connectivity to be used as a biomarker to target transcranial direct current stimulation. This includes identification of a connectivity threshold which could be used to select stroke survivors who are likely to respond to this potentially beneficialneuromodulatory treatment. Furthermore, we discuss treatmentapproaches for those identified as unlikely to benefit fromipsilesional anodal transcranial direct current stimulation based onconnectivity profile. This represents an important progression towardstargeting transcranial direct current stimulation for best treatmentoutcome based on individual connectivity characteristics.