Induction and Increase of Cortico-Cortical Reorganisation Post Stroke

Stroke leads to a sudden brain injury with damage in neuronal networks. Fundamental for recovery of function after stroke is an adaptive reorganization of surviving cerebral networks by mechanisms of neural plasticity. These include structural remodeling of peri-lesional brain tissue and reorganization of large-scale brain networks, thereby compensating for the structural damage and regaining lost sensation, motion and cognition. Results from basic neuroscience suggest that cortical reorganization after stroke is based on activity-dependent rewiring and synaptic plasticity. Functional neuroimaging and electrophysiological techniques have allowed the investigation of cortical reorganization after stroke also in humans in vivo. In addition, non-invasive brain stimulation techniques like transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS) can directly interfere with mechanisms of synaptic plasticity. Thus, integrating knowledge gained in recent years about the complex and dynamic cerebral processes underlying recovery of function after stroke with interventional approaches using non-invasive brain stimulation can open the opportunity to individually facilitate adaptive cortical reorganization and, thereby, promote recovery. This article reviews key findings from the neural mechanisms of recovery of function after stroke to the first promising clinical studies promoting cortical reorganization in humans.