Brain Injury, Neural Plasticity, and Neuromodulation

Brain injury stemming from any cause represents a main reason of death and disability worldwide, leading to high burden for both the patient and caregivers. Consequently, rehabilitation strategies strive to achieve higher functional goals to improve brain plasticity mechanisms (which are essential to motor function recovery), including neuromodulation techniques, such as transcranial electric stimulation and transcranial magnetic stimulation. Both such approaches can induce short- and long-term changes of synaptic excitability to restore the impaired functions in stroke patients. This chapter provides an overview of the neuroplasticity mechanisms related to brain injury and neuromodulation. Generally speaking, rehabilitation strategies strengthen the excitation and synchronization of the neural activity following a brain injury. As a result, the neuroplastic effect can lead to better functional connection in the brain network in assisting motor function recovery. Although much progress has been made, more effort is required to clarify the pathways of synaptic plasticity in the whole brain network following neuromodulation after brain damage, and investigation of the different roles of distinctive cell populations in neural plasticity enhancement. Furthermore, standard protocols in neuromodulation remain to be better established to ultimately optimize their clinical efficacy.