BDNF and Stroke: Plasma biomarkers of brain injury, such as neuron-specific enolase (NSE), protein S100 (pS100), brain-derived neurotrophic factor (BDNF), and glial fibrillary acidic protein (GFAP) from neurons, astrocytes, and axons have been studied in the last years with clinical applicability in traumatic brain injury, stroke, hypoxic–ischemic encephalopathy (HIE) and cardiopulmonary bypass (CPB) [10,11,12,13].