BDNF and Cognitive impairment: Evidence shows that the mortality rate is substantially higher in stroke patients with cognitive impairment than those without.16 The pathogenesis appears to involve: Structural damage to the brain tissue; Neurotransmitter systems with abnormal changes in acetylcholine (ACh), arterenol, dopamine, enteramine, gamma-aminobutyric acid (GABA), glutamate, and brain-derived neurotrophic factor; Inflammatory responsefree radical reactions.17