BDNF and Aphasia: It is well known that BDNF is essentially a protein, which plays an important role in the growth and differentiation of nerve cells, and can repair damaged nerve cells, thereby improving advanced cognitive functions (learning, memory, etc.)(Asadi et al., 2018; Huey Fremont et al., 2020), especially, it plays an important role in mediating the neural plasticity process of language function recovery in patients with aphasia after stroke (Di Pino et al., 2016).