The Second Hospital of Dalian Medical University
The purpose of the clinical trial is to find a treatment for stroke patients with cognitive impairment, and the main questions it aims to answer are: * \[Search for effective treatments of cognitive impairment after stroke\] * \[explore the relationship between BDNF level and cognitive function\] Participants will receive conventional treatment, tDCS treatment, .And then compare cognitive function and BDNF level
• (1)Stroke patients with CT or MRI imaging evidence, among which ischemic stroke met the diagnostic criteria of Chinese Guidelines for the Diagnosis and Treatment of Acute Ischemic Stroke 2018, and cerebral hemorrhage diseases met the diagnostic criteria of Chinese Guidelines for the Diagnosis and Treatment of Cerebral hemorrhage 2019; (2) There are symptoms related to cognitive dysfunction; Cognitive dysfunction was assessed by rehabilitation physicians. According to the MoCA evaluation standard,MoCA score ≤26 points; according to the MMSE evaluation standard, illiteracy score ≤17 points; primary school education level ≤20 points; secondary school education (including secondary school) level ≤22 points; college education (including junior college) level ≤23 points; (3)Age range 40-80 years old; (4) no obvious aphasia, speech expression and attention can cooperate with the completion of evaluation and treatment; (5)The patient or the patient's family members read and agree to sign the informed consent.