Inclusion Criteria:  SAH patients with modified Fisher Scale 3-4.  Exclusion Criteria:  Patients with history of CNS disease (e.g., stroke, traumatic brain injury, CNS infection) or accompanied by serious comorbidities before SAH onset (e.g., severe coagulation disorders, malignant tumor, uncontrollable heart disease, and hypertension) or other organ dysfunctions within 6 months were excluded from the study