Methylprednisolone for Stroke With Large Infarct Core and Post-stroke Lymphocytopenia

Inclusion Criteria: * Age ≥ 18 years. * The time from last known well to randomization was within 24 hours. * Anterior circulation ischemic stroke was preliminarily determined according to clinical symptoms or imaging examination. * Occlusion of the intracranial internal carotid artery, the M1- or M2-segment of the middle cerebral artery by confirmed by CT angiography (CTA), MR angiography (MRA), or digital subtraction angiography (DSA). * Baseline National Institutes of Health Stroke Scale (NIHSS) ≥ 6. * Baseline Alberta Stroke Program Early CT Score (ASPECTS) \< 6 (based on non-contrast CT or MRI) or core infarct volume ≥ 50 ml (based on CTP with rCBF \< 30%). * Planned treatment with endovascular thrombectomy (EVT). * Baseline peripheral blood lymphocyte \< 0.8×10#/L * Informed consent obtained from patients or their legal representatives. Exclusion Criteria: * Intracranial hemorrhage confirmed by cranial CT or MRI. * mRS score \> 2 before the time of last known well. * Pregnant or lactating women. * Allergic to contrast agents or glucocorticoids. * Participating in other clinical trials. * The artery is tortuous so that the thrombectomy device cannot reach the target vessel. * Bleeding history (gastrointestinal and urinary tract bleeding) in recent 1 month. * Chronic hemodialysis and severe renal insufficiency (glomerular filtration rate \< 30 ml/min or serum creatinine \> 220 umol/L \[2.5 mg/ dL\]). * Life expectancy due to any advanced disease \< 6 months. * Follow-up is not expected to be completed. * Intracranial aneurysm and arteriovenous malformation. * Brain tumors with imaging mass effect. * Systemic infectious disease.