Intra-Arterial Magnesium Therapy After Mechanical Thrombectomy in Acute Ischemic Stroke

Inclusion Criteria: 1. Patient with acute cerebral ischemia due to ICA or MCA occlusion 2. Major neurologic deficits: 6≤NIHSS≤20, 3. Premorbid mRS 0 or 1, or 2 4. Patient's clinical attending physician plans MT procedure as part of routine clinical care, 5. undergo MT with a TICI 2a or better recanalization, 6. Signed informed consent. Exclusion Criteria: 1. Positive pregnancy test; 2. those undergoing MT with a TICI \<2a revascularization; 3. tandem occlusion of the cervical common or internal carotid artery; and 4. subjects on therapeutic anticoagulation, as it is a relative contraindication to MT, and could be a confounding variable predisposing to intracranial hemorrhage including coagulation disorders, systematic hemorrhagic tendency, thrombocytopenia \<80000/mm3; 5. Second or third-degree heart block without a pacemaker in place, 6. Technical inability to navigate micro-catheter to target clot, 7. Patient already enrolled in another experimental treatment trial. Exclusion criteria 1-3 are all contraindications to magnesium therapy, 8. mRS\>2 caused by a history of prior stroke, 9. Severe hepatic dysfunction, severe renal dysfunction (\<30 mL/min), increase in ALT or AST (more than 2 times of upper limit of normal value), increase in serum creatinine (more than 1.5 times of upper limit of normal value) or requiring dialysis; 10. Unsuitable for this clinical study assessed by researcher. Subjects will not be excluded if they received IV t-PA as standard of care. 11. patient is on neuromuscular blocking agents including depolarizing (succinylcholine) and nondepolarizing subtypes (rocuronium, vecuronium, etc); 12. patient is taking any form of CNS depressant including barbiturates, narcotics, outside the setting of anesthesia or ICU sedation 13. patients taking digoxin or other cardiac glycoside