To study safety and feasibility of mild therapeutic hypothermia after successful recanalization by mechanical endovascular treatment in patients with acute ischemic stroke and proximal arterial occlusion.

The current clinical trial is an investigator-initiated one, and it is conducted under the multi-center, randomized, open-label, prospective design. The subjects meeting inclusion/exclusion criteria will be assigned to the treatment group or the control group. The randomization ratio is 1:1. The subjects of the treatment group will receive a 2-day hypothermia therapy followed by the process of recovery of temperature within 30 hours (the recovery phase). After 3 months of the onset of symptoms, mRS scores are measured. This is followed by the closure of the clinical trial.

Inclusion Criteria:

1. Subjects who submitted a written informed consent prior to the participation in the current clinical trial (If the subjects have conditions that they cannot decide on study participation according to their own will, they would participate in the study after their legal representatives submitted a written informed consent form. During the period of study participation, if patients' medical conditions are improved, the written informed consent should be submitted again.)
2. Patients with ischemic stroke attributed to carotid artery or middle cerebral artery occlusion achieved successful recanalization (TICI 2b or 3) immediately after endovascular treatment within 8 hours of symptom onset: Onset time was defined as the time when patients were lastly seen normal.
3. Patients of both sexes aged between 18 and 80 years old
4. NIHSS scores of 6-25 points at screening
5. mRS 1 prior to the onset of disease, with proximal cerebral artery occlusion (e.g., those with middle cerebral or internal carotid artery)

Exclusion Criteria:

1. No evaluation for cranial artery before endovascular treatment
2. Patient with emergent stenting insertion in intracranial or extracranial artery
3. Transient ischemic attack or lacunar infarction
4. Platelet counts < 75,000/mm3
5. coagulopathy (INR spontaneously >1.5)
6. Hemodynamic instability
7. acute myocardial infarction, acute unstable angina or severe cardiac failure (NYHA classification ≥III)
8. Sepsis
9. Pregnant or breastfeeding women
10. Premorbid modified Rankin Scale Scores of > 2 points
11. Hypersensitivity or allergy to following: buspirone, dexmedetomidine, meperidine
12. Intracranial hemorrhage or hemorrhagic transformation in initial CT scan
13. Brain tumor or CNS infection
14. Patients who participated in other clinical trials within 3 months
15. Life expectancy within 1 year