Identification of microRNAs Involved in Cerebral Collateral Regulation

Patients \>18 years of age presenting to Ohio State Wexner Medical Center Emergency department with stroke symptoms, within 6 hours of last know well and found to have acute anterior circulation large vessel occlusion (LVO) will be included in this study. The purpose of this study is to evaluate the differential expression of exosomal microRNAs in patients with stroke due to acute LVO as compared to healthy controls. In addition, the investigators will also evaluate the differential expression of exosomal microRNA in patients with good vs poor collateral grade.

Inclusion criteria: 1. Age 18 years or older. 2. Diagnosis of Acute Ischemic Stroke secondary to LVO 3. LVO from presumed embolic source (\50% stenosis of internal carotid artery 2. \>50% stenosis of bilateral vertebral arteries. 3. Patients with moderate to severe intracranial atherosclerotic disease as seen in CTA of head and neck. 4. Known moderate to severe PVD or symptomatic CAD 5. Past medical history of stent or coronary artery bypass surgery 6. Prisoners 7. Pregnant women 8. Previous stroke within 30 days 9. Intracranial vascular malformation or evidence of moya-moya disease 10. Serious advanced or terminal illness per judgment of the investigator with life expectancy \