Biomarkers of Acute Stroke in Clinic

Inclusion Criteria: * Patients \>18 and \< 80 years of age. * Signs and symptoms suggestive of AIS due to cardioembolic, large vessel, or unknown etiology according to TOAST criteria. * Arrival to the ED within 30 hours of symptom onset or last known normal time and clinical evidence suggesting Acute Ischemic Stroke. * Head CT or MRI ruling out other pathology such as vascular malformation, hemorrhage, tumor or abscess which would likely be responsible for presenting neurologic symptoms * Informed consent obtained Exclusion Criteria: * Any central nervous system infection, i.e. meningitis or encephalitis in the past 30 days * Any form of head trauma, stroke or intracranial hemorrhage in the past 30 days * Any history of primary or metastatic brain cancer * Active cancer defined as a diagnosis of cancer, within 6 months before enrollment, any treatment for cancer within the previous 6 months, or recurrent or metastatic cancer. * Autoimmune diseases: such as lupus, rheumatoid arthritis, Crohn's disease, ulcerative colitis * Active chronic infectious diseases (eg. HIV/AIDS, hepatitis C) * Any underlying medical condition which in the opinion of the investigator would prohibit the patient from providing informed consent * Major surgery within three months prior to the index event * Signs and symptoms suggestive of (i) AIS due to small vessel occlusion (lacune) and other known etiology according to TOAST criteria, as well as (ii) stroke mimics, transient ischemic attacks, or tr…