The present study is an investigator initiated, single-centre, prospective, proof-of-concept cohort study aiming to enroll 44 patients with acute middle cerebral artery (MCA) ischemic stroke, involving the right (n=22) and left (n=22) MCA territories and 24 control patients with acute focal neurological symptoms but no evidence of acute brain infarct on DWI-MRI.

The present study is an investigator-initiated, single-center, prospective cohort study. The study aims to enroll 44 patients with acute/subacute middle cerebral artery (MCA) ischemic stroke. The investigators will compare inflammatory markers among 44 patients with MCA ischemic stroke within 10 days post-stroke vs. 60±15 days post-stroke. Other measures to be determined at both time points include B-Type Natriuretic Peptide and systemic inflammatory markers.

Inclusion Criteria:

• Acute ischemic stroke in the right or left MCA territory. Acute ischemic stroke is defined as acute onset focal symptoms matching an acute brain infarct documented on Head computed tomography or diffusion-weighted imaging (DWI) MRI of the brain showing restricted diffusion.

Exclusion Criteria:

• History of known atrial fibrillation, prior myocardial infarction, coronary artery disease, heart failure, prior cardiovascular surgery or percutaneous intervention.
• Previous stroke (occurred within 3 months before the index event)
• Impaired renal function defined as a creatinine clearance <97 mL/min in men or <88 mL/min in women, according to the Cockcroft formula.
• hs-TnT >100 on routine acute stroke baseline bloodwork upon admission.
• Clinically or neurologically unstable patients as per the treating physician.
• Ongoing infection or recent infection within the previous 3 months
• Surgery within 3 months before the stroke
• Concurrent and active inflammatory conditions (connective tissue diseases, rheumatological disease, etc.) or use of anti-inflammatory medications
• Pregnancy, Stage IV renal insufficiency, eGFR <30, and any other contraindications to the use of gadolinium.
• Stroke with symptomatic hemorrhagic transformation
• Subjects will be excluded if they fail the LHSC standard MRI screening questionnaire (cardiac pacemakers/wires, aneurysm clips, shunt/surgical clips, shrapnel/bullets, dentures or metal braces, intra-uterine devices, heart valves, ear implants, prostheses, medication patches such as Nicoderm, Habitrol, or Transderm-Nitro, claustrophobia, history of a head or eye injury involving metal fragments.

The investigators will include 44 patients with right (n=22) and left (n=22) MCA ischemic stroke. The investigators aim to include at least 50% of female patients. The investigators will include 24 participants in a control group. Participants in the control group will be patients presenting with acute stroke symptoms but no evidence of acute brain infarction on DWI-MRI imaging. Participants will be divided by sex: the investigators aim to enroll 12 female and 12 male participants. The investigators will aim to enroll participants within the same age range as the stroke participants.