Inclusion Criteria:  Eligible for endovascular thrombectomy to treat acute large vessel occlusion Eligible for angioplasty (microcatheter-based balloon/mechanical and chemical angioplasty) to treat acute cerebral vasospasm after aneurysmal subarachnoid hemorrhage Subjects for whom there is likely to be enough time to obtain meaningful consent from patient or legally-authorized representative  Exclusion Criteria:  Unable to receive a brain MRI scan Known mitochondrial disease Hemodynamically unstable patients in whom standard of care endovascular reperfusion treatment cannot safely be performed or completed