Determinants of Incident Stroke Cognitive Outcomes and Vascular Effects on RecoverY

Inclusion Criteria: 1. Age ≥18 years 2. Admitted to the enrolling clinical performance site (CPS) hospital with a diagnosis of acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), or aneurysmal subarachnoid hemorrhage (aSAH) 3. Radiographic confirmatory evidence of: (1) AIS (based on a focal area of restricted diffusion on MRI), (2) non-traumatic primary ICH (based on evidence of acute parenchymal hemorrhage on CT or brain MRI) or (3) non-traumatic acute aSAH (based on evidence of subarachnoid hemorrhage on CT or MRI and evidence of aneurysm on CT angiography, MR angiography, or conventional catheter-based angiography) 4. Able to complete baseline visit in person or by phone within 6 weeks of stroke onset 5. Able to provide informed consent by self or proxy 6. Fluent in English or Spanish prior to stroke onset Exclusion Criteria: 1. Documented history of pre-stroke dementia or fails dementia pre-screen 2. Concurrently enrolled into a study that is not approved under the DISCOVERY Co-Enrollment Policy 3. Unable to complete study protocol (advanced directives such as comfort measures only, or inability to complete the study due to severe medical/behavioral co-morbidities), as determined by physician investigator during screening process Additional exclusion criteria for Tier 2 participants: 4. Contraindication to MRI: presence of electrically, magnetically, or mechanically activated implants (such as cardiac pacemakers, cochlear implants, implanted pumps); or metallic clips in the brain Additional exclusion criteria for Tier 3 participants: 5. Age \<50 years 6. Biologically female individuals who are pregnant or seeking to become pregnant 7. Known to have one of the following genetic conditions which can increase the risk of developing cancer: Cowden disease, Lynch syndrome, hypogammaglobulinemia, Wiskott-Aldrich syndrome, Down's syndrome.