Infective endocarditis (IE) with embolic stroke represents a devastating complication where infected cardiac valve vegetations fragment and travel through the systemic circulation to occlude cerebral arteries. Vegetations form when turbulent blood flow across damaged or prosthetic valves creates endothelial injury, exposing subendothelial collagen that triggers platelet-fibrin deposition (nonbacterial thrombotic endocarditis/NBTE). During transient bacteremia (dental procedures, IV drug use, invasive procedures, skin infections), bacteria colonize this sterile nidus. Staphylococcus aureus is the most common organism in acute IE (aggressive, rapid destruction, large vegetations — highest embolic risk); viridans group streptococci cause subacute IE (slower course, smaller vegetations). The organisms multiply within the fibrin-platelet matrix, protected from host immune defenses and antibiotics, forming friable vegetations. Embolic events occur in 20-50% of IE cases; the brain is the most common embolic target. Cerebral embolism causes ischemic stroke (sudden focal neurological deficit). Hemorrhagic transformation may follow from reperfusion injury or septic arteritis weakening the vessel wall. Mycotic aneurysms (infected arterial wall weakening) can rupture, causing subarachnoid or intracerebral hemorrhage. Modified Duke criteria are used for diagnosis: 2 major criteria (positive blood cultures with typical...