Bacteremia is the presence of bacteria in the bloodstream. Bacteremia can be diagnosed by obtaining blood cultures. Circulating bacteria in the bloodstream can infect the heart causing endocarditis. When a patient has bacterial endocarditis, bacterial colonies adhere to heart valves causing vegetations. Whole or partial vegetations can break off and travel to the brain causing a stroke. Bacteremia is treated with intravenous antibiotics. Treatment with intravenous antibiotics can resolve the bacteremia and dramatically reduce the risk of stroke within 1-2 weeks.
Stroke can be either ischemic or hemorrhagic. Ischemic stroke occurs when a blood vessel supplying the brain is obstructed, resulting in permanent neurological damage, commonly referred to as an infarct. Ischemic stroke is frequently caused by an embolism which is abnormal material circulating in the bloodstream. Emboli are commonly composed of clot or atheroma (a fragment of atherosclerotic plaque). In patients with bacterial endocarditis, septic emboli occur when valvular vegetations release material into the bloodstream. This material may travel to the brain and cause an ischemic stroke. The location and size of the stroke determines the patient’s injuries.