Differential Diagnosis for Basilar Artery Stroke, Wedge Renal Infarct, and Strep Gallolyticus Bacteremia
Single Most Likely Diagnosis
- Endocarditis with Embolic Phenomena: This diagnosis is the most likely due to the presence of Strep gallolyticus bacteremia, which is a known cause of endocarditis, particularly in the context of basilar artery stroke and wedge renal infarct, suggesting embolic events. The normal TTE (transthoracic echocardiogram) does not entirely rule out endocarditis, as the infection can be on the tricuspid valve or the vegetations might be too small to be detected.
Other Likely Diagnoses
- Atrial Fibrillation with Embolism: Although a normal TTE does not show atrial fibrillation at the time of the exam, paroxysmal atrial fibrillation could be a cause of embolic strokes and might not be captured during the TTE. The wedge renal infarct could also be due to an embolic event from the heart.
- Vasculitis (e.g., Giant Cell Arteritis, Polyarteritis Nodosa): Vasculitis could explain both the stroke and the renal infarct due to inflammation of the blood vessels. However, the presence of Strep gallolyticus bacteremia makes this less likely but still a consideration.
- Hypercoagulable State: Conditions such as protein C or S deficiency, antithrombin III deficiency, or factor V Leiden mutation could lead to both arterial and venous thrombosis, potentially explaining the renal and cerebral events.
Do Not Miss Diagnoses
- Dissecting Aortic Aneurysm: Although less likely, a dissecting aortic aneurysm could lead to both stroke (through carotid or vertebral artery involvement) and renal infarction (through involvement of the renal arteries). This diagnosis is critical to consider due to its high mortality rate if not promptly treated.
- Cholesterol Crystal Embolism: This condition, often occurring after invasive vascular procedures, could explain the renal infarct and potentially the stroke if the emboli reach the cerebral circulation.
Rare Diagnoses
- Non-bacterial Thrombotic Endocarditis (NBTE): Also known as marantic endocarditis, this condition involves the formation of sterile vegetations on heart valves, which can embolize. It is often associated with malignancy or sepsis.
- Infective Endocarditis of Unusual Sites (e.g., Pulmonary Valve): While less common, endocarditis can occur on any valve, including the pulmonary valve, and could potentially lead to the described embolic phenomena.
- Paradoxical Embolism: If there's an undiagnosed patent foramen ovale or other right-to-left shunt, it could allow venous thrombi to embolize to the arterial circulation, causing stroke and renal infarct.