Neurologic complications in infective endocarditis: identification, management, and impact on cardiac surgery

Abstract

Neurologic complications of infective endocarditis (IE) are common and frequently life threatening. Neurologic events are not always obvious. The prediction and management of neurologic complications of IE are not easily approached algorithmically, and the impact they have on timing and ability to surgically repair or replace the affected valve often requires a painstaking evaluation and joint effort across multiple medical disciplines in order to achieve the best possible outcome. Although specific recommendations are always tailored to the individual patient, there are some guiding principles that can be used to help direct the decision-making process. Herein, we review the pathophysiology, epidemiology, manifestations, and diagnosis of neurological complications of IE and further consider the impact they have on clinical decision making.

Keywords: bacterial endocarditis; brain abscess; infectious disease; intracerebral hemorrhage; meningitis; mycotic aneurysm; stroke.

Figure 1.

Stroke complicating endocarditis. Axial diffusion-weighted imaging (left) and T2 fluid-attenuated inversion recovery (FLAIR) imaging (right) of a 64-year-old female with a history of severe mitral regurgitation who presented with confusion 2 weeks after a dental procedure. Imaging shows a large right middle cerebral artery territory embolic infarct. The patient was found to have Streptococcus mitis bacteremia and mitral valve endocarditis. Vessel imaging was patent, and she underwent successful valve repair 2 weeks after antibiotics were started.

Figure 2.

Infectious intracranial aneurysm and multifocal stroke in endocarditis. Coronal computed tomography angiography (CTA) of intracranial circulation (A), axial diffusion-weighted (DWI) magnetic resonance imaging (B), and axial T2 fluid-attenuated inversion recovery (FLAIR) imaging (C) from a 54-year-old right-handed female who was found down by her family. CTA shows infective intracranial aneurysm (arrow) in the right middle cerebral artery territory, and DWI and FLAIR demonstrate innumerable bilateral embolic infarcts. The patient was found to have methicillin-sensitive Staphylococcus aureus bacteremia and endocarditis of the mitral valve, septic shock, and multiorgan failure. Despite antibiotics, the patient remained too unstable for surgical intervention and died 20 days after presentation.

Figure 3.

Multiple abscesses and ventriculitis complicating endocarditis. Axial susceptibility-weighted imaging (SWI, A), diffusion-weighted imaging (DWI, B), T1-weighted imaging after administration of gadolinium (C), and T2 fluid-attenuated inversion recovery (FLAIR) imaging (D) of a 36-year-old, right-handed man with a history of intravenous drug use who presented with malaise and multiple sites of pus-expression on the skin and in the left orbit, subsequently found to have methicillin-resistant Staphylococcus aureus bacteremia and aortic valve endocarditis. Magnetic resonance imaging shows 2 space-occupying lesions (arrow and arrow head) with internal restricted diffusion (B) and rim enhancement (C), and 1 with areas of susceptibility artifact, consistent with blood (A). Additionally, the lining of the frontal horn of the lateral ventricle demonstrates enhancement postcontrast (curved arrow, C), some diffusion restriction (B), and T2 hyperintensity (D) on FLAIR, consistent with ventriculitis. The patient underwent intensive antibiotic treatment, parapharyngeal abscess debridement, and left parietal craniectomy and lesionectomy with right frontal extraventricular drain placement with subsequent removal, and at follow up 6 months later had only residual right homonymous hemianopia and a seizure disorder. Native valve intervention was not required.