Ruptured intracranial mycotic aneurysm in infective endocarditis: a natural history

Abstract

Mycotic aneurysms are a rare cause of intracranial aneurysms that develop in the presence of infections such as infective endocarditis. They account for a small percentage of all intracranial aneurysms and carry a high-mortality rate when ruptured. The authors report a case of a 54-year-old man who presented with infective endocarditis of the mitral valve and acute stroke. He subsequently developed subarachnoid hemorrhage during antibiotic treatment, and a large intracranial aneurysm was discovered on CT Angiography. His lesion quickly progressed into an intraparenchymal hemorrhage, requiring emergent craniotomy and aneurysm clipping. Current recommendations on the management of intracranial Mycotic Aneurysms are based on few retrospective case studies. The natural history of the patient's ruptured aneurysm is presented, as well as a literature review on the management and available treatment modalities.

Figure 1

MRI of brain on presentation: (a) sagital view showing acute right side frontal lobe infarct marked by arrow. (b) Axial view with same right side frontal lobe infarct marked by arrow. (c) Diffusion-Weighted Image of ischemic stroke in the right centrum semiovale.

Figure 2

Four chamber view echocardiogram showing large vegetation on the MVL marked by arrow. LV-left ventricle, LA-left atrium, RV-right ventricle, RA-right atrium, TV-tricuspid valve, MVL-mitral valve leaflet.

Figure 3

Progression of the ruptured Mycotic Aneurysm: (a) initial subarachnoid hemorrhage after 6 days IV antibiotics. Note interhemispheric hemorrhage. (b) Repeat noncontrast CT Brain 12 hours later, intraparenchymal hemorrhage is marked by arrow. Note prominent basal ganglia calcifications.

Figure 4

CT Cerebral angiogram showing a large fusiform aneurysm at the distal anterior cerebral artery (ACA). (a) Shaded Surface Display CT coronal view showing a large fusiform aneurysm at the distal segment of the ACA marked by the large arrow. Proximal ACA segments are marked by the smaller arrows. RIC: right internal carotid artery, LIC: left internal carotid artery, RMCA: right middle cerebral artery, LMCA-left middle cerebral artery, RACA and LACA are right and left anterior cerebral arteries, respectively. (b) Close-up coronal view of ACA mycotic aneurysm. (c) Additional sagital view of mycotic aneurysm. (d) CT Angiogram axial view, an arrow marks the location of the ruptured aneurysm adjacent to a large hemorrhagic lesion. (e) CT Angiogram sagital view demonstrating areas of intracerebral hemorrhage.

Figure 5

One week postoperative CT imaging demonstrating a metallic clip in the ACA, and a ventriculostomy in the lateral ventricle.