title: Ruptured mycotic cerebral aneurysm development from pseudoocclusion due to septic embolism.
abstract: BACKGROUND
  Cerebral mycotic aneurysms are rare sequelae of systemic infections that can cause profound morbidity and mortality with rupture. Direct bacterial extension and vessel integrity compromise from septic emboli have been implicated as mechanisms for formation of these lesions. We report the 5-day development of a ruptured mycotic aneurysm arising from a septic embolism that caused a focal M1 pseudoocclusion.
  
  
  METHODS
  A 14-year-old girl developed acute left-sided hemiparesis while hospitalized for subacute bacterial endocarditis that was found after she presented with a 2-week history of fever, myalgia, shortness of breath, and lethargy. Mitral valve vegetations were confirmed in the setting of hemophilus bacteremia. Brain magnetic resonance (MR) imaging and angiography confirmed middle cerebral artery infarct with focal pseudoocclusion of the distal M1 segment. Given that further middle cerebral artery territory was at risk, a trial of heparin was attempted for revascularization but required discontinuation owing to hemorrhagic conversion. Decline of the patient's mental status necessitated craniectomy for decompression. Postoperatively, her mental status improved with residual left hemiparesis. On the third postoperative day (5 days after MR angiography), the patient's neurologic condition acutely declined, with development of right-sided mydriasis. Computed tomography (CT) angiography revealed a ruptured 19 × 16 mm pseudoaneurysm arising from the M1 site of the previous occlusion. Emergent coiling of aneurysm and parent vessel followed by hematoma evacuation ensued. At discharge, the patient had residual left hemiparesis but intact speech and cognition.
  
  
  CONCLUSIONS
  Focal occlusions due to septic emboli should be considered high-risk for mycotic aneurysm formation, prompting aggressive monitoring with neuroimaging and treatment when indicated.
authors: Department of Neurosurgery, School of Medicine and Biomedical Sciences, Buffalo, New York, USA ; Department of Neurosurgery, Gates Vascular Institute, Kaleida Health, Buffalo, New York, USA.
authors: Grant C
authors: GC
authors: Sorkin
authors: Naser
authors: N
authors: Jaleel
authors: Maxim
authors: M
authors: Mokin
authors: Travis M
authors: TM
authors: Dumont
authors: Jorge L
authors: JL
authors: Eller
authors: Adnan H
authors: AH
authors: Siddiqui
keywords: Cerebral aneurysm; infective endocarditis; mycotic aneurysm; septic emboli