Clinical course of infectious intracranial aneurysm undergoing antibiotic treatment


      • Antibiotic treatment only of mycotic aneurysms had regression or resolution of aneurysm in 28%.
      • Longer antibiotic treatment before aneurysm discovery was associated with regression or resolution of mycotic aneurysm.
      • Saccular morphology of mycotic aneurysm was associated with persistence or growth of aneurysm.
      • Rupture rate of aneurysm during valve repair may be lower than previously thought.



      Infectious intracranial aneurysm (IIA, or mycotic aneurysm) is a cerebrovascular complication of infective endocarditis. We aimed to describe the clinical course of IIAs during antibiotic treatment.


      We reviewed medical records of persons with infective endocarditis who underwent cerebral angiography at a single tertiary referral center from 2011 to 2016. Aneurysms were followed with subsequent angiography for unfavorable outcome (growth, rupture, no change, or new IIA formation) or favorable outcome (regression or resolution) until endovascular therapy, aneurysm resolution, or end of observation.


      Of 618 patients included, 40 (6.5%) had 43 IIAs. Eighteen (42%) aneurysms underwent initial endovascular treatment. Twenty-five unruptured aneurysms were followed for a median 18 antibiotic days after IIA discovery (interquartile range [IQR] 4–32). Eleven (44%) aneurysms had unfavorable outcome (1 rupture, 2 new IIA formation, 6 enlargement, and 2 no change) at median 21 days (IQR 5–32). Favorable angiographic outcome was seen in 7 (28%) patients (6 resolution, 1 regression) at median 36 days (IQR 24–41). Seven aneurysms had no angiographic reevaluations but showed no evidence of rupture during clinical follow-up for median 4 days (IQR 3–12) until hospital discharge. Saccular morphology was associated with unfavorable aneurysmal outcome (p = 0.013). Longer duration of antibiotic exposure prior to IIA discovery was associated with favorable aneurysmal outcome (p = 0.046).


      IIAs represent a dynamic disease. Only a quarter of IIAs resolve with antibiotics alone. Saccular aneurysmal morphology might predict unfavorable aneurysmal outcome. IIA found after longer antibiotic therapy has higher likelihood of resolution or regression on antibiotic treatment.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Journal of the Neurological Sciences
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Ducruet A.F.
        • Hickman Z.L.
        • Zacharia B.E.
        • et al.
        Intracranial infectious aneurysms: a comprehensive review.
        Neurosurg. Rev. 2010; 33: 37-46
        • Hodges K.E.
        • Hussain S.T.
        • Stewart W.J.
        • et al.
        Surgical management of infective endocarditis complicated by ischemic stroke.
        J. Card. Surg. 2017; 32: 9-13
        • Kannoth S.
        • Thomas S.V.
        Intracranial microbial aneurysm (infectious aneurysm): current options for diagnosis and management.
        Neurocrit. Care. 2009; 11: 120-129
        • von Elm E.
        • Altman D.G.
        • Egger M.
        • et al.
        STROBE initiative.The strengthening the reporting of observational studies in epidemiology (STROBE)statement: guidelines for reporting observational studies.
        J. Clin. Epidemiol. 2008; 61: 344-349
        • Durack D.T.
        • Lukes A.S.
        • Bright D.K.
        New criteria for diagnosis of infective endocarditis: utilization of specific echocardiographic findings. Duke endocarditis service.
        Am. J. Med. 1994; 96: 200-209
        • Greenberg S.M.
        • Eng J.A.
        • Ning M.
        • et al.
        Hemorrhage burden predicts recurrent intracerebral hemorrhage after lobar hemorrhage.
        Stroke. 2004; 35: 1415-1420
        • Kannoth S.
        • Iyer R.
        • Thomas S.V.
        • et al.
        Intracranial infectious aneurysm: presentation, management and outcome.
        J. Neurol. Sci. 2007 May; 256: 3-9
        • Chun J.Y.
        • Smith W.
        • Halbach V.V.
        • et al.
        Current multimodality management of infectious intracranial aneurysms.
        Neurosurgery. 2001 Jun; 48: 1203-1204
        • Corr P.
        • Wright M.
        • Handler L.C.
        Endocarditis-related cerebral aneurysms: radiologic changes with treatment.
        AJNR Am. J. Neuroradiol. 1995 Apr; 16: 745-748
        • Chalouhi N.
        • Hoh B.L.
        • Hasan D.
        Review of cerebral aneurysm formation, growth, and rupture.
        Stroke. 2013 Dec; 44: 3613-3622
        • Okazaki S.
        • Sakaguchi M.
        • Hyun B.
        • et al.
        Cerebral microbleeds predict impending intracranial hemorrhage in infective endocarditis.
        Cerebrovasc. Dis. 2011; 32: 483-488
        • Cho S.-M.
        • Rice C.
        • Marquardt R.J.
        • et al.
        Magnetic resonance imaging susceptibility-weighted imaging lesion and contrast enhancement may represent infectious intracranial aneurysm in infective endocarditis.
        Cerebrovasc. Dis. 2017; 44: 210-216
        • Cho S.-M.
        • Marquardt R.J.
        • Rice C.J.
        • et al.
        Cerebral microbleeds predict infectious intracranial aneurysm in infective endocarditis.
        Eur. J. Neurol. 2018; 25: 970-975
        • John S.
        • Walsh K.M.
        • Hui F.K.
        • et al.
        Dynamic angiographic nature of cerebral mycotic aneurysms in patients with infective endocarditis.
        Stroke. 2016; 47: e8-e10
        • Peters P.J.
        • Harrison T.
        • Lennox J.L.
        A dangerous dilemma: management of infectious intracranial aneurysms complicating endocarditis.
        Lancet Infect. Dis. 2006 Nov; 6: 742-748
        • Gillinov A.M.
        • Shah R.V.
        • Curtis W.E.
        • et al.
        Valve replacement in patients with endocarditis and acute neurologic deficit.
        Ann. Thorac. Surg. 1996; 61: 1125-1129