Introduction Infectious intracranial aneurysms (IIAs) are a rare complication of infective endocarditis as well as systemic and intracranial infections. IIAs are often diagnosed upon rupture but have a similar presentation to non-infectious aneurysms (NIAs) with subarachnoid hemorrhage (SAH). Although vasospasm is a common complication of both SAH and meningitis, the incidence, timing, and management of vasospasm in IIA patients are yet to be studied which is the objective of this work.

Methods This is a retrospective study of patients presenting with SAH secondary to IIAs or NIAs between 5/2015 and 1/2023. Patients with SAH who died within 48 hours were excluded from this study. Patients’ charts were reviewed for demographics, imaging findings, management, the timing of vasospasm, severity of vasospasm, and vasospasm management. Propensity score matching was used to compare patients with IIAs versus NIAs. The patients were matched with a ratio of 1:5 based on their age, gender, race, comorbidities, and fisher score. Incidence, rate, and management of vasospasm were computed for each cohort.

Results A total of 20 patients with ruptured IIAs were included in this study of which 30% (n=6) developed post-ruptured vasospasm. Vasospasm was diagnosed using combined daily trans-cranial doppler (TCD) and surveillance CTA in all patients. Of patients with vasospasm, 1 patient had mild vasospasm, 2 had moderate and 3 had severe, as defined on CTA by an independent radiologist. Among patients with vasospasm, 83% had neurological deficits due to vasospasm. Vasospasm was managed using intrathecal nicardipine in 5 patients (83%), while 1 patient required intra-arterial milrinone and 1 patient underwent angioplasty and stenting. When comparing with the NIAs matched cohort, there was no significant difference in age, comorbidities, modified fisher score, smoking history, or time to presentation indicating balanced matching. Compared to NIAs, patients with IIAs had a comparable rate of vasospasm (30% vs 39%, p= 0.448). However, patients with IIAs developed vasospasm significantly earlier with a mean time from rupture to spasm of 3.5±1.05 days compared to 5.81±3.48 days in NIAs (p=0.002).

Conclusion Patients with ruptured IIAs are at a similar risk of vasospasm compared to NIAs with similar blood pattern and modified fisher score; however, they develop symptomatic and radiographic evidence of vasospasm earlier in the course of their disease. These findings argue for the need for routine and early screening for vasospasm in patients with ruptured IIAs.

Disclosures Y. Zohdy: None. L. Dimisko: None. J. Grossberg: None. G. Pradilla: None. T. Garzon-Muvdi: None. D. Barrow: None. C. Cawley: None. O. Sadan: None. O. Samuels: None. A. Alawieh: None. B. Howard: None.