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Updated: Oct 11, 2025
Pre-Chiasmatic, Single Injection of Autologous Blood to Induce Experimental Subarachnoid Hemorrhage in a Rat Model
Published on: June 18, 2021
Spontaneous angiogram-negative subarachnoid hemorrhage: a retrospective single center cohort study
Alexander Achrén1, Rahul Raj2, Jari Siironen2
1Department of Neurosurgery, University of Helsinki and Helsinki University Hospital, Töölö Hospital, HUS, Topeliuksenkatu 5, PO. Box. 266, 00029, Helsinki, Finland. alexander.achren@helsinki.fi.
Background:
Spontaneous angiogram-negative subarachnoid hemorrhage (SAH) is considered a benign illness with little of the aneurysmal SAH-related complications. We describe the clinical course, SAH-related complications, and outcome of patients with angiogram-negative SAH.
Methods:
We retrospectively reviewed all adult patients admitted to a neurosurgical intensive care unit during 2004-2018 due to spontaneous angiogram-negative SAH. Our primary outcome was a dichotomized Glasgow Outcome Scale (GOS) at 3 months. We assessed factors that associated with outcome using multivariable logistic regression analysis.
Results:
Of the 108 patients included, 84% had a favorable outcome (GOS 4-5), and mortality was 5% within 1 year. The median age was 58 years, 51% were female, and 93% had a low-grade SAH (World Federation of Neurosurgical Societies grading I-III). The median number of angiograms performed per patient was two. Thirty percent of patients showed radiological signs of acute hydrocephalus, 28% were acutely treated with an external ventricular drain, 13% received active vasospasm treatment and 17% received a permanent shunt. In the multivariable logistic regression model, only acute hydrocephalus associated with unfavorable outcome (odds ratio = 4.05, 95% confidence interval = 1.05-15.73). Two patients had a new bleeding episode.
Conclusion:
SAH-related complications such as hydrocephalus and vasospasm are common after angiogram-negative SAH. Still, most patients had a favorable outcome. Only acute hydrocephalus was associated with unfavorable outcome. The high rate of SAH-related complications highlights the need for neurosurgical care in these patients.
