Angiogram-Negative Subarachnoid Hemorrhage: Relationship Between Bleeding Pattern and Clinical Outcome

Abstract

The overall incidence of true aneurysms in patients with angiogram-negative SAH is low (2.9%). Initial bleeding pattern strongly correlates with diagnostic yield and clinical outcome. Diffuse bleeding pattern is associated with significantly higher diagnostic yield, more in-hospital complications, and worse clinical outcome. Patients with initial imaging characteristics other than diffuse pattern SAH developed few disease related complications, with the majority of in-hospital adverse events treatment related.

Pattern Not Volume of Bleeding Predicts Angiographic Vasospasm in Nonaneurysmal Subarachnoid Hemorrhage

“…7 Most prior studies have assumed that the higher risk of vasospasm in those with diffuse bleeding was mediated by differences in blood burden. 4 We are the first to measure Hijdra scores in a large cohort with diffuse versus PM-SAH, confirming that although diffuse bleeding is associated with more intracranial blood, this disparity does not seem to explain the vasospasm risk. In fact, we did not find an association between blood burden and vasospasm (whether quantified or categorized) in contradistinction to studies in aneurysmal SAH which correlate Hijdra score with risk of vasospasm/DCI.…”

“…1,2 Of these nonaneurysmal (idiopathic) patients, those with a perimesencephalic pattern of bleeding (PM-SAH) have a favorable prognosis, 3 whereas those with diffuse bleeding may have worse outcomes. [4][5][6] Although predictors of vascular lesions on subsequent evaluation have been studied, less is known about which patients are at risk for vasospasm and delayed cerebral ischemia (DCI) and may benefit from closer neurological monitoring.…”

Factors Associated with Acute and Chronic Hydrocephalus in Nonaneurysmal Subarachnoid Hemorrhage

“…It is unclear whether the incidence of hydrocephalus is truly lower in NA-SAH compared to SAH with aneurysmal etiologies, especially NA-SAH in the context of diffuse (aneurysmal-like) bleeding pattern. Furthermore, it unclear whether there is something intrinsic to the pathophysiology of diffuse bleeding that confers a greater risk of hydrocephalus in comparison to PM-SAH [9,16,17]. However, it is not clear whether such a relationship is mediated through the increased burden of cisternal and intraventricular blood that may be associated with diffuse bleeding.…”

Intracranial vessel wall MRI: a review of current indications and future applications

“…This represents an important future research direction for IVWM studies of patients with non-traumatic subarachnoid hemorrhage who have a negative initial catheter angiogram, which is 10-20 % of patients [66,67]. The yield of repeat catheter angiography is low in this population and IVWM may allow the identification of the causative pathology and lead to management strategies that reduce future morbidity [68].…”