Non-aneurysmal subarachnoid hemorrhage: When is a second angiography indicated?

Abstract

Purpose Repeat imaging in patients with non-aneurysmal subarachnoid hemorrhage (NASAH) remains controversial. We aim to report our experience with NASAH with different hemorrhage patterns, and to investigate the need for further diagnostic workup to determine the underlying cause of hemorrhage. Method We conducted a retrospective analysis of all spontaneous SAH with an initial negative computed tomography (CT) with angiography (CTA) and/or digital subtraction angiography (DSA) from October 2011 through May 2017. According to the bleeding pattern on the admission CT scan, NASAH was divided into two subgroups: (1) perimesencephalic SAH (PMSAH) and (2) non-perimesencephalic SAH (nPMSAH). Radiological data included the admission CT, CTA, DSA, and magnetic resonance imaging (MRI) with angiography (MRA). Results Seventy-four patients met the inclusion criteria. Thirty-nine (52.7%) patients had PMSAH on the initial CT scan, and 35 (47.3%) had nPMSAH. All underwent CTA and/or DSA revealing no vascular abnormalities. Forty-seven (63.5%) patients underwent subsequent diagnostic workup. DSA was performed in all patients at least once. No abnormalities were found on the repeat DSA or other radiological follow-up studies except in one (1.4%) patient with nPMSAH, in whom a follow-up DSA revealed a small saccular anterior choroidal artery aneurysm, considered to be the source of hemorrhage. Conclusion A repeat DSA may not be needed in case of PMSAH, if the initial negative DSA is technically adequate with absence of hematoma and vasospasm. In contrast, a follow-up DSA should be mandatory for confirming or excluding vascular pathology in case of nPMSAH in order to prevent rebleeding.

Keywords: Non-aneurysmal subarachnoid hemorrhage; cerebral angiography; digital subtraction angiography; perimesencephalic subarachnoid hemorrhage.

Figure 1.

Initial computed tomography scan. Images 1(a)–(c) show a non-contrast computed tomography scan with a moderate to severe subarachnoid hemorrhage in the basal cisterns and Sylvian fissures bilaterally and a small amount of intraventricular blood in the posterior part of the lateral horns.

Figure 2.

Initial computed tomography angiography and digital subtraction angiography. Images 2(a) and (b) show computed tomography angiography with normally calibrated vessels with no vascular pathology, which was verified by digital subtraction angiography (Images 2(c)–(f)).

Figure 3.

Computed tomography scan at second admission. Images 3(a)–(c) show a non-contrast computed tomography scan that demonstrated a severe rebleeding located occipitally and along the tentorium cerebelli and right posterior communicating artery. Increasing hydrocephalus.

Figure 4.

Computed tomography angiography and digital subtraction angiography at second admission. Images 4(a) and (b) show computed tomography angiography with normally calibrated vessels with no sign of aneurysms or arteriovenous malformation. Images 4(c)–(f) reveal a small right-sided saccular anterior choroidal aneurysm measuring 2 × 3.6 mm.