Increasing numbers of nonaneurysmal subarachnoid hemorrhage in the last 15 years: antithrombotic medication as reason and prognostic factor?

Abstract

S ubarachnoid hemorrhage (SAH) is usually caused by intracranial aneurysm rupture. However, in up to 20% of patients with SAH, results of cerebral angiography, CT, and MRI are negative for aneurysms or other vascular malformations. 2,7,11 More recent data show an increasing number of cases of spontaneous SAH 18,24 as well as nonaneurysmal SAH (NASAH). 15,16 Long-term dipyridamole and warfarin use were associated with an increased risk for aneurysmal SAH (aSAH), whereas the data for low-dose acetylsalicylic acid (LDA) were inconsistent. 10,14,21 Therefore, we analyzed our institutional database for patients suffering from angiography-negative SAH. The aim of the study was to identify risk factors for the increase of NASAH as well as analyze outcome.abbreviatioNs aCP = systemic anticoagulation or antiplatelet agent; aSAH = aneurysmal subarachnoid hemorrhage; CVS = cerebral vasospasm; DCI = delayed cerebral infarction; DSA = digital subtraction angiography; LDA = low-dose acetylsalicylic acid; mRS = modified Rankin Scale; NASAH = nonaneurysmal SAH; NPM = nonperimesencephalic; PM = perimesencephalic; SAH = subarachnoid hemorrhage; WFNS = World Federation of Neurosurgical Societies.

Cerebral vasospasm and delayed cerebral infarctions in 225 patients with non-aneurysmal subarachnoid hemorrhage: the underestimated risk of Fisher 3 blood distribution

“…Recent data have shown increasing numbers of patients with SAH and NASAH 1 19. Nonetheless, SAH without identification of a bleeding source is assumed to have a good outcome 6 20–22.…”

“…As previously shown, non-aneurysmal subarachnoid hemorrhage (NASAH) is an increasing entity 1. Also, in about 15–25% of patients with subarachnoid hemorrhage (SAH), cerebral angiography, CT scan, and spinal MRI are negative for aneurysms or other vascular malformations 2–5.…”

MRI-detection rate and incidence of lumbar bleeding sources in 190 patients with non-aneurysmal SAH

“…Patients in whom the bleeding source was detected to be an aneurysm or vascular malformation were excluded from the study and treated by surgical or endovascular aneurysm occlusion based on an interdisciplinary consensus [2]. If absence of intracranial vascular pathology was confirmed by a neuroradiologist, patients received a 2 nd angiography regularly approximately 14 days to 60 days after the ictus.…”

“…In up to 15% of all spontaneous subarachnoid hemorrhages, there is no evidence of an intracranial vascular pathology [1]. Recently published data showed increasing numbers of patients with non-aneurysmal SAH (NASAH) [2]. The evaluation of patients with subarachnoid hemorrhage with negative digital subtraction angiography (DSA) is therefore important and furthermore sometimes a diagnostic challenge.…”

“…As possible explanations, vascular malformations, ruptured aneurysms of perforating arteries or small venous anomalies, atypical venous drainage patterns, basilar artery dissection, trauma, influence of antithrombotic medication and a case of a spinal vascular malformation, have been described [2,8,10,11,12,13,14]. …”