case_images: PMC4192925_01
case_images: Skull CT revealing SAH in basal cisterns, hydrocephalus and hemoventricle in posterior fossa; brain MR disclosing laminar hemorrhage in T1 sagittal and axial images, just ahead of cervicomedullary junction; cerebral angiogram: In A, anteroposterior view of posterior circulation with no abnormalities. In B, lateral view. In C, a small aneurysm in ASA is noted, which is better exposed in D
case_images: SNI-5-139-g001.jpg
case_images: PMC4192925_01_SNI-5-139-g001.jpg
case_images: F1
case_images: She underwent a computed tomography (CT) scan of the head, which revealed SAH, intraventricular hemorrhage, and hydrocephalus [Figure 1]. Magnetic resonance imaging (MRI) of the neck revealed a laminar bleed at the right anterior cervicomedullary junction [Figure 1]. At that time, a 2-mm saccular aneurysm was found in the ASA, presumably the cause of SAH [Figure 1].
case_images: An angiotomography of intracranial vessels, which could not identify the ASA aneurysm
case_images: SNI-5-139-g002.jpg
case_images: PMC4192925_01_SNI-5-139-g002.jpg
case_images: F2
case_images: CT angiography performed at the same time could not display the aneurysm clearly [Figure 2].
case_images: Amplified image of ASA aneurysm at diagnosis, with 2 mm of diameter. At right, control angiogram 3 months after bleeding, revealing normal posterior circulation
case_images: SNI-5-139-g003.jpg
case_images: PMC4192925_01_SNI-5-139-g003.jpg
case_images: F3
case_images: Monthly routine angiograms revealed resolution of the aneurysm 90 days after bleeding (angiograms at 1- and 2-month follow-up were quite similar), which was highly suggestive of vascular dissection [Figure 3].