Spontaneous Intracranial Artery Dissection causing Subarachnoid Hemorrhage: Importance of Short-Term Surveillance

Abstract

Hemorrhagic intracranial artery dissections are unstable lesions, with a high propensity for rebleeding (up to 40%) in the acute period. Imaging plays an important role in the diagnosis and management of intracranial artery dissections. In this paper, we describe 2 cases in which the dissected intracranial artery underwent rapid morphological change within 3 days or less, highlighting the importance of short-term follow-up imaging in patients with these hemorrhagic lesions.

Keywords: Intracranial vertebral artery dissection; hemorrhagic intracranial dissection; intracranial dissection; subarachnoid hemorrhage.

Figure 1.

Figure 1A is an axial non-contrast head CT, showing subarachnoid hemorrhage filling the basal cisterns (arrow). There is also dilatation of the temporal horns, reflecting hydrocephalus (arrowheads). Figure 1B is an axial CTA of the head, showing decreased opacification and occlusion (on a more cephalad slice) of the right vertebral artery (arrow). The left vertebral artery is normal (arrowhead). Figure 1C is a digital subtract angiogram of the right vertebral artery injection in the frontal projection, showing the distal V2, V3, and V4 segments of the right vertebral artery. There is abrupt occlusion of the intradural/V4 segment of the right vertebral artery (arrow). Figure 1D is a frontal projection repeat cerebral angiogram performed 3 days after presentation, showing recanalization of the previously occluded right vertebral artery, with a new pseudoaneurysm at the site of dissection (arrow). Figure 1E is a frontal projection, right vertebral artery injection digital subtraction angiogram (DSA) immediately following coiling of the pseudoaneurysm, with exclusion of the pseudoaneurysm from circulation (arrow). Figure 1F is a frontal projection left vertebral injection DSA showing no retrograde filling of the coiled pseudoaneurysm.

Figure 2.

Figure 2A is an axial noncontrast CT of the head, showing diffuse subarachnoid hemorrhage (arrows), with intraventricular extension (arrowhead). Figure 2B is a maximum intensity projection of a coronal CTA, showing mild fusiform dilatation of the right A1-A2 junction (arrowhead), suspicious for a dissecting pseudoaneurysm. Figure 2C is a diagnostic cerebral angiogram in the frontal projection during a right internal carotid artery injection, showing interval increase in the dissecting right A1-A2 junction pseudoaneurysm (arrowhead). Figure 2D is a follow-up axial CTA head performed a week later showing 2 overlapping stents spanning the dissected right A1-A2 junction pseudoaneurysm (arrowhead), with no further filling of the pseudoaneurysm.