Pseudoaneurysm of the anterior spinal artery in a patient with Moyamoya: an unusual cause of subarachnoid hemorrhage

Abstract

Subarachnoid hemorrhage (SAH) is a recognized presentation of Moyamoya disease in adults. Because there are extensive collateral networks and potential complications that develop, a thorough investigation of the intracranial and extracranial circulation is necessary to exclude a treatable cause when these patients present with SAH. We present a case of SAH due to a ruptured pseudoaneurysm of the anterior spinal artery arising from the supreme intercostal artery, which was the sole source of blood supply to the intracranial circulation.

Fig 1.

Lateral views from digital subtraction angiography with selective injection of the left (A) and right (B) internal carotid arteries reveals bilateral supraclinoid occlusion of the internal carotid arteries with prominent collaterals via the ophthalmic artery, the meningohypophyseal trunk, and hypertrophied lenticulostriates.

Fig 2.

MRA 3D time-of-flight technique (A) demonstrates hypertrophied posterior communicating arteries (white arrows) feeding the anterior circulation. Lateral oblique views (B and C) by use of a Vitrea workstation once again demonstrate prominence of the posterior communicating arteries (white arrows) as well as evidence of occlusive disease involving the internal carotid arteries bilaterally (white arrowheads).

Fig 3.

Sagittal and axial (A and B) T1-weighted images of the cervical spine reveal a mixed signal intensity intradural mass at approximately the level of C4. This mass appears to contain blood products of varying age. Postgadolinium sagittal and axial (C and D) sequences reveal vague peripheral enhancement around the intradural mass.

Fig 4.

Axial source image from a CT angiogram reveals an attenuated homogeneously enhancing mass at the C4 level. The enhancement pattern matches that of the carotid vessels, which indicates the vascular nature of this lesion.

Fig 5.

Reconstructed 3D image by use of a Vitrea workstation demonstrates an irregularly shaped aneurysm arising from an enlarged anterior spinal artery.

Fig 6.

Digital subtraction angiography frontal (A) and lateral (B) projections with injection of the supreme intercostal artery (black arrow) reveal an enlarged anterior spinal artery (white arrow) arising from the supreme intercostal artery feeding the basilar artery (black arrowhead) and the intracranial circulation. A bilobed pseudoaneurysm is seen arising from the anterior spinal artery.

Fig 7.

Postembolization digital subtraction angiography images in the frontal (A) and lateral (B) projections reveal a coil mass and complete obliteration of the previously noted pseudoaneurysm. Continued patency of the anterior spinal artery is demonstrated.