Visualization of a Traumatic Pseudoaneurysm at Internal Carotid Artery Bifurcation due to Blunt Head Injury: A Case Report

Traumatic intracranial pseudoaneurysms occurring after blunt head injuries are rare. We report an unusual case of subarachnoid hemorrhage (SAH) caused by rupturing of the traumatic pseudoaneurysm of the internal carotid artery (ICA) bifurcation that resulted from a non-penetrating injury. In a patient with severe headache and SAH in the right sylvian cistern, which developed within 7 days after a blunt-force head injury, a trans-femoral cerebral angiogram (TFCA) showed aneurysmal sac which was insufficient to confirm the pseudoaneurysm. We obtained a multi-slab image of three dimensional time of flight (TOF) of magnetic resonance angiography (MRA). The source image of the gadolinium-enhanced MRA revealed an intimal flap within the intracranial ICA bifurcation, providing a clue for the diagnosis of a dissecting pseudoaneurysm at the ICA bifurcation due to blunt head trauma. We performed direct aneurysmal neck clipping, without neurological deficit. A follow-up TFCA did not show either aneurysm sac or luminal narrowing. We suggest that in the patient with a history of blunt head injury with SAH following shortly, multi-slab image of 3D TOF MRA can give visualization of the presence of a pseudoaneurysm.