Completely Thrombosed Giant Intracranial Aneurysm with Spontaneous Thrombosis of the Parent Artery: Is It Nature's Divine Intervention and a Self-Cure?

BACKGROUND

Although partial thrombosis is common with intracranial aneurysms, complete aneurysmal thrombosis is extremely rare. An even rarer and seldom reported phenomenon is the spontaneous complete occlusion of the parent artery in the presence of a thrombosed aneurysm. Given the unclear natural history of this phenomenon, therapeutic decision making may be rather difficult. Here we report a case of right cavernous carotid artery aneurysm with spontaneous right internal carotid artery (ICA) thrombosis in a 45-year-old man.

CASE DESCRIPTION: Our patient presented almost 1 month after an episode of sudden-onset severe holocranial headache associated with vomiting that had resolved completely within 2 days. He was neurologically intact at the time of presentation. A computed tomography (CT) scan done at the time of ictus showed a rounded hyperdensity with the epicenter at the right parasellar region along with nonvisualization of the ipsilateral ICA on CT angiography. Magnetic resonance imaging (MRI) suggested a diagnosis of a completely thrombosed right cavernous segment ICA aneurysm. Intra-arterial angiography confirmed a complete ipsilateral ICA thrombosis and a good arterial cross-flow from the left side to the bilateral anterior and middle cerebral artery territories. We started the patient on oral aspirin and a close clinicoradiologic follow-up after having decided against any active intervention.

CONCLUSIONS

Spontaneous thrombosis of an intracranial aneurysm and the parent artery is rare, with only a few cases reported in the literature. In the absence of symptoms and adequate collateral circulation, these patients are perhaps best managed conservatively.