A rare case report of spontaneous thrombosis in unruptured giant intracranial aneurysm.

Unruptured giant intracranial aneurysms (GIAs) are characterized by their size, which exceeds 25 mm, and these conditions account for approximately 5% of all aneurysm cases. Furthermore, it typically develops in women during the fifth to seventh decade of life. Compared to small aneurysms, which cause subarachnoid hemorrhage, GIAs can manifest as masses or ischemic effects caused by thromboembolism. An elderly female patient, aged 67, was admitted to the hospital with a primary complaint of sudden facial sensory loss on the left side and vomiting. There was also a history of double vision accompanied by left ocular movement disturbance and gradually developed localized headache on the left side. Furthermore, a contrast head magnetic resonance angiography (MRA) revealed the presence of a high-flow giant aneurysm, measuring 30.7 × 31.8 × 27.2 mm in the cavernous segment of the left internal carotid artery (ICA). Cerebral angiography showed the absence of flow on the left ICA due to total occlusion. After cerebral angiography, the patient remained conscious but exhibited some neurological deficits, which were identical to the initial symptoms observed during hospitalization. Cases of spontaneous thrombosis in GIA are extremely rare. However, radiological examination, particularly angiography, can be used to diagnose spontaneous thrombosis in unruptured GIAs to ensure that the patient receives the right treatment.