A case of multiple cerebral aneurysms with false localization of subarachnoid hemorrhage and misdiagnosis of the ruptured aneurysm

Abstract

It is important to determine the site of rupture in subarachnoid hemorrhage (SAH) patients associated with multiple cerebral aneurysms. However, an unusual radiological presentation of subarachnoid hemorrhage can result in the misdiagnosis of the rupture site. A 32-old-woman had sudden onset of severe headache and was visited our hospital. CT scan showed thin SAH in the right sylvian fissure and a small blood clot located in front of the brainstem. CT angiography (CTA) showed a right internal carotid-posterior communicating (IC-PC) artery aneurysm and an aneurysm of a fenestrated basilar (FBA) artery. It was difficult to determine the precise bleeding site preoperatively Because of the predominant SAH in the right sylvian fissure on CT scans, the origin of the hemorrhage was suspected to be a right IC-PC artery aneurysm, and clipping was performed. However, hemorrhage recurred four days after clipping. Cerebral angiography suggested a diagnosis of hemorrhage from an FBA artery aneurysm. Endovascular embolization was performed, and both episode of SAH were considered to be attributed to this aneurysm. Postoperative course of the patient was uneventful. Misjudgment may result in disastrous postoperative rebleeding from the untreated but true ruptured lesion. Correct diagnosis of ruptured aneurysm with confirmation of aneurysm location and proper therapeutic treatment are directly connected to prognosis. It is therefore necessary to perform detailed evaluation of a suspected rupture site and to select the appropriate treatment.