Two Cases of Subarachnoid Hemorrhage with Microaneurysmal Changes and Spontaneous Disappearance in the Basilar Artery

Abstract

A 79-year-old woman presented at our hospital with sudden headache and vomiting. Computed tomography revealed diffuse subarachnoid hemorrhage. Although digital subtraction angiography (DSA) performed on admission and on the following day revealed no vascular abnormalities, DSA on Day 22 revealed microaneurysmal changes in the dorsal basilar artery. However, the aneurysmal changes gradually became smaller during follow-up, and DSA on Day 73 revealed complete disappearance. A 53-year-old man also presented to our hospital with sudden headache and vomiting. Computed tomography revealed perimesencephalic subarachnoid hemorrhage. DSA on Days 9 and 16 revealed microaneurysmal changes in the dorsal basilar artery. Conservative treatment was continued, and DSA on Day 42 revealed spontaneous disappearance of the lesion. It has been reported that basilar artery perforating aneurysms cause angiogram-negative subarachnoid hemorrhage, which disappears spontaneously. The fact that lesions previously reported as basilar artery perforating aneurysms may include cases of acute dissection of the main trunk or perforating branches of the basilar artery implies that surgical or endovascular treatment may worsen the condition. Therefore, conservative treatment may be an important option.

Keywords: basilar artery; basilar artery perforating aneurysm; subarachnoid hemorrhage of unknown etiology.

Fig. 1

Initial computed tomography image showing diffuse subarachnoid hemorrhage in the bilateral Sylvian fissure and basal cistern (a). On admission, three-dimensional rotation angiography (3D-RA) of the right vertebral artery revealed no vascular anomalies (b). Right vertebral angiography (c) and 3D-RA (d) on Day 22 revealed a microaneurysmal change (arrow) of approximately 2 mm in the dorsal basilar artery. Computed tomography angiography on Day 35 detected a microaneurysmal change (arrow) (e). However, 3D-RA on Day 73 revealed complete disappearance of the lesion (f).

Fig. 2

Initial computed tomography showing subarachnoid hemorrhage localized in the interpeduncular cistern (a). Although three-dimensional rotation angiography (3D-RA) revealed no vascular anomaly on admission (b), 3D-RA on Day 9 revealed a small aneurysmal change (arrow) of approximately 1 mm in the dorsal basilar artery (c). 3D-RA on Day 42 revealed complete disappearance of the lesion (d).