A case of ruptured lateral spinal artery aneurysm diagnosed as SAH of unverified etiology at initial examinations

Abstract

We report a case of a ruptured lateral spinal artery tiny aneurysm of the hypoplastic left VA originating from the aortic arch diagnosed as SAH of unverified etiology at initial examinations. This was the case of a 59-year-old man with a headache, vomiting, and consciousness disturbance. Initial head CT revealed typical SAH, but neither initial head CT angiography (CTA) nor DSA showed an aneurysm or vascular anomaly. Follow-up head CTA on days 6 and 13 showed left VA running an anomalous course that entered the spinal canal at the level between the C1 and C2 vertebral bodies and had a tiny aneurysm at the C1 vertebral body level. We also focused on the possibility that rupture of this aneurysm could cause left dominant abducens nerve palsy. Subsequently, coil embolization for this aneurysm was performed. This case was specific to the point of the lateral spinal artery with multiple normal variations of VA, non-predilection site, and tiny aneurysm. In SAH of unverified etiology, it is important to seek causes without preconception.