Abstract
A 65-year-old female was referred to our hospital when she experienced sudden-onset headache and vomiting. She was somnolent without any neurological deficits (WFNS Grade II, H&K G3). A head computed tomography (CT) scan showed diffuse subarachnoid hemorrhages from the basal cistern to ambient cistern with ventricular perforation into the third and fourth ventricle (Fisher group 3). Emergency four-vessel cerebral angiography showed no apparent vascular anomaly. After cerebral vasospasm was overcome, a second cerebral angiography scan was performed, and a 2-mm saccular aneurysm was detected at the top of basilar artery. Neck clipping of the cerebral aneurysm was performed. A postoperative CT revealed a small bilateral thalamic infarction due to a perforating artery injury during clipping. The patient completely regained consciousness 2 weeks later, then was discharged at mRS1 status. It is reported that 7 to 10% of initial cerebral angiography scans cannot detect the origin of bleeding of spontaneous non-traumatic subarachnoid hemorrhages. A second angiography scan can detect the source of bleeding between 2 and 22% of the time. Thrombosis of the aneurysm, hematoma compression, cryptic aneurysm, or arterial vasospasm affect the detection of ruptured intracerebral aneurysms. Even though highly resolute three-dimensional CT angiography or magnetic resonance angiography can take over the role of conventional digital subtraction angiography, and using these three methods in conjunction may increase the detection rate of cerebral aneurysm, at present, digital subtraction angiography is still the gold standard for detecting the source of bleeding of diffuse subarachnoid hemorrhages that do not show any source of bleeding in the first cerebral angiography scan.
