FIGURE 122.1 Axial CT of the brain shows hyperdensity consistent with aneurysm associated with acute hemorrhage in the basal cisterns The prominence of the temporal horns of the lateral ventricles is also indicative of acute hydrocephalus Management Spontaneous cerebral aneurysms presenting with bleeding are uncommon but should be treated because of a poor natural history Imaging should be first acquired, and only if mass effect is not detected and a high suspicion of aneurysmal rupture still exists should a lumbar puncture be attempted Aggressive surgical management with clipping, resection, or trapping of intracranial dissecting aneurysms by surgical or endovascular methods seems the most appropriate treatment Cavernous Malformation