Adult subarachnoid hemorrhage from vein of Galen aneurysmal malformation due to ruptured feeder aneurysm: A case report with long-term MRI review.

Adult hemorrhage from a previously treated vein of Galen aneurysmal malformation (VGAM) is exceedingly rare, and rupture of a flow-related feeder aneurysm has only been documented once in the adult case. We report a 20-year-old man with subarachnoid hemorrhage who presented with sudden headache. He had undergone palliative transarterial embolization (TAE) for choroidal-type VGAM during infancy for several times and had been followed annually with MRI at another institution. Digital subtraction angiography demonstrated two small feeder aneurysms, one presumed to have ruptured; additional embolization achieved complete occlusion of both aneurysms and a marked reduction in shunt flow. Retrospective review of serial MRIs showed progressive stenosis and eventual occlusion of the left transverse sinus, with first visualization of a feeder aneurysm one year prior to the rupture. This case represents only the second adult VGAM hemorrhage clearly attributed to a feeder artery aneurysm. Progressive venous sinus changes on follow-up MRI should prompt early angiographic re-evaluation and consideration of prophylactic treatment based on individual hemodynamic risk.