Subarachnoid hemorrhage (SAH) with spinal etiology is present in less than 1% of all cases with SAH. 1 The most frequent cause of spinal SAH is rupture of spinal cord pial arterio-venous malformations (ScAVMs) followed by hemorrhage from highly vascular spinal tumors such as ependymoma or hemangioblastoma. Aneurysms arising from spinal arteries are extremely rare with an incidence of about one in more than 3,000 spinal angiograms. 2 Spinal aneurysms are usually flow related aneurysms associated with ScAVM 3 and less commonly in dural arterio-venous fistulas (DAVF) 4 and in patients with coarctation of the aorta, bilateral vertebral occlusion or Moya-moya disease in whom the anterior spinal artery (ASA) serves as collateral supply. Isolated aneurysms not associated with these conditions are very rare. 5 We report a case of isolated ruptured radiculopial artery aneurysm presenting with spinal SAH.
CASE REPORTA 72-years-old female presented with sudden onset of the worst back pain of her life while sitting on a chair. The pain was localized to the thoraco-lumbar region with radiation to both lower limbs and exacerbation with motion. She had a positive Lasègue sign with no sensory disturbances, bowel or bladder disturbances or motor weaknesses and no headaches.Magnetic resonance imaging (MRI) of spine showed T1 and T2 hyper-intensity in the lumbo-sacral thecal sac suggestive of SAH ( Figures A, B, C). There was no spinal cord signal abnormality or perimedullary flow voids. There was a focal T1 and T2 hypo-intense lesion in the antero-lateral aspect of the spinal canal at the level of T12-L1 inter-vertebral disc. This lesion showed subtle eccentric nodular enhancement on post contrast T1 images. Spinal MR angiogram was negative for a shunting lesion with no prominent vessels.The differential diagnoses included: a slow flow or partially thrombosed ScAVM (despite the absence of prominent vessels); a spinal eccentric cavernoma (despite the focal contrast enhancement and the subarachnoid hemorrhage without intramedullary component); a spinal artery aneurysm, and vasculitis. A conventional spinal angiogram was recommended.Spinal angiography was performed under general anesthesia and included selective catheterization of segmental arteries T8-L4 bilaterally. The left L1 segmental artery angiogram showed the major supply to the ASA axis (radiculomedullary supply, the so-called artery of Adamkiewicz), no venous stagnation, with narrowing of the artery possibly related to vasospasm.