Spinal subarachnoid hemorrhage as a consequence of dissection with pseudoaneurysm in a cervical radiculomedullary branch of the anterior spinal artery

Spinal subarachnoid hemorrhage is a rare condition, and it generally arises as a consequence of arteriovenous malformation, although more rarely can be caused by aneurysm, dissection, or pseudoaneurysm. In the following, we present a case of a 58-year-old male who while undergoing treatment for nephrolithiasis, developed persistent hypertension, refractory to his home medications, along with headache, neck pain, and unilateral ptosis and upper extremity ataxia. Initial CT scan demonstrated acute subarachnoid hemorrhage in the posterior fossa extending to the C7 level, Angiography ultimately revealed a focal irregularity compatible with dissection and 1mm pseudoaneurysm within the left anterior spinal artery radiculomedullary feeder at the C5-6 level. The patient was managed conservatively with 81mg ASA and repeat angiography revealed resolution of the lesion, in concordance with management of dissection and pseudoaneurysm of the carotid and vertebral arteries. Subarachnoid hemorrhage as a consequence of dissection and pseudoaneurysm of a cervical radiculomedullary feeder has been previously unreported in the literature.