Spontaneous resolution of an isolated cervical anterior spinal artery aneurysm after subarachnoid hemorrhage.

Background: Isolated cervical anterior spinal artery aneurysms are extremely rare. Subarachnoid hemorrhage (SAH) secondary to such lesions have been described only in six cases to the best of our knowledge.

Case Description: We describe an unusual clinical picture of SAH due to rupture of anterior spinal artery aneurysm in a patient with previous normal angiogram. Due to the location of the aneurysm and clinical status of the patient, conservative management was proposed, and she was discharged to further follow-up. Monthly routine angiograms revealed resolution of the aneurysm 90 days after bleeding, which was highly suggestive of vascular dissection.

Conclusion: We highlight the need to consider these aneurysms in the differential diagnosis of SAH, especially when occurring in the posterior fossa and when angiography findings are inconclusive.