Case Report: Anterior Spinal Cord Ischemia Following Embolization of Cerebellar Arteriovenous Malformation: An Illustrative Case and Review of Spinal Cord Vascular Anatomy

Abstract

Spinal cord ischemia (SCI) is a rare entity with high mortality and morbidity which can arise from causes such as atherosclerosis, aortic dissection or aneurysm, thromboembolic events or systemic hypotension, and is a potential complication of spinal surgery. Published literature contains very few reports of SCI as a complication of intracranial interventions, highlighting the uncommon nature of SCI in these circumstances. We report the occurrence of anterior SCI in a 69-year-old patient following successful embolization of a cerebellar arteriovenous malformation (AVM), marked by upper extremity weakness, lower extremity paraplegia, loss of bladder and bowel control, and hypercapnic respiratory failure requiring mechanical ventilation. Magnetic resonance imaging (MRI) demonstrated upper cervical diffusion restriction and T2/STIR hyperintensity. Unusually, SCI occurred in this case without intraprocedural catheter wedging or obvious flow limitation, prolonged procedure time, hypercoagulable state, or general hypotension. We review previous cases in the literature as well as spinal cord vascular anatomy, and discuss the possible etiologies of this complication. Spinal cord ischemia could be a very rare complication of neuroendovascular procedures even in the absence of warning signs and should be carefully evaluated in patients with suspected neurologic symptoms after such procedures.

Keywords: arteriovenous malformation; embolization; spinal cord; spinal cord ischemia; stroke; vascular diseases.

Figure 1

(A) AP roadmap image of co-dominant right VA, with tortuous origin (arrow) from the subclavian artery. (B) AP roadmap of left VA origin (arrow) and proximal cervical course of the artery. The artery of cervical enlargement is also seen (arrowhead). (C) AP angiogram from a right VA injection, with opacification of the AVM nidus (arrowhead), with competitive flow from the left VA. (D,E) AP and lateral arterial phase images from a left VA injection, demonstrating the AVM nidus (arrowheads) in the superior aspect of the right cerebellar hemisphere. (F–H) Reconstruction of 3D DSA data in axial (F), Sagittal (G), and coronal (H) planes, demonstrating the AVM nidus (arrowheads).

Figure 2

(A,B) AP Roadmap images of the left VA, before (A) and after (B) advancement of the five Fr guide sheath into the mid cervical left VA, distal to the origin of the artery of cervical enlargement (arrowheads). The position of the tip of the guide sheath is marked by the arrow. (C,D) Lateral and AP views of a right superior cerebellar artery microcatheter injection, during embolization of the AVM. (E,F) Final cast of the Onyx (arrowheads) within the AVM nidus. (G,H) Final AP and lateral arterial phase images of the posterior circulation, from a left VA injection, demonstrating the residual nidus (arrows). (I,J) Lateral and AP images from the final left VA injection prior to removal of the guide sheath, demonstrating patency of the ASA (arrowheads).

Figure 3

MRI Cervical Spine, performed the day following the embolization. (A,B) Sagittal T2W images demonstrating abnormal increased T2 signal in the spinal cord (arrows). (C) Sagittal Diffusion Weighted image demonstrating abnormal diffusion restriction in the Cervical Spinal cord (arrows). (D,E) Axial GRE T2W images demonstrating abnormal increased signal in the central Gray matter, or “owls eye” sign. (F) Axial TSE T2W image demonstrating the “owls eye” sign.

Figure 4

Timeline of events post-procedure.

Figure 5

(A) AP view of right deep cervical artery (red arrow) injection demonstrating radiculomedullary feeder (black arrow) to the ASA (blue arrow). (B) Oblique view of deep cervical artery (red arrow) injection demonstrating radiculomedullary artery (black arrow) supply to the ASA (blue arrow). (C) Lateral view of VA (red arrow) injection demonstrating multiple cervical radiculomedullary feeders (black arrows) to the ASA (blue arrow). (D) AP view of left VA (red arrow) injection demonstrating multiple cervical radiculomedullary feeders (black arrows) to the ASA (blue arrow).