Presentation
8 weeks lower limb numbness.
Patient Data
Distal cord hyperintensity and subtle expansion extend from T11 to conus at L1. On high resolution T2 images and post contrast T1 sequences, a tangle of abnormal flow voids and enhancing vessels can be appreciated posterior to the distal cord.
TRICKS MRA confirms the presence of a tangle of abnormal vessels overlying the cord, fed by a left T12 artery.
Findings are consistent with spinal dural AVF.
Spinal angiography was performed to confirm the diagnosis of spinal dural AVF.
Spinal dural AVF was identified at left T12 injection, with the fistula underneath the pedicle and a draining vein passing superiorly to a small tangle of vessels overlying the cord.
Case Discussion
Spinal dural arteriovenous fistula typically occurs in men between the ages of 40 and 60 years with a progressive subacute clinical course. The progressive myelopathy is related to venous congestion or arterial steal syndrome.
MR imaging findings of prominent vascular flow voids and numerous enhancing vessels suggest the diagnosis of arteriovenous malformation, which can be confirmed by spinal angiography. Cord expansion and T2 hyperintensity related to venous congestion and ischemia are common and may be associated with diffuse enhancement. Additional findings may be siderosis or intramedullary foci of T2-hypointense hemosiderin related to previous hemorrhage. Contrast-enhanced MR angiography is useful in identifying the level of the lesion and may facilitate spinal digital subtraction angiography, which remains the gold standard.