Spinal Dural AVF Two Cases with MRI Follow-up

Spinal dural arteriovenous fistula (d-AVF) is one of the arteriovenous malformations that are treatable by surgery or embolization. We present two cases treated by embolization and stress the necessity of early diagnosis and treatment, and the usefulness of T2WI on MRI for follow-up after embolization. One was a 51-year-old man who presented with gait disturbance and sphincter dysfunction. MRI revealed diffuse swelling on T1WI, and intramedullary high signal intensity on T2WI. A spinal d-AVF was found through tiny radicullomeningeal arteries via the right Th12 intercostal artery that drained into engorged retromedullary veins. The spinal d-AVF was embolized with 50% NBCA. Six months after the embolization, he was able to go back to his job, T2WI showed disappearance of the high signal intensity, which was confirmed at angiography one year after the embolization. The other case was a 62-year-old man who presented with sensory disturbance and gait disturbance. MRI showed the same findings, without the flow voids on them in case 1. The high signal area in the central spinal cord was thought to be syringomyelia, in which a syrinx-subarachnoid shunt was tried in vain. On the surface of the spinal cord, abnormally engorged and tortuous vessels were found. The syrinx was not confirmed. An angiogram showed a spinal d-AVF fed by the radicullomeningeal artery through a common trunk of the Th11/12 intercostal arteries with drainage into the retromedullary vein. The spinal d-AVF was embolized. Six months after the embolization, T2WI showed a decrease of high intensity areas. Early diagnosis and treatment are important for the prognosis of spinal d-AVF. T2WI may be the best way to check for recurrence.