Postoperative reversible deterioration in a spinal dural arteriovenous fistula

This 61-year-old man presented with weakness and sensory disturbance in the legs. There was a spinal dural arteriovenous fistula (SDAVF) fed by the left sixth intercostal artery with dorsal perimedullary drainage. Surgical division of the perimedullary drainage led to rapid neurological improvement. However, on the second postoperative day he experienced transient deterioration of second neuron function in the left upper lumbar segment resulting in motor weakness of the proximal leg muscles, absence of the patellar deep tendon reflex and thigh pain. No radiological findings explaining this deterioration were obtained. He was treated conservatively and all segmental symptoms and signs subsided by the fifth postoperative day. Although the precise mechanisms underlying the dramatic but often reversible deterioration after radical SDAVF treatment remain to be determined, we postulate that this was attributable to postoperative segmental venous hemodynamic changes based on the neurological changes.