A middle-aged male with a history of hypertension, hyperlipidaemia, and type-2 diabetes mellitus presented with a 6-month history of progressively worsening unsteady gait and lower limb paresthesia. Nerve conduction studies showed no evidence of a large fibre polyneuropathy. Contrast-enhanced MRI of the spine showed long-segment central T2-weighted and STIR hyperintensity extending from the T7 to T12 level with expansion of the cord and mild contrast enhancement. Lumbar puncture showed no evidence of pleocytosis, elevated CSF protein, malignant cells, or CSF-restricted oligoclonal bands. A metabolic screen (Vitamin B12, Vitamin E, Copper, Zinc) was normal. Contrasted MRI of the brain showed no intracranial abnormalities and anti-myelin oligodendrocyte and anti-aquaporin-4 antibodies were negative. Autoimmune serologies as well as infective workup (HIV, human T-lymphocyte virus, Syphilis, Cytomegalovirus) were negative. Further review of MRI imaging identified subtle flow voids on the cord surface on the T2 STIR sequences. A spinal angiogram identified a spinal dural arteriovenous fistula (SDAVF) arising from the radiculomedullary and radiculomeningeal arteries of the T10 segmental artery, with the artery of Adamkewicz arising from the same segmental artery. Surgical resection was offered over embolization due to the proximity of the artery of Adamkewicz and the patient subsequently underwent a successful ligation of the T10 SDAVF.

SDAVF may present with radiological features of longitudinally extensive transverse myelitis due to venous hypertension and cord edema and may mimic autoimmune causes of myelopathy. The presence of serpiginous intradural extramedullary flow voids on T2 sequences may raise suspicion of an underlying SDAVF, which should be confirmed on spinal angiography. Treatment includes endovascular occlusion or surgical ligation. Endovascular treatment is contraindicated if the radicular artery also supplies the anterior spinal artery due to risks of cord ischemia. If treated early, motor and sensory function can be improved or stabilized in most cases.