Thoracolumbar progressive myelopathy due to extra-dural arteriovenous fistula
Context: Arteriovenous dural fistulas are the most common spinal vascular malformations and constitute a reversible cause of progressive myelopathy. This disease affects elderly men and are classically found at the thoracolumbar region. Case report: A 69year-old man was admitted to the Neurology outpatient clinic with weakness in his left inferior limb for the past 10 years; 2 years before the evaluation, the weakness progressed also to the right inferior limb, causing inability to walk, and 1 year after the patient noticed urinary incontinence and sexual dysfunction. Physical evaluation showed grade-II paraparesis with spastic hypertonia; hypoesthesia below T-10 dermatome; hyperreflexia with clonus and Babinski sign in inferior limbs. Investigation with MRI showed abnormal hypersignal within spinal cord from T6-T7 to the medullary cone; CSF sample had hyper protein count without pleocytosis. Before the hypothesis of non- compressive, non-inflammatory and non-infectious myelopathy, we performed a spinal angiography – which diagnosed a dural arteriovenous fistula at the level of T8 connecting spinal with extradural vessels. The patient was then treated by endovascular therapy with fistula embolization. Conclusion: Although being the most common vascular spinal malformation, arteriovenous dural fistulas are rare and underdiagnosed because of their nonspecific symptoms. The aim of treatment is the shunt occlusion but its prognosis depends on the duration and intensity of symptoms before treatment. This report’s aim is to exemplify a typical case of this condition.