RESUMEN
The purpose of this article is to present a case of cauda equina syndrome in a patient with incomplete motor and sensory deficits due to epidural venous plexus engorgement, owing to May-Thurner syndrome successfully treated with venous iliac stenting. A 40-year-old woman, with previous history of deep vein thrombosis and miscarriages, gradually developed right leg and back pain, with functional limitation, perineal hypoesthesia, and sphincter incontinence. Magnetic resonance imaging revealed epidural venous plexus engorgement and cauda equina roots involvement. Phlebography showed perimedullary venous enlargement and left common iliac vein stenosis, leading to the diagnosis of May-Thurner syndrome. Stenting of the left common iliac vein was performed resulting in pain improvement and disappearance of neurological symptoms. Thrombophilia study was positive to heterozygous factor V Leiden. Cauda equina syndrome as the first presentation of a May-Thurner syndrome is very rare. In this case, venous iliac stent placement was an effective and safe treatment.