[Clinical presentation of a dorsal epidural arachnoid cyst after an epidural anesthesia].

Background: Arachnoid cysts are dural diverticula with liquid content similar to cerebrospinal fluid, with 1% occurring in the spinal cord. They locate mainly in the dorsal region of the thoracic spine, and are unusual causes of spinal cord compression.

Clinical Case: The case is presented of a previously healthy 15-year-old boy, with a 20-month history of spastic paraparesis that started apparently after epidural block for ankle osteosynthesis.