A rare disorder that usually is a surgical emergency. In patients with cauda equina syndrome, something compresses on the spinal nerve roots. You may need fast treatment to prevent lasting damage leading to incontinence and possibly permanent paralysis of the legs. CES affects a bundle of nerve roots called cauda equina (Latin for horse’s tail). These nerves are located at the lower end of the spinal cord in the lumbar spine. They send and receive messages to and from your legs, feet, and pelvic organs.