Epidural steroid injections are most commonly used in situations of radicular pain, which is a radiating pain that is transmitted away from the spine by an irritated spinal nerve. Irritation of a spinal nerve in the low back ( lumbar radiculopathy ), such as from lumbar spinal stenosis , cervical spinal stenosis, herniated disc , and foraminal encroachment, causes back pain that goes down the leg. Epidural injection is also used as a minimally invasive procedure to treat nerve compression in the neck (cervical spine), referred to as cervical radiculopathy , which causes pain.
To provide a better understanding of the injection procedure and the region that the medication is administered, the spinal region will first be briefly described. There are a vast number of nerves that run along the spinal cord. The nerves extend throughout the entire body and are protected by cerebrospinal fluid (CSF). The spinal cord is also stabilized by a tough membrane within the spinal column. The area that is directly outside of the membrane is referred to as the epidural space. The roots of damaged, irritated, or inflamed nerves, which are the targets for the steroid injections, are located in the epidural space.