Before the injection procedure begins, topical anesthesia is applied to the skin. Next, in order to prevent healthy nerve roots from being exposed to too much medication, the physician will use imaging technology such as fluoroscopy to guide the insertion of the needle and to confirm its correct placement in the epidural space. In addition, contrast dye is typically injected in order to observe where the medication will be administered and to ensure that it will be properly distributed throughout the targets areas. The administration of steroids and an anesthetic such as Lidocaine directly onto the nerves roots results in dramatic or complete pain relief. The steroid decreases inflammation, while the anesthetic disrupts pain signal transmission.
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.