Patients who have severe back pain and who have a damaged nerve - with weak muscles and numb areas of skin - may benefit if an anesthetic injection is given into the epidural space in the spine. This type of injection seems particularly useful for patients who have prolapsed discs producing nerve pain that has not responded to any other sort of treatment.

This injection is given into the space between the bony outer walls of the spinal canal and the membrane which covers the spinal cord, and in addition to containing an anesthetic the injection usually contains a steroid. The anesthetic numbs the spinal cord and the steroid helps to reduce the amount of local inflammation which has been caused by the prolapsed disc.

The pain relief produced by an epidural injection may be temporary or permanent, and about half of all patients get at least some relief. The procedure is fairly uncomfortable but the relief can be tremendous.