Caudal epidural steroid injections involve injecting a steroid into the epidural space, where the irritated nerve roots are located. The caudal injection is performed through the sacral opening and is used to treat low back pain. This injection includes both a long-lasting steroid and an anesthetic (lidocaine, bupivacaine). The steroid reduces inflammation and irritation, while the anesthetic interrupts the pain-spasm cycle and nociceptor transmission (Boswell 2007). The medicines spread to the most painful levels of the spine, reducing inflammation and irritation. The entire procedure usually takes less than 15 minutes.
Radiculopathy occurs when something irritates a spinal nerve—say a “slipped disc” causing a pinched nerve. This is also called sciatica . There are resident stem and other cells in the local tissues everywhere in our body. Many live around blood vessels. These are obviously also present in the disc and nerves in the epidural space and they usually play an important role in suppressing inflammation and repairing damage. We know, based on a copious in vitro (lab) data, that the high-dose steroids used in epidural injections can kill these cells. So the progression of the series of epidural steroid injections looks a little something like this: