Lumbar caudal epidural blocks for low back and leg pain

The covering over the nerve roots in the spine is called the dura. The epidural space is a fat filled ‘sleeve’ that surrounds the dura providing cushioning for the nerves and spinal cord. Nerves from the spine travel through this epidural space before travelling to the legs. These nerves can become inflamed due to irritation from a damaged disc, bony spurs (osteophytes), ligamentous thickening and other rarer causes. Inflammation of these nerves can cause low back, hip, buttock and leg pain. Epidural steroid Injections are a method of treating inflammation associated with low back related leg pain. Cortisone placed into the epidural space has a very potent anti-inflammatory action that can decrease pain and allow patients improved function. Recent studies have shown that 60-70% of patients with leg pain due to spinal stenosis will have significant improvement in their pain for up to 6 months.

Although cortisone does not change the underlying condition, it can break the cycle of pain and inflammation and allow the body to better compensate for the condition. In this way, the injections can provide benefits that outlast the effects of the steroid itself. There are various ways of injecting cortisone into the epidural space, each with their own pros and cons. For patients with multi-level disease the caudal approach is often the best as the cortisone is able to spread over several levels. The epidural space extends all the way down to the very end of your spine. There is a small hole at the base of the sacrum (the sacral hiatus) through which the cortisone can be injected.

What to expect?

You may have some partial numbness in your buttocks or legs due to the local anaesthetic which is injected with the cortisone. You should arrange to be driven home and to take things quietly for the rest of the day. Many doctors will request you keep a daily pain diary to assist in assessing the success of the cortisone block. Take your regular medication and on the following day you may resume your regular activities (specific instructions regarding blood thinning medications and diabetes may be given by your doctor). Further follow-up will be arranged with your treating doctor.