What is the epidural space and what causes pain in that area?
Dura mater is a protective layer that covers the spinal cord and its nerves. The space that surrounds it is called the “epidural space”. In the lower back, it is known as lumbar epidural space.
The lumbar area of the dorsal medulla has 5 bones, called vertebrae. Between each one of them there are some soft discs that serve as protection, keep them together and control the movement. If a disc is torn, the chemical products that lie inside could get out causing inflammation of the dura mater and the nerve roots, which produces severe pain.
If you have pain in your lower back when you bend it, it may be due to an inflammation of the dura or lumbar discs, if the pain reaches your leg when you bend your back, it may be due to inflammation of the nerve root.
What is the selective nerve roots block?
In a lumbar epidural injection, an analgesic and a steroid are applied together directly in the epidural space to reduce inflammation. If the needle is placed next to an individual nerve root, the procedure is known as a selective nerve root block. This technique involves introducing the medication directly along the inflamed nerve root.
About the procedure
The injection may begin with the administration of intravenous medication to help you relax. We can also apply a local analgesic in order to numb the skin.
The doctor will then insert a thin needle directly into the epidural space. Fluoroscopy, a kind of x-ray helps us to ensure safe and accurate needle placement. It is also possible to inject a dye to ensure it is in the right place.
Once the doctor is completely sure that the needle is in the right place, he injects the analgesic and steroid.
After the injection
You must remain under medical observation for a maximum of half an hour.
You may feel immediate relief and numbness in the lower back and leg that could last up to 6 hours. This indicates that the medicine reached the right place.
It is normal that after this brief period of relief the pain returns and it is even likely that for a day or two it will feel stronger. This may be due to irritation caused by the needle or by the steroid itself. Steroids usually take two to three days to begin to take effect, but it may take up to a week.
How effective is it?
The effectiveness of the treatment depends on the degree of inflammation. Sometimes, the injection provides relief for several months, and then the patient might need more doses. On other occasions, a single injection achieves long-term relief. If the cause of the pain is a lesion located in more than one area, an injection will eliminate only some of the symptoms.
At the London Spine Unit, we have some of the best specialists to perform nerve root block. Book a consultation to get a checkup.