What Is The Epidural Space?
The dura is a protective covering of the spinal cord and its nerves. The space surrounding the dura is called the epidural space. In the upper back, it is called the thoracic epidural space.
What Causes Pain In Epidural Space?
The thoracic area of the spine has twelve bones, called vertebrae. Soft discs found between them cushion them, hold them together, and control motion.
If a disc tears, chemicals inside may leak out. This can inflame the dura or nerve roots and cause pain.
A large disc tear may cause a disc to bulge, inflaming the dura and nerve roots, and cause pain. Bone spurs, called osteophytes, can also press against nerve roots and cause pain.
How Do I Know If I Have Disc And Nerve Root Pain?
If you have pain in your upper back when you move, you may have disc or dural inflammation. If pain travels to the front of your chest when you move your upper back, you may have nerve root inflammation.
Common tests such as MRIs can show disc bulges and nerve root compression, but may not show a torn and leaking disc. A thoracic epidural injection can help find out if disc, dural, or nerve root inflammation is causing your pain.
What Is A Thoracic Epidural Steroid Injection?
In a thoracic epidural injection a local anesthetic (numbing medicine) and a corticosteroid (antiinflammatory medicine) are injected into the epidural space to reduce inflammation. It may be done from the back. This is called an interlaminer injection. Other times it is done from the side. This is called a transforaminal injection. If the needle is positioned next to an individual nerve root, it is called a selective nerve root block.
What Happens During An Injection?
A local anesthetic may be used to numb your skin. The doctor will then insert a thin needle directly into the epidural space. Fluoroscopy, a type of x-ray, may be used to ensure the safe and proper position of the needle. A dye may also be injected to make sure the needle is at the correct spot.
Once the doctor is sure the needle is correctly placed, an anesthetic and steroid will be injected.
What Happens After An Injection?
You will be monitored for up to 30 minutes after the injection. When you are ready to leave, the clinic will give you discharge instructions.
You will also be given a pain diary. It is important to fill this out because it helps your doctor know how the injection is working.
It may help to move your upper and mid back in ways that hurt before the injection, to see if the pain is still there, but do not overdo it. Take it easy for the rest of the day.
You may feel immediate pain relief and numbness in your upper and mid back and leg for up to six hours after the injection. This tells you the medication has reached the right spot.
Your pain may return after this short pain-free period, or may even be a little worse for a day or two. This is normal. It may be caused by needle irritation or by the steroid itself. Steroids usually take two or three days to start working, but can take as long as a week.
You can usually return to work the day after the injection, but always check with your doctor.
How Long Can I Expect Pain Relief?
How long you can expect pain relief depends on the amount of inflammation.
Sometimes an injection brings several months of pain relief, and then further treatment is needed. Other times, a single injection brings long-term pain relief. If your pain is caused by injury to more than one area, only some of your symptoms will be helped by one injection.