What is Nerve Root injection for back pain?
Nerve Root Injection is a small procedure that is very useful to control back and leg pain performed under local or intravenous sedation. This nerve root injection helps to reduce the pain and inflammation due to the nerve root compression. The nerve roots that come out of the spinal cord exits through small holes (foramen) in your spine. These nerve roots can be pinched by a herniated disc, narrowing of the holes (foramen)due to wear and tear of the spine.
When is this procedure recommended by the Spine Surgeon?
Where is this injection given for back pain?
The spinal column is made of bones and the soft cushion between these bones. It has a central canal (passage) that contains and protects the solid spinal cord. There are branches coming out of the spinal cord at regular intervals on each side. These are called nerve roots. These nerve roots come out of the spinal cord exits through small holes (foramen) in your spine. These nerve roots can be pinched by either a herniated disc or by the narrowing of the small exit holes (foramen)due to wear and tear of the spine. This is also called ‘Lumbar Radiculopathy’. The nerve root injection is given close to the trapped or pinched nerve.
What does the Nerve root injection contain?
Nerve Root injection contains a mixture of:
- Kenalog 40 mgs (Steroid)
- Marcaine 0.25% (Local anaesthetic)
KENALOG is a Steroid commonly used in Spine Injections. It has a 40 mgs of steroid and works on the nerve root as it comes out of your spine and reduces pain and inflammation around your spinal nerves.
It blocks the release of chemicals that your body releases from ruptured or damaged discs and injured soft tissues around your spine. Due to the pain relief, there is more movement in the small (facet) joints and the soft tissues. This increase in movement will further reduce the stiffness around the bones, ligaments and muscles of your spine.
Marcaine 0.25% is the same local anaesthetic (numbing solution) used by your dentist. This is also used in Nerve Root Spine Injections. This solution works on the spinal nerve that comes out of your spine and reduces pain and works very well with the steroid.
It blocks the pain signals released by your irritated and inflammed spinal nerves as the steroid works to control the inflammation. The increase in movement will further reduce the stiffness around the bones, ligaments and muscles of your spine.
Omnipaque 300 is a contrast dye that helps locate the Spinal Nerve root as it comes out of the Spinal Canal. This gives an accurate location and confirms the position of the Nerve Root. This is commonly used in Nerve Root Spine Injections.
The dye on the Xray picture will show the position of the Nerve Root. This will allow the spine surgeon to place the needle in the exact position and give the injection.
This improves the safety of the procedure.
What does the injection exactly do?
Nerve root injection contains a mixture of numbing solution (local anaesthetic) and corticosteroid (steroid). The local anaesthetic will improve the pain immediately and the steroid in the solution will act on the inflammation around the nerve roots and control the ‘sciatica pain’ in the long term. This improvement in the pain will help you move around better and mobilise your lower back. This increase in the movement of the small joints of your spine will further reduce the stiffness around the bones, ligaments and muscles.
DAY CASE PROCEDURE
You will be admitted for Day Case surgery just for a day. You will need to come in starved for at least 6 hours. This is because we have to give you a sedative in your arm to make you sleep for a short duration. It will help you cope with the anxiety and pain from the procedure. Your will be required to lie on your tummy comfortably. After the sedation, your skin on the back will be cleaned with an antiseptic solution.
You will be admitted for Day Case surgery just for a day. You will arrive in the morning with a member of your family. It will be safe for you to return home after a short period of sedation.
You need to come in starved for at least 6 hours. It is safe to give you sedation in an empty stomach. It will help you cope with the anxiety and pain from the procedure.
Your will be required to lie on your tummy. After the sedation, your skin on the back will be cleaned with an antiseptic solution.
What happens during the procedure?
A spinal needle is used to inject the steroid and anaesthetic solution close to the Nerve Root. X-rays will be taken to make sure that the needle placement is accurate. Further the dye (Omnipaque 300) is injected into the space to outline the position of the Nerve Root before the anaesthetic and steroid solution is injected. You will recover from the procedure and sedation very quickly.
After the injection, you will be taken to the recovery room from theatre and monitored for an hour. You will be able to leave hospital once you are safe.
What happens after the Nerve root injection?
You must be aware that the local anaesthetic may cause a temporary numbness or weakness of the leg for a few hours. Your leg may give way when you try getting out of bed due to the weakness. But this will settle with time. Once the effect of the anaesthetic wears off, your leg and back pain may return, occasionally slightly worse than before for a short period until the steroid in the solution takes effect. It takes a few days or even weeks for the steroid to take effect on your pain.
You must continue to take your usual pain relief medication that your doctor had prescribed for you till you begin to feel benefit. Some medications like morphine, gabapentin, pregabalin or amitriptyline need to be continued and not stopped abruptly.
What are the benefits of this procedure?
70% of patient will have significant benefit from a nerve root injection for low back pain. But the duration of this pain control varies between a few weeks to a few months. Sometimes the pain relief can last for a year. The disc swelling will reduce naturally due to your increase in mobility and activity. However, there is an increased risk of having a further episode of back and leg pain.
Repeat Injections: If the initial nerve root injection was helpful in controlling your leg and back pain, you will be offered a repeat injection.
How many nerve root injections can you have?
Most experts recommend not more than 2 injections over a 12-month period. There are concerns about the adverse side effects of repeated steroid injections on the nerve root and on your metabolism. There is a very small risk of diabetes, raised blood pressure, decreased immunity, recurrent infections and weight gain.
What are the risks and complications of Nerve root injection?
INFECTION: This is rare but there is an increased risk in skin conditions like psoriasis or eczema. The rate is less than 1 in 1000 injections
BLEEDING: There is very little chance that you will bleed from a tiny puncture wound with a needle. But there is an increased risk of bleeding if you are taking medications to ‘thin your blood’ like warfarin, rivaroxaban or clopidogrel. You will be advised to stop these medications at least a week in advance of the procedure for safety.
ALLERGIC REACTION TO THE CONTRAST DYE: In rare instances, you may be allergic to the dye that is used to check the exact needle position. This happens in the range of 1in 200 to 1 in 500 injections. People who are allergic to seafood are found to be more prone to this reaction. These include skin rash, itching and flushing of the face.
HEADACHE: This happens when there is a small leakage of the fluid present around your spinal cord from the injection. This fluid usually leaks out and can cause headache while standing and walking for a few days. You will be advised to lie down flat for a few days until the headache settles.
FASCIAL FLUSHING: This is a temporary side effect from the steroid injection and settles down very quickly.
VASOVAGAL OR FAINTING EPISODE: This can be due to the stress of the procedure and is not life threatening. 1 in 100 patients do have such episodes and it settles very quickly.
When can I get back to work?
You are advised to take the next day off work as you had an intravenous sedation. If your back pain persists or is worse, you may need a few days off work. Usually, it can take several weeks before you feel the full benefit of the caudal epidural injection. There are no limitations for work if your pain settles after a day.
When is my follow up appointment?
This is booked in 4 weeks after the injection. It allows you to explain the progress of you back and leg pain to Mr Rajesh and he may arrange physiotherapy to build on the gains from the injection. Repeat injections or possible the need for surgery only if necessary, can be discussed.