Let's learn more about the Epidural Injection for back pain (Epidural Steroid Injection - ESI)

Do you sometimes get a sharp pain that shoots down your back like an electric shock? Or do you constantly suffer from pain that radiates from your neck down your arm? It's really hard to live with this kind of pain. When things like physiotherapy and medication don't work, one treatment that doctors recommend is an 'Epidural Steroid Injection' (ESI). Many people are a little afraid of this. So, let's talk about it all simply and clearly today.

Simply put, what is an 'Epidural Steroid Injection' (ESI)?

This is also a type of injection. But this time, you don't get a regular painkiller. Instead, you get a special medicine that reduces swelling and inflammation, called a steroid (a `corticosteroid`) , injected into the space where the nerves are located in your spine (the `epidural space`).

Think of our spinal cord as a major highway that carries messages from the brain to the rest of our body. The safe space around this route is what we call the `epidural space.` When a nerve that runs along this route becomes irritated or inflamed for some reason, severe pain occurs. What ESI does is inject a drug into the inflamed nerve, reducing the swelling and giving you relief.

How does this injection reduce pain?

Our spine is made up of small bones (vertebrae) that are connected to each other. Between these two bones is a jelly-like 'disc'. This is what gives the spine its flexibility and protection.

Sometimes, a herniated disc (a herniated disc or bulging disc) can pinch a nearby nerve. Or, the nerve can also be pinched due to a narrowing of the space inside the spine (spinal stenosis). When a nerve is pinched in this way, it swells and becomes inflamed, causing pain.

ESI involves injecting a steroid around the inflamed, pinched nerve. This reduces the swelling and inflammation and relieves the pressure on the nerve. This gives the nerve time to heal. Some people experience pain relief for a few weeks, while others may experience months. Sometimes, this injection can also help identify the exact cause of the pain.

For what conditions is an ESI injection recommended?

A doctor usually recommends an ESI when other treatments have failed to control pain. The table below explains this further.

Types of ESI Injection

There are several types of ESI injections. They are divided according to the location of the injection (neck, mid-back, lower back) and the method of needle insertion.

• Categories by location:
• Cervical ESI: For pain that radiates from the neck down the arm.
• Thoracic ESI: For upper and middle back pain.
• Lumbar ESI: For pain that radiates from the back down the leg (this is the most common).

• Types according to the method of needle insertion:
• Interlaminar ESI: Inserting a needle between two vertebrae and injecting medicine.
• Transforaminal ESI: The injection is made through the hole (`foramen`) where the nerve exits the spinal cord, right next to the pinched nerve.
• Caudal ESI: Inserting the needle through a hole at the lowest end of the spinal cord.

Your doctor will decide which type is best for you.

How should I prepare before the injection?

Your doctor will give you some special instructions before the injection. It is very important to follow them exactly.

• If you are pregnant or suspect you may be pregnant , be sure to tell your doctor.
• Tell your doctor about all the medications you take (especially blood thinners ) . He or she may ask you to stop taking them for a few days.
• You may be asked to fast for a few hours before the injection.
• Sometimes, an MRI or CT scan may be ordered to determine the exact cause of the pain.
• You will be asked to bring someone home with you on the day of the injection, as sometimes a sedative may be given to help you relax.

What actually happens when the injection is given?

This is usually done in a hospital or clinic. The entire process takes about 15-30 minutes.

1. First, you will be turned onto your stomach on a bed and made to lie down.

2. Then the doctor thoroughly cleans the injection site and applies an antiseptic.

3. Next, a small needle will numb the area. This way, you won't feel much pain when the larger needle injects the medicine.

4. Then, using something like an X-ray machine (`Fluoroscopy`) , the needle is guided into the exact location (`epidural space`). It is very important that you remain still during this time.

5. Once the needle is in the correct position, a liquid called contrast is sometimes injected and the spread of the medicine is monitored on a screen.

6. Finally, the steroid medication will be injected into the vein. At this time, you may feel a slight tingling or prickling sensation. This is normal.

7. After the injection, a piece of cotton will be placed on the area and a plaster will be applied. After that, you will be asked to rest for a while and sent home if there are no problems.

Are there any side effects and risks after the injection?

As with any medical treatment, there are minor side effects and very rare serious risks.

What are the symptoms that require immediate medical attention?

If you experience any of the symptoms below when you get home after the injection, call your doctor immediately or go to the nearest hospital Emergency Department (ETU).

• A severe headache that comes on when you stand up or sit down (this subsides when you lie down).
• Fever or stiff neck.
• Inability to control urine or stool.
• Feeling of numbness or weakness in the legs .

Don't ignore these symptoms.

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