Nerve root block injections, transforaminal epidural, and dorsal root ganglion blocks: The Kent Centre for Pain Medicine and Neuromodulation
Information for patients
This leaflet explains what the following injections are:
nerve root block injections
transforaminal epidural; and
dorsal root ganglion blocks.
If you have any questions, please ask your GP or other relevant health professionals.
What is a nerve root?
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The nerve roots are found in the side of the spine. They carry messages between the body and spine, before merging with other nerves to continue up to the brain. They are the first part of the nerve that leaves the spine through small holes (called foramina).
The dorsal root ganglion looks like a small swelling on the nerve that joins the spinal cord. This ganglion contains nerves that carry sensation.
The procedure is sometimes called a transforaminal epidural, as the injection may spread to the epidural space. It is also called a nerve root block injection.
What is a disc bulge?
A spinal disc sits between each spinal vertebral bone within the spine. The disc acts as a cushion. A bulging disc extends outside the space it should occupy. Sometimes, a crack in the tough outer layer of cartilage allows some of the soft centre to protrude out of the disc. These discs are called herniated, ruptured, protruded, or slipped.
What are the symptoms?
Sometimes a nerve root can become irritated or pinched in the area where it exits the spine. Causes include a protruding disc or degenerative joints. This can result in problems in the leg, including pain, weakness, pins and needles, and numbness.
With this type of problem, patients usually have more pain in their leg than in their back.
What is a nerve root block, transforaminal epidural, or dorsal root ganglion block?
This is a method of treating leg pain that starts in the nerve roots. It is not a cure, but may offer temporary relief from your pain. Some people can get significant and lasting pain relief from these injections.
The doctor injects a local anaesthetic and / or steroid into or around the nerve roots. This may reduce inflammation and pain.
How will this injection help?
The body can absorb a high number of disc bulges on its own. The aim of this procedure is to provide pain relief for your leg pain while this occurs. If you experience pain relief from the injection, you have the chance for rehabilitation. This allows you to increase activity, exercise, or physiotherapy. The injection is not always helpful on its own.
What happens during my procedure?
The procedure is carried out as a day case (you can go home on the same day). It is performed in Day Surgery to minimise your risk of getting an infection. Shortly before your procedure we will ask you to change into a theatre gown.
The procedure is carried out under x-ray guidance. This allows your doctor to inject you accurately. Please tell your consultant if you might be pregnant. X-rays may harm your baby.
We will ask you to lie down on your front. Your doctor will clean the area with an antiseptic solution, which can feel cold.
We may place a cannula (a small flexible tube) in the back of your hand or arm. We may give you something to make you sleepy.
Your doctor will inject a local anaesthetic at the site of the procedure. This may sting to start with, before your skin goes numb.
It is important that you keep still during your procedure. The doctor will carefully insert a special hollow needle into the correct position.
You might feel pressure, tightness or a pushing sensation as the injections are made. If there is any discomfort, let the doctor know.
The doctor may repeat the injections at different levels on your spine
What are the possible side effects?
There may be some pain, bruising, and / or bleeding at the needle site.
You may feel a little unsteady when you first stand.
The procedure may make your pain worse. This should settle within one month.
There is a small risk of infection at the site of your injections. This may need antibiotic treatment. If there is warmth, redness, or tenderness at your injection sites, or you feel hot and unwell, you should contact your GP or call NHS 111 .
You may have some leg weakness or numbness, which should settle within a few hours.
Very rarely, there is a risk of temporary or permanent nerve damage.
If steroids are used:
Female patients may have temporary irregular periods.
Diabetic patients may have unstable blood sugar levels.
Rarely, some patients may have mood changes.
What will happen after my injections?
A small dressing will cover the injection site. You can remove this after 24 hours. Do not worry if it falls off sooner.
You will be discharged home 1 to 2 hours after your procedure.
You must not drive for 24 hours following your procedure. Please arrange for someone to drive you home from the hospital. We also strongly recommend that you have someone stay at home with you until the following day.
You may notice an immediate improvement, but this improvement can take a few days. Sometimes there may be a slight increase in pain for 24 to 48 hours. Steroids work slowly. Even if your procedure has worked well, nothing may seem to happen for a week or two.
Will I need a follow-up appointment?
We will arrange for a nurse to call you about 6 to 8 weeks after your procedure. We will send you a letter with the date and time of this appointment. During your telephone appointment., the nurse will review the outcome of your procedure. They will plan what happens next and discuss this with you.
If you continue to have good benefit from the procedure, you may be discharged from the Pain Clinic.
Further information
If you have any concerns about the information in this leaflet or your procedure, please phone the Pain Clinic.
Kent Centre for Pain Medicine and Neuromodulation (direct lines)
Kent and Canterbury Hospital, Canterbury
Telephone: 01227 783049Queen Elizabeth the Queen Mother (QEQM) Hospital, Margate
Telephone: 01843 235094William Harvey Hospital, Ashford
Telephone: 01233 616691