Dorsal Root Ganglion Block / Nerve Root Block / Transforaminal Injection

Patient Experience

  • Reference Number: HEY-678/2023
  • Departments: Pain Medicine
  • Last Updated: 1 March 2023


This leaflet has been produced to give you general information about your treatment.  This leaflet should have answered most of your questions.  It is not intended to replace the discussion between you and your doctor but may act as a starting point for discussion.  If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team caring for you.

What is a dorsal root ganglion block / nerve root block / transforaminal injection?

The nerves that carry sensation come out of the spinal cord and branch out to the different parts of the body. The dorsal root ganglion looks like a small swelling on the nerve where it joins the spinal cord.  It is here that impulses from the nerves are transmitted through to the spinal cord.  Local anaesthetic can be injected into the dorsal root ganglion to slow down or block nerve impulses. Although this may help your pain initially, the effect will wear off.

Why do I need a dorsal root ganglion block / nerve root block / transforaminal injection?

A dorsal root ganglion block / nerve root block / transforaminal injection may be a test to determine the source of your pain and / or to relieve your pain.  If you get a period of sustained pain relief from the injection, it will help the doctor decide which procedure to do next.

Can there be any complications or risks?

Some patients experience mild local tenderness at the site of the injection. This usually settles over the next few days following the injection.

Very rarely, the local anaesthetic may spread causing some numbness in your legs and other areas. This is temporary and will resolve after a short period of time. If you experience numbness affecting your bladder or bowel habits after the procedure, or numbness in legs, you should speak to your GP or attend Urgent Care. You will be asked to remain in the department until you have been assessed by the medical team and full sensation has returned.

There is also a small risk of allergic reaction to the contrast (X-ray dye) used to confirm the exact location of the needle.  The steroid drug sometimes used in the injection can occasionally cause such problems as diahorrea and abdominal pain; this will resolve after a short period of time, however if it continues, consult your GP. The steroid can also cause flushing and redness to the face, which also will pass after a short period of time.

Other risks could include an increase in pain, infection, bruising, bleeding or nerve damage

Advice to be read before having a pain relief procedure

The following information has been produced to ensure that you are able to have your pain relief procedure.  It is essential that you read and follow the advice given below before you come to the hospital. If you do not follow the advice you may not be able to have your treatment.

Please contact the Pain Service if any of the following apply to you:

  • You are diabetic and take medication to control your diabetes. (See below on how to manage treatment sessions booked for the morning or the afternoon)
  • You have recently had an admission to hospital.
  • You have tested positive for MRSA.
  • You have an infection and are currently taking antibiotics.
  • If there is any possibility you may be pregnant.

Continue your other regular medications including your pain relief. However, if you take any of the anticoagulants listed below, please notify the Pain Service at least 10 days before your appointment. You will need to stop taking these drugs at least 1 week prior to the procedure unless your doctor has advised against this.

  • Warfarin (Marevan)
  • Clopidogrel (Plavix)
  • Dipyridamole (Persantin Retard)
  • Phenindione
  • Pradaxa
  • Xarelto
  • Sinthrome
  • Asasantin Retard

You may have to wait a while before your procedure, so please bring something to read or do to keep yourself occupied.

Please leave any valuables or jewellery at home.  It is essential that after the procedure you arrange for an adult friend or relative to collect you by car or taxi. You will not be able to use the bus or train to travel home.

Hospital transport may be available if there is a medical need. If you think you may be eligible, please contact the Pain Service.

Sometimes nerve blocks are done under sedation (a drug is given to make you drowsy and relaxed but still conscious). You should not have anything to eat on the morning of your treatment, however you may have a drink (tea or coffee without milk) if you wish, up to 2 hours before your appointment time.

Advice for diabetic patients only

If you are diabetic and booked to attend treatment in the morning, you should not have breakfast or morning medication but bring the medication with you.

If you are booked for treatment in the afternoon, please have your breakfast and take regular medications before 7.00am. Thereafter only drink clear fluids (not milk) for up to 2 hours before the procedure.  Please inform the Pain Service staff as soon as you arrive that you are diabetic, the staff will then assess your diabetes and if necessary, take appropriate action to monitor and control your blood sugar while you are in our care.

What happens before the procedure?

You will be admitted by the nursing staff who will ask for and record some information about you.  Your blood pressure will be checked and you will be given a gown to put on. The doctor will explain the procedure and ask you to sign a consent form.  Please make sure you have understood what has been said and feel free to ask any questions.

What to expect during the procedure

As a precautionary measure, a thin plastic tube (cannula) may be inserted into a vein in your arm/hand.

After cleaning your back with antiseptic solution, local anaesthetic will be injected into your skin to numb it.  Under X-ray screening, a fine needle is introduced into your back towards the area to be treated.  A small dose of contrast (X-ray dye) will be used to confirm the exact location of the needle.  Once the optimal position is obtained, local anaesthetic with or without steroid will be injected close to the nerve.  The number of injections will depend upon the number of affected joints.

What happens after the procedure?

You will be taken on the trolley to the recovery area where the nurse will check your blood pressure and pulse.  You will be asked to rest for about an hour.  After that you will be able to get up, but please check with the nurse before you do so.

Once you are mobile, you will able to go home accompanied by an adult friend or relative.

Please ensure that you have arranged for someone to drive you home after this procedure.  Failure to do so will result in your procedure being cancelled.  If you have had sedation, we recommend that you arrange for someone to stay with you overnight and that you do not drive for 24 hours.

What to expect when you return home

Take it gently for a few days but gradually build up your activities. You should continue to take all your usual medication/pain relief as the pain may be slightly worse until the nerve block starts to work.

Some people find that they get relief from their pain but, after a couple of months this wears off.  Others may experience complete relief; however, there is a chance that the pain will not improve, not change or will get worse.

During the reduced pain period you should try to gently increase your exercise. Simple activities like a daily walk, using an exercise bike or swimming on your back will help to improve your muscle tone and strengthen your back. The best way is to increase your activity slowly.

Try not to overdo things on a good day as this may result in you experiencing more pain the following day.

How long will the pain relief last?

This is highly variable between the individuals.  Some might notice immediate pain relief where in others it may take up to one to two weeks.  However, pain relief may last from a few days to several months.  Some patients do not get any pain relief from nerve blocks.

Follow up appointment

A letter will be sent to your doctor and you will be reviewed either by telephone or seen at the Pain Service in due course.

Points to remember

You will need to have arranged for someone to drive you home after this procedure.

  • Please bring your glasses if you need them for reading.
  • Always bring a list of all current medication.
  • Continue taking all your usual medication on treatment day (see advice if you are a diabetic patient)
  • If there is any possibility you may be pregnant please inform the doctor or nurse.

Additional information

If you experience unusual symptoms such as a marked increase in pain around an injection site, fever, severe headache, new symptoms of pins and needles, new muscle weakness in your arms and legs, or you are very concerned about how you feel after the procedure, please contact your GP or go to an Urgent Care Centre.

In the event of an emergency and outside normal working hours of the Pain Service (9am – 4pm,) please contact your own GP or your local Emergency Department.

General Advice and Consent

Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.

Consent to treatment

Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.

The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:

  • you must be able to give your consent
  • you must be given enough information to enable you to make a decision
  • you must be acting under your own free will and not under the strong influence of another person

Information about you

We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.

We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.

Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.

If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.

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