CT Guided Lumbar Nerve Root Injection

What is a CT Guided Lumbar Nerve Root Injection?

A lumbar nerve root block is requested for pain that is caused by an irritated nerve root.
The aim of the procedure is to reduce the inflammation of the nerve root and to block the pain impulse. This will then bring partial or complete (but temporary) relief of the pain. This is achieved by injecting a steroid and long acting analgesia (pain killer) around the nerve root. It is difficult to predict how much relief you will experience after having the injection. Unfortunately some patients experience little or no benefit.

How do I get ready for a CT Guided Lumbar Nerve Root Injection?

You can eat, drink and take most medication normally.
If you are taking any anticoagulant medication (blood-thinners) other than Aspirin, then please call the department on 020 7288 5888 at least 1 week prior to your appointment for advice.
Please also inform us if you are taking Ritonavir (Norvir).

Are there any risks?

As with any procedure there are some small risks to consider. These are:

  • Small risk of infection (due to the needle being inserted into the skin – the procedure is carried out using the aseptic technique mentioned)
  • Haematoma occurring (bruising)
  • Nerve damage
  • Tingling or numbness in the legs or toes
  • Injury to small blood vessels

Are there any precautions?

If you are diabetic you should monitor your blood sugar more often than usual in the days following the procedure.
This is because steroids can increase blood sugar levels and your usual medication or controlled diet may not be as effective. If your blood sugar levels are high contact your GP immediately for advice.

What happens during a CT Guided Lumbar Nerve Root Injection?

On arrival please book in at the main reception of the Imaging Department on Level 3.
  • You will be asked to change into a hospital gown
  • You will be seen by the radiologist (specialist doctor) who will explain the procedure. Please ask any questions you may have about this procedure. The doctor will then ask you to sign the consent form. It is a good idea to write down any questions you have and bring them with you to your appointment
  • The procedure is undertaken using an aseptic technique; to prevent an infection occurring
  • You will be asked to lie on your stomach on the CT bed – the radiographer will position you as comfortably as possible and a CT scan will be taken
  • The area for the lumbar nerve root injection will be marked on your skin
  • The radiologist will clean the skin with an antiseptic solution and the area covered with a sterile drape. A local anaesthetic will be injected to minimise any discomfort
  • A thin needle is then positioned near the nerve root ending using CT guidance (you should not feel any pain only a ‘pushing’ sensation), and the injection of the steroid and long acting analgesic are injected through the needle
  • Once the injection is complete, the needle will be removed and a dressing will be applied to the area, this can be removed after 48 hours.

What happens after a CT Guided Lumbar Nerve Root Injection?

Usually you can leave the department immediately after the procedure. You should have someone to take you home after this procedure.
Page last updated: 17 Feb 2021
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