What is a nerve root injection?

Nerve roots are the parts of the nerves that emerge from the spinal cord. Conditions such as prolapsed discs can cause inflammation and irritation of the nerve roots. This may result in considerable pain in the spine and along the nerve into the arms.

The injection used for this procedure is a steroid (anti-inflammatory) medication. Local anaesthetic may also be used. The injection is intended to relieve pain by decreasing inflammation associated with the irritated nerve.

Patient preparation

Please inform us if you are taking any blood- thinning medication (i.e. Aspirin, Warfarin, Dabigatran or Clopidogrel) or if you have any allergies. You may need to have a blood clotting test before the procedure and have your medication adjusted by your doctor.

You will need to fast for two hours prior to the procedure.

Please advise the radiographer if you are, or think you may be pregnant.

What will happen during the examination?

You will be asked to change into a gown and to lie face down on the CT examination table. Your skin will be cleansed around the area of interest to create sterile conditions. Local anaesthetic is injected into the skin. CT imaging is used to accurately locate the area to be injected and to guide the needle. It is important you keep as still as possible during the procedure.

A radiologist (specialist medical imaging doctor) will then use CT imaging to guide the needle into position near the nerve root and inject the steroid and local anaesthetic solution. The needle is removed and a sterile dressing applied.

For some people, due to increased pressure, injection of fluid into the nerve root canal can be uncomfortable. You may experience pain radiating into your legs whilst this happens.

Are there any risks?

You will receive a small dose of x-ray radiation.

There is a small risk (1 in 20,000) of nerve injury at the level of the needle.

Rarely, blood vessels close to the nerve root can be damaged by the needle. This can cause a collection of blood which can create pressure on the nerve (1 in 50,000). If this occurs it may need active treatment to correct.

Other problems (i.e allergy) are considered to be very rare.

After the examination

You may experience some soreness or bruising at the needle site and rarely, minor muscle spasm. You may also experience some temporary numbness at the injection site and in your affected limb. Occasionally referred pain can increase in the days after procedure.

Once you are feeling comfortable you may leave. We recommend you have someone to drive you home after the procedure. Please consider this when making your appointment. We request you do not perform any lifting or physical activities that may aggravate your condition for at least 12 hours after the procedure.

Effects from the treatment

The local anaesthetic may provide temporary pain relief for up to four hours. Paracetamol may be taken if you experience discomfort. The steroid can take up to a week to reach maximum effect. Relief from symptoms does vary between patients, both in time and scale.

Some people do not receive pain relief from the procedure if the nerve root is not the cause for their pain. This is generally not a failure of the procedure. This information is useful for your doctor and indicates other causes of pain may need to be considered.