Image Guided Cervical Nerve Root Sleeve Corticosteroid Injection

Authors: Prof Mark Khangure*
                            Dr Jason Wenderoth *

What is a a cervical nerve root sleeve injection?

The spine is made up of bones called vertebrae. Between each vertebra is a ‘disc’ that allows the spine to be flexible. The nerves that provide sensation and power to the upper limbs are called
cervical nerves. They exit the spine through openings between two adjacent vertebrae called the intervertebral foramina. There are eight cervical nerves on each side of the neck. The nerve roots are surrounded by fat.

A cervical nerve root sleeve injection is where anti-inflammatory medication called corticosteroid (or ‘steroid’) and a local anaesthetic are injected into the fat surrounding the nerve root. Corticosteroid medication decreases inflammation in the nerve root and will often reduce pain caused by nerve root inflammation, irritation caused by arthritis or conditions such as a prolapsed disc (where the disc bulges) in your neck.

Why would my doctor refer me to have this procedure?

Irritation, compression and inflammation of the nerve caused by a prolapsed disc or a bony spur from arthritis in the neck can cause arm and neck pain. This is more common in older people, but can occur in anyone who has arthritis in the neck. It can also occur after a neck injury.

Your doctor may refer you for relief of this pain in the following situations:

• To control pain while you are waiting for surgery.
• To control pain while allowing disc material to shrink and inflammation to go away, which often happens naturally without surgery.
• When you have arthritis or disc problems at several levels in your neck. Injection of nerve roots at one or two levels can help to determine which level is the cause of your pain. This may be helpful in planning surgical treatment of the disc.

How do I prepare for a cervical nerve root sleeve injection?

You may have a light meal up to 2–3 hours before the procedure.

You should wear comfortable clothes that are easy to remove and leave jewellery at home, especially necklaces. Please note that some of the disinfectant agents used during these procedures may stain light-coloured clothing.

When you make your appointment for the cervical nerve root sleeve injection, you need to let the radiology clinic or department know if you are taking any blood thinning medication, such as warfarin, clopidogrel, dabigatran, prasugrel, dipyridamole or asasantin (for more information about these medications, go to NPS: www.nps.org.au/medicines).

Blood thinning medications may need to be stopped for a period of days, or your normal dose reduced, before this procedure is carried out. It is very important that you do not stop any of these medications or change the dose without consulting both the radiology clinic or department and your own doctor. They will give you specific instructions about when to stop and restart the medication. These drugs are usually prescribed to prevent stroke or heart attack, so it is very important that you do not stop taking them without being instructed to do so by your doctor or the radiology practice, or both. Aspirin is usually not stopped.

A blood test may be required to check your blood clotting on the day of the procedure.

Continue with pain medication and other medications as usual.

You may be monitored for 2–3 hours after the procedure in the hospital, so please allow for this. You will need to arrange for someone to take you home, as it is not advisable to drive immediately after the procedure, because you may have numbness, weakness or other temporary side-effects after the procedure.

What happens during a cervical nerve root sleeve injection?

You will be asked to change into a hospital gown in a changing room, and someone will look after your clothes and valuables during the procedure.

You will be taken into the room where the procedure is carried out, either a computed tomography (CT) scanner room or an angiography suite. You will be asked to lie on your back on the table, which is covered with a thin foam mattress. The table has an X-ray machine under it and a screen over the top of it. There is a television screen where images or pictures of the body can be viewed directly by the radiologist (specialist doctor) carrying out the procedure. With a CT guided procedure, the table moves into the CT tunnel and cross-sectional images of the spine are taken.

The nerve root to be injected is located and an ink mark is placed on the skin to show where the needle will be inserted.

The skin is cleaned with an antiseptic, which is usually very cold. The area is then covered with a sterile drape. The skin and deeper tissues are then injected with local anaesthetic. This produces a pin prick and a stinging sensation that is uncomfortable for a few seconds. You will be awake and only the area where the nerve root sleeve injection is being carried out will be numb.

When the skin and muscles are numb, a thin spinal needle is then guided into the intervertebral foramen where the nerve is located. The CT scanner or an X-ray machine will be used to guide this and may be quite close to your face while the radiologist is locating the place for the injection and placing the needle into this spot.

When the needle is in the correct location, contrast medium (or dye) is injected to ensure that the needle is in the correct space and not in a blood vessel. The contrast contains iodine that makes it visible using an X-ray machine or CT scanner (See Iodine-containing contrast medium (ICCM)).

A combination of a long-acting local anaesthetic and a water-soluble corticosteroid is then injected into the tissues surrounding the nerve root. The placement of the needle and injection of contrast into the foramen may produce some discomfort if the foramen is very tight from disc problems or if there is a bony spur compressing the nerve root. The long-acting local anaesthetic very rapidly numbs the nerve. The area of the limb supplied by the nerve being treated goes numb and the arm, shoulder or hand may feel ‘dead’ for a while. This can be worrying when it happens, but you should be aware that the feeling and movement will recover soon.

Are there any after effects of a cervical nerve root sleeve injection?

• The upper limb may be numb and ‘useless’ until the anaesthetic wears off, which may be as long as 2 hours after the injection. The anaesthetic may produce some numbness in your other arm, but this will go away after a short time.
• Irritation of the nerve by the procedure may produce further upper limb pain until the corticosteroid starts working, usually 24-48 hours. Pain medication and rest for 1-2 days is usually recommended during this initial period after the local anaesthetic wears off and before the anti-inflammation effect of the corticosteroid begins.
• Hot flushing of the face and/or whole body.

If any of the following develop seek immediate medical attention:

• High fever or night sweats or shivers.
• Severe headache, nausea and vomiting, and sensitivity to bright lights (which can be indications of meningitis).
• Increasing numbness or weakness in the limbs more than 8 hours after the procedure.

How long does a cervical nerve root sleeve injection take?

The actual procedure itself takes approximately 15 minutes. You may be monitored for 2–3 hours after the procedure, so please allow for this. Monitoring occurs after the procedure to make sure any numbness, weakness or other temporary side-effects of the procedure have worn off before you go home. You will also have your blood pressure and breathing monitored after the procedure.

What are the risks of a cervical nerve root sleeve injection?

There are minor, moderately severe, and serious (but rare) risks associated with this procedure. In one group of over 4612 patients undergoing this procedure¹, there were no major complications and approximately 30 minor complications that resolved without the need for any further intervention.

The minor complications that can occur are:

• Fainting when you are helped off the table after the procedure.
• Pins and needles in your hands and feet from hyperventilation (this is rapid breathing that sometimes happens when you are nervous or anxious).
• Local skin bruising or redness where the injection enters the skin.

The moderately severe complications are very uncommon, but if you have them you should tell the staff at the hospital clinic or department where the procedure is carried out. Many of these complications happen at the time of or very soon after the procedure while you are still at the hospital, and you should tell the staff who are looking after you if you notice any of these.

• Temporary difficulty breathing and moving your legs, arms or both. This is caused by the local anaesthetic passing along the nerve root into the space around the spinal cord (called the epidural space). This problem can be frightening when it happens, but is generally short lived and goes away as the local anaesthetic wears off. If it happens, you will most likely be admitted to hospital for observation, and in rare cases you may need intensive care if your breathing is severely compromised.
• Bleeding. Bleeding is more common if you have very high blood pressure or are taking blood-thinning medications. It can cause compression of the nerve that is being injected. This may result in persistent weakness or pain in your arm for longer than normal. Bleeding can also occur from the site where the needle enters the skin if you are taking these medications. This is why you are asked to stop taking them, or to reduce the amount you take, a few days before the procedure.
• Infection where the injection enters the skin. Increasing pain in the neck and a fever may indicate a local infection in the skin or muscles that were injected. Severe headache, neck stiffness and pain when you look at bright lights that start in the few days after the procedure may indicate a more serious infection (either meningitis or an epidural infection). You should see your doctor immediately if you develop these problems, as they need to be treated in hospital with antibiotics.
• Leakage of cerebrospinal fluid causing a headache. This problem is caused by fluid around the nerve root, which is in contact with the fluid around the spinal cord, leaking as a result of the injection. Fluid can continue to leak slowly after the procedure and this is commonly experienced as a fairly severe headache. This is usually worse on standing, and helped by lying flat. The headache generally goes away in a day or so, because the leak will seal off by itself. Lying flat in bed, drinking lots of fluids and taking simple analgesia, such as paracetamol, is all that is required.
• Local anaesthetic injected deep into the skin may block the nerves that surround the carotid artery, causing temporary redness of the eye, an unequal pupil and blurred vision, and occasionally hoarseness of voice. These clear up in 30 minutes or so as the local anaesthetic wears off.
• Contrast reaction. Any test or procedure that involves injection of contrast medium (often called ‘contrast’ or ‘dye’, even though it is clear and colourless) can trigger an allergic type reaction (see Iodinated Contrast Media). If you know you have had a reaction to contrast or X-ray dye in the past, it is important to tell the hospital when you make your appointment. You will most likely need premedication (tablets taken for a couple of days before the procedure) if you had a genuine previous allergic reaction. You may be advised not to have the procedure at all. A radiologist will help to make this decision with you and your doctor.
• Difficulty swallowing. This may occur if the needle tip is in the vertebral artery and the local anaesthetic is injected into the artery, resulting in a temporary lack of function of the nerves that control swallowing. This will go away as the local anaesthetic wears off in the hour or so after the procedure. Excessive bleeding at the injection site may rarely cause direct compression of the oesophagus (the tube between your mouth and stomach), making it hard to swallow.

Serious and permanent, but very rare, complications of this procedure include stroke, spinal cord injury leading to partial paralysis and nerve root injury, these lead to permanent problems with movement and feeling in your arms.

It is hard to be certain about exactly how rare the risk is, because what we know about these complications comes from multiple small studies rather than one large study. Fewer than 1 in 1000 people could expect to experience any of these serious complications if the procedure is carried out by an experienced radiologist. It is thought that these problems generally occur because the corticosteroid medication enters a blood vessel supplying the spinal cord or brain. Having this procedure carried out using a CT scanner or high resolution fluoroscopy equipment, rather than a standard fluoroscopy to guide the placement of the needle and avoid the blood vessels, is thought to make this procedure safer and to reduce the risk of this complication. The use of water-soluble corticosteroids further reduces the risk of complication. These complications, if they occur, happen within minutes of the procedure, so you will still be in the hospital or practice should any of these rare problems occur.

Direct injection of the nerve root may damage the nerve permanently.

Accurate needle placement, high-resolution image guidance and skilled specialist doctors are essential to avoid the major complications that arise as a result of poor quality imaging. It is essential that a water-soluble corticosteroid is used.

What are the benefits of a cervical nerve root sleeve injection?

The benefits of this procedure are relief of arm and neck pain, and avoidance of or delay in surgery. Pain relief may last days to months. The procedure can be repeated every 2–4 months, as long as no weakness develops in your arms as a result of the injection.

Who does the cervical nerve root sleeve injection?

Cervical nerve root sleeve injections are usually carried out by radiologists (specialist doctors) and sometimes by pain-management specialists. The doctor carrying out the procedure needs to be appropriately trained in carrying out this procedure, and recognising and managing any minor and severe complications that may occur.

Where is a cervical nerve root sleeve injection done?

The procedure must be carried out in or close to a hospital setting with access to anaesthesiology and an intensive care unit (ICU). It is best carried out with either X-ray guidance from CT or high-resolution fluoroscopy equipment that is generally found in an angiography suite of a hospital. Standard fluoroscopy equipment may not be sufficient to allow this procedure to be carried out safely.

When can I expect the results of my cervical nerve root sleeve injection?

The time it takes your doctor to receive a written report on the test or procedure will vary depending on:

• the urgency with which the results are required by your doctor;
• the complexity of the test or procedure;
• whether more information is needed from your doctor before the test or procedure can be interpreted by the radiologist;
• whether you have had previous X-rays or other medical imaging that need to be compared with this test or procedure (this is commonly the case if you have a disease or condition that is being assessed as to its progress);
• how the report is sent to your doctor (i.e. phone, email, fax or mail).

Please feel free to ask the private practice, clinic, or hospital when the written report will be provided to your doctor.

It is important that you discuss the results with your doctor, either in person or on the telephone, so that they can explain what the results mean for you.

Further information about cervical nerve root sleeve injection:

This procedure is safe when carried out by an experienced doctor using high-resolution equipment. The rarer complications are potentially very serious. Because most people who choose to have this procedure have pain, but not a life threatening condition, these very small but serious risks need to be considered, as do the risks of alternative treatments, such as surgery.

Does this procedure need to be done under general anaesthesia?

No. The most uncomfortable part of the procedure is the initial injection of local anaesthetic. After this, the rest of the procedure is usually not especially painful.

References:

1. Schellhas, KP et al. Selective cervical nerve root blockade: experience with a safe and reliable technique using an anterolateral approach for needle placement. AJNR Am J Neuroradiol, 2007. 28(10): p. 1909–14.

*The author has no conflict of interest with this topic.

Page last modified on 26/7/2017.