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CT-Guided Neck Nerve Root Injection for Arm Pain (Cervical Transforaminal Epidural Steroid Injection)

CT-Guided Neck Nerve Root Injection for Arm Pain (Cervical Transforaminal Epidural Steroid Injection)

By Mr Ahmed-Ramadan Sadek, Neurosurgeon · 12 min read

🎧 Listen to this guideAudio version coming soon. Narrated in Mr Sadek’s voice using AI voice technology, from a script he has reviewed.

On this page

Key points

  • Arm pain from a trapped nerve in the neck (cervical radiculopathy) usually improves a great deal over weeks to months. Most people never need an injection or an operation.[1][2][3]
  • A CT scanner guides a fine needle to the opening where the nerve leaves the spine, and local anaesthetic and a steroid are placed next to the nerve.[4][5]
  • In studies without a comparison group, about 35 to 55 in 100 people had at least half of their pain relieved weeks to months later.[6][7] Randomised trials are few and small, and the evidence is of low to very low certainty.[8][9][7]
  • Short-lived side effects, such as a pain flare, a numb arm for some hours or a rise in blood sugar, are fairly common.[10][11][4][12]
  • Very rarely, neck injections have caused stroke, spinal cord injury or death. The true risk is unknown but very small.[13][14][15][4]
  • NICE has no guideline on neck injections; NG59 covers the lower back only.[16]

📄 Download a one-page summary to print or share (PDF)

After a neck injection, call 999 or go to A&E if you have:

  • Signs of a stroke (FAST): one side of the face drooping, being unable to lift both arms and keep them up, or slurred or confused speech. Time to call 999.[17]
  • Weakness or numbness down one side of the body, or spreading beyond the injected arm, for example into the face, the other arm or the legs.[17][18]
  • Blurred vision or loss of sight, feeling dizzy or falling over, or difficulty speaking or thinking of words.[17][18]
  • A headache that starts suddenly and is extremely painful, or a headache with a seizure (fit).[19][18]
  • A headache with a very high temperature, a stiff neck, or bright lights bothering you.[19]

Some numbness or weakness in the injected arm for a few hours is expected.[4][5] The symptoms above are different. Call 999 even if they stop, and do not drive yourself to A&E.[17]

Arm pain from a trapped nerve in the neck

Nerves leave the neck through small openings between the bones called foramina. A disc bulge or bony wear can press on one of these nerves and cause pain, pins and needles, numbness or weakness in the arm. Our cervical radiculopathy guide explains the condition in more detail.

The outlook is usually good. In a population study from Rochester, Minnesota, 90 in 100 people had no or only mild symptoms after a median of almost 5 years, although 26 in 100 had an operation and about 32 in 100 had a further episode.[2] A systematic review found most improvement comes within 4 to 6 months, with about 83 in 100 fully recovered by 2 to 3 years.[3] NICE’s summary for GPs estimates that 8 to 33 in 100 people with nerve root pain need surgery.[1]

For the first 4 to 6 weeks, that summary advises reassurance, painkillers and, if needed, physiotherapy. If symptoms last longer or there is weakness, it advises referral for an MRI scan and to consider injections or surgery. It also lists clumsy or weak hands, difficulty walking and new bladder or bowel problems as reasons for referral.[1] These can mean pressure on the spinal cord: see our cervical myelopathy guide.

What is a CT-guided nerve root injection?

It is a type of epidural injection given through the foramen, so doctors call it a transforaminal injection. A local anaesthetic numbs the nerve for some hours and a steroid reduces inflammation around it.[4][5] Many teams first inject a little contrast dye, which shows on the scan, to check the needle is in the right place,[5] although one London unit does not routinely use dye.[4]

If numbing the nerve does not ease your usual pain, that nerve may not be the source, which helps if surgery is being planned.[4] Our nerve root injections guide covers the lower back.

Why use CT guidance?

Most neck nerve root injections are guided by live X-ray (fluoroscopy). CT instead gives cross-section pictures showing the bone, nerve opening, nearby blood vessels and needle tip in detail.[20][4] It does not remove every risk. In two US studies of CT-guided neck injections, contrast entered a blood vessel, mostly a vein, in 24 to 26 in 100 procedures.[21][22] Keeping the needle tip just outside the nerve opening lowered this to about 10 in 100.[21] This is why safety guidance stresses imaging checks before the steroid goes in.[23][24]

CT-guided transforaminalX-ray guided transforaminalInterlaminar (between the bones at the back)
How the needle is guidedCross-section CT pictures show the needle tip, nerve, bone and vessels[20][4]Live X-ray pictures, sometimes with an extra vessel check called digital subtraction[24][25]Into the epidural space at the back of the spine rather than at one nerve opening
RadiationHigher: the CT steps added about 19 times the dose of plain X-ray screening in one study, though still small[25]Lowest of the guided transforaminal methods measured[25]Not compared in the sources used here
Particular risksMedicine entering a vessel in 24 to 26 in 100 procedures, mostly veins; rare stroke or spinal cord injury[21][22][26]Rare stroke or spinal cord injury reported[13][14]Accidental puncture of the fluid sac (dural puncture) more common: 2 in 1,000 versus 4 in 10,000 for transforaminal, in a study mostly of lower back injections[11]

How well does it work?

Two systematic reviews of X-ray guided neck nerve root injections found that about half of people had at least half of their arm pain relieved. One found this for at least 4 weeks.[14] The other pooled 48 in 100 at 1 month and 55 in 100 at 3 months.[7] Both rated the evidence as very low quality, mainly because almost no studies had a proper comparison group.[14][7]

Results with CT guidance are similar or a little lower. In a US study of 247 people, about 35 in 100 had more than half of their pain relieved at 2 months.[6] In a UK study, 113 people had a CT-guided injection and 80 were followed for a year: 45 in 100 had a meaningful fall in neck pain and 56 in 100 a meaningful improvement in disability.[27]

Randomised trials are few and small. A Swedish trial of 40 people compared local anaesthetic with steroid against local anaesthetic with salt water and found no difference at 3 weeks.[8] A US trial of 169 people compared injections, medicines with physiotherapy, or both. There was no clear difference in arm pain at 1 month. At 3 months, a good outcome was reported by 37 in 100 after injections, 27 in 100 after medicines and physiotherapy, and 57 in 100 after both.[9] A 2022 review found no clear advantage of the transforaminal route over injecting between the bones at the back (interlaminar).[28]

Put simply, the injection may give useful relief for some people while the nerve settles, but because most people improve anyway, we cannot be sure how much is due to the injection. One review suggests it may reduce the need for surgery, again on very low quality evidence.[14]

What NICE and safety bodies say

NICE guideline NG59 covers low back pain and sciatica only; for acute and severe sciatica it suggests considering an epidural injection of local anaesthetic and steroid.[16] In October 2026 we found no NICE guideline or interventional procedures guidance on neck injections. NICE’s summary for GPs, which is not formal guidance, advises referral to consider injections or surgery if symptoms last 4 to 6 weeks or more, or there are signs such as weakness.[1]

In 2014 the US Food and Drug Administration (FDA) required a warning on injectable steroid labels: epidural steroid injections can rarely cause loss of vision, stroke, paralysis and death, and their safety and effectiveness for this use have not been established.[18] In 2015, a working group of 13 specialist societies, convened through an FDA safety initiative, published 17 safety recommendations covering image guidance, anatomy and the use of a steroid that does not contain particles.[23] Reviews also describe a test dose of local anaesthetic and little or no sedation.[24]

Who may be offered it

It is usually offered when arm pain from a trapped nerve, seen on MRI, has not settled with simpler treatment, or to confirm which nerve is causing the pain. You and your doctor decide together.[1][4][5]

Tell the team before the day if you:

  • Have an infection anywhere, including on the skin of your neck. The injection may be delayed.[5]
  • Take blood-thinning medicine. Extra preparation may be needed; do not stop it unless told to.[5][4]
  • Are or might be pregnant. One NHS trust does not perform it in pregnancy;[5] another may rebook or, if urgent, take extra precautions.[4]
  • Have any allergies, including to local anaesthetic or contrast dye.[5][4]
  • Have diabetes. The steroid can raise blood sugar for a day or two, whatever your usual control,[12] so you may need to check it more often and adjust your diabetes medicine with advice.[5]
  • Plan to fly or travel abroad within two weeks.[5]

On the day

  1. The doctor explains the risks, benefits and alternatives and asks for your written consent.[4][5]
  2. You lie on your back on the CT table. The skin is cleaned and numbed with local anaesthetic, which stings briefly.[4][5]
  3. Several short scans check the needle tip as it moves forward. You may feel pressure, tingling or your usual arm pain.[4][5]
  4. Contrast dye, a test dose of local anaesthetic, or both, may be given first to check the medicine is not entering a blood vessel.[24][5]
  5. The procedure takes about 20 minutes. You are watched for up to an hour afterwards, so allow at least 2 hours.[4][5]
  6. Someone must take you home. Do not drive, as your insurance may not cover you.[4][5]

After the injection

  • Your arm may feel numb, heavy, clumsy or weak. This usually wears off within hours and is unlikely to last beyond about 18 hours.[4][5]
  • The local anaesthetic may ease pain for 12 to 24 hours. The steroid usually starts to work after 1 to 3 days, but the benefit is often delayed for up to 7 to 10 days.[4]
  • Your usual pain may flare for a few days. Keep taking your normal painkillers and medicines.[5][4]
  • The steroid can cause flushing, poor sleep, mood or period changes and a rise in blood sugar, all temporary.[5][11] In 30 people with diabetes, blood sugar was back to its usual range within about 2 days.[12]
  • Do not drive for 24 hours and until you feel fit. Ideally have someone with you for 24 hours, and avoid alcohol until you feel fit.[5]
  • Report any new blurred or distorted vision to your doctor.[5]

How many injections?

There is no agreed number. One London unit repeats it at the same level up to three times if relief is partial or short-lived,[4] and a US trial allowed up to three injections in six months.[9] Steroid side effects are more likely with repeated injections.[5]

Risks

Most figures come from mixed neck and lower back studies, or small neck studies, so treat them as a guide.

Common and usually minor

  • Flare of pain: about 2 in 100 in a large mixed study[11] to 18 in 100 (more arm pain straight after a neck injection) in a small study.[10]
  • Temporary numbness or weakness of the arm: expected for some hours from the local anaesthetic.[4][5]
  • Flushing, poor sleep or headache: about 3 in 100 (a steroid reaction, in a large mixed study)[11] to 5 in 100 (headache after neck injections, in a small study).[10]
  • Raised blood sugar for about 2 days in people with diabetes.[12]

Less common

  • Feeling faint or fainting: about 1 in 100 fainted (a vasovagal reaction) in a large mixed study,[11] while 14 in 100 felt light-headed straight after neck injections in a small study.[10]
  • Dural puncture: the needle enters the fluid sac around the nerves in about 4 in 10,000 transforaminal injections.[11] This can cause a headache that needs treatment. Lying flat may help; contact your GP if it lasts more than 24 hours.[5]
  • Infection or bleeding: rare. Large series of 16,638 and 26,061 procedures recorded no serious bleeding, and the first found no infection on follow-up.[11][29]
  • Any minor complication of a neck nerve block: about 17 in 1,000 in a series of 1,036 injections.[15]

Rare but serious

The most feared risk is damage to the brain stem or spinal cord, thought to happen mainly when steroid containing particles enters a small artery and blocks it.[13][24] A survey of US pain doctors collected 78 complications, including 16 strokes at the back of the brain, 12 spinal cord infarcts and 13 deaths.[13] A 2014 review found 21 published reports of serious complications, including 13 deaths.[14] The needle itself has also injured the spinal cord during a CT-guided injection, leaving lasting weakness.[26]

Nobody knows exactly how often this happens, because case reports do not tell us how many injections were given in total.[24] A series of 1,036 neck nerve blocks[15] and a mixed series of 16,638 epidural injections[11] recorded no catastrophic events. One NHS unit estimates the risk as much rarer than 1 in 1,000;[4] another says it is too rare to give a reliable figure.[5] A steroid without particles, a test dose and careful imaging checks are meant to lower the risk.[23][24]

Radiation

CT uses more radiation than X-ray screening. In one study the CT steps of a neck injection added about 0.05 millisieverts, roughly 19 times the X-ray method but less than a transatlantic flight (about 0.08).[25][30] Most of the dose comes from the planning scan, and one hospital cut it by about four-fifths by changing that step.[31] One NHS unit compares a whole procedure to about four months of natural background radiation (UK average about 2.6 millisieverts a year).[4][30]

Other options

  • Watchful waiting: most nerve root pain improves with time.[1][3]
  • Physiotherapy and staying active, which may include exercises and hands-on treatment.[1]
  • Painkillers: your GP or pharmacist can advise which suit you.[1]
  • Surgery, usually considered when arm pain is disabling despite 6 to 12 weeks of other treatment, or weakness is getting worse, and MRI shows nerve compression.[1] Options include neck surgery from the front (ACDF), endoscopic cervical foraminotomy and neck surgery from the back.

Ask for an urgent GP appointment or get help from NHS 111 if the skin around the injection becomes painful, hot and swollen.[32][5] Call 999 or go to A&E if this comes with a very high temperature, feeling hot, cold or shivery, a fast heartbeat or breathing, or feeling dizzy or confused.[32] Contact your GP or the team if a headache lasts more than 24 hours.[5] Contact your treating team the same day if arm numbness or weakness has not worn off by the next day.[4]

Questions you may want to ask

  • Is the injection to treat my pain, to find which nerve is the cause, or both?
  • Who will do it, and will you use CT or X-ray guidance, contrast dye and a test dose?
  • Will the steroid be one that does not contain particles?
  • What should I do about my blood-thinning or diabetes medicine?
  • What are my chances of improving without the injection?
  • If it helps and the pain returns, would you repeat it, and how often?
  • If it does not help, what next?
  • Who do I contact if I have problems afterwards?

Frequently asked questions

Does a nerve root injection in the neck hurt?

Most people find it uncomfortable rather than very painful. The local anaesthetic used to numb the skin stings briefly.[4][5] As the needle is moved into place you may feel pressure, tightness or a short burst of your usual arm pain, and you should tell the doctor if it becomes uncomfortable.[4][5] Afterwards the area may be tender or bruised for a few days.[5] Whether sedation is offered varies between hospitals, so ask your team.

How long does a neck nerve root injection take to work?

It can take a few days to over a week. The local anaesthetic may ease the pain for 12 to 24 hours. The steroid usually starts to work after 1 to 3 days, and one NHS neuroradiology unit says it is quite common for the benefit to be delayed for up to 7 to 10 days.[4] Your pain may also flare for a few days before it improves.[5]

How long does a cervical nerve root injection last?

There is no single answer, and some people get no benefit. In studies without a comparison group, about 48 in 100 people had at least half of their pain relieved at 1 month and 55 in 100 at 3 months,[7] while a CT-guided study found about 35 in 100 at 2 months.[6] A UK study found that 45 in 100 people still had a meaningful improvement in neck pain a year later.[27] The evidence is of very low quality, so these figures are only a rough guide.[7]

Why have the injection under CT rather than X-ray?

CT shows cross-section pictures of the bone, the nerve opening, nearby blood vessels and the needle tip in detail, while live X-ray (fluoroscopy) is the more common method.[20][4] CT does not remove the risk of medicine entering a blood vessel: this happened in 24 to 26 in 100 CT-guided neck injections in two studies, mostly into veins.[21][22] CT also uses more radiation, although the extra dose measured in one study was less than a transatlantic flight.[25][30]

Can a neck injection help me avoid surgery?

Possibly, but nobody can promise it. A systematic review suggested these injections may reduce the need for surgery, but rated the evidence as very low quality.[14] Most people with a trapped nerve in the neck improve with time anyway: in one population study, 90 in 100 had no or only mild symptoms after about 5 years, although 26 in 100 had an operation.[2] Surgery is usually considered when pain stays disabling after 6 to 12 weeks, or weakness is getting worse, and the MRI shows the nerve is squashed.[1]

Can a cervical epidural injection cause a stroke or paralysis?

Very rarely, yes. In 2014 the US Food and Drug Administration warned that epidural steroid injections can rarely cause loss of vision, stroke, paralysis and death.[18] Reports include strokes at the back of the brain and spinal cord damage after neck injections.[13][14] The true risk is unknown: a series of 1,036 neck nerve blocks found no catastrophic events,[15] one NHS unit estimates the risk as much rarer than 1 in 1,000,[4] and another says it is too rare to give a reliable figure.[5] Safety steps include imaging checks, a test dose and a steroid that does not contain particles.[23][24]

Will a steroid injection in my neck affect my diabetes?

It may raise your blood sugar for a short time. In a study of 30 people with diabetes, blood sugar rose noticeably after an epidural steroid injection but was back within its usual range within about 2 days, and how well controlled the diabetes was beforehand did not predict the rise.[12] An NHS leaflet advises that you may need to check your blood sugar more often and adjust your diabetes medicine.[5] Tell the team before the day, and ask your GP, diabetes nurse or pharmacist what to do if readings stay high.

When should I get urgent help after a neck injection?

Call 999 if you have signs of a stroke: a drooping face, being unable to lift both arms, slurred speech, blurred vision or loss of sight, or weakness or numbness down one side of the body.[17] Weakness or numbness spreading beyond the injected arm, a sudden extremely painful headache, or a headache with a high temperature and stiff neck also need 999 or A&E.[18][19] Some numbness in the injected arm for a few hours is expected.[4] Ask for an urgent GP appointment or call NHS 111 if the skin around the injection becomes painful, hot and swollen.[32]

Further reading

References

  1. National Institute for Health and Care Excellence. Clinical Knowledge Summaries: Neck pain, cervical radiculopathy (management). Last revised November 2023. Link
  2. Radhakrishnan K, Litchy WJ, O’Fallon WM, Kurland LT. Epidemiology of cervical radiculopathy. A population-based study from Rochester, Minnesota, 1976 through 1990. Brain. 1994;117(Pt 2):325-335. Link
  3. Wong JJ, Côté P, Quesnele JJ, Stern PJ, Mior SA. The course and prognostic factors of symptomatic cervical disc herniation with radiculopathy: a systematic review of the literature. Spine J. 2014;14(8):1781-1789. Link
  4. University College London Hospitals NHS Foundation Trust, Lysholm Department of Neuroradiology. CT-guided steroid injections (patient information). Page last updated 8 July 2026. Link
  5. Mersey and West Lancashire Teaching Hospitals NHS Trust. CT guided nerve root injections: patient leaflet (MWL2531, version 1). Review date March 2028. Link
  6. Wald JT, Maus TP, Geske JR, et al. Safety and efficacy of CT-guided transforaminal cervical epidural steroid injections using a posterior approach. AJNR Am J Neuroradiol. 2012;33(3):415-419. Link
  7. Conger A, Cushman DM, Speckman RA, et al. The effectiveness of fluoroscopically guided cervical transforaminal epidural steroid injection for the treatment of radicular pain; a systematic review and meta-analysis. Pain Med. 2020;21(1):41-54. Link
  8. Anderberg L, Annertz M, Persson L, Brandt L, Säveland H. Transforaminal steroid injections for the treatment of cervical radiculopathy: a prospective and randomised study. Eur Spine J. 2007;16(3):321-328. Link
  9. Cohen SP, Hayek S, Semenov Y, et al. Epidural steroid injections, conservative treatment, or combination treatment for cervical radicular pain: a multicenter, randomized, comparative-effectiveness study. Anesthesiology. 2014;121(5):1045-1055. Link
  10. Huston CW, Slipman CW, Garvin C. Complications and side effects of cervical and lumbosacral selective nerve root injections. Arch Phys Med Rehabil. 2005;86(2):277-283. Link
  11. El-Yahchouchi CA, Plastaras CT, Maus TP, et al. Adverse event rates associated with transforaminal and interlaminar epidural steroid injections: a multi-institutional study. Pain Med. 2016;17(2):239-249. Link
  12. Even JL, Crosby CG, Song Y, McGirt MJ, Devin CJ. Effects of epidural steroid injections on blood glucose levels in patients with diabetes mellitus. Spine (Phila Pa 1976). 2012;37(1):E46-E50. Link
  13. Scanlon GC, Moeller-Bertram T, Romanowsky SM, Wallace MS. Cervical transforaminal epidural steroid injections: more dangerous than we think? Spine (Phila Pa 1976). 2007;32(11):1249-1256. Link
  14. Engel A, King W, MacVicar J; Standards Division of the International Spine Intervention Society. The effectiveness and risks of fluoroscopically guided cervical transforaminal injections of steroids: a systematic review with comprehensive analysis of the published data. Pain Med. 2014;15(3):386-402. Link
  15. Ma DJ, Gilula LA, Riew KD. Complications of fluoroscopically guided extraforaminal cervical nerve blocks. An analysis of 1036 injections. J Bone Joint Surg Am. 2005;87(5):1025-1030. Link
  16. National Institute for Health and Care Excellence. Low back pain and sciatica in over 16s: assessment and management (NG59). Published 30 November 2016; last updated 29 July 2026. Link
  17. NHS. Symptoms of a stroke. NHS website; page last reviewed 12 September 2024. Link
  18. US Food and Drug Administration. FDA Drug Safety Communication: FDA requires label changes to warn of rare but serious neurologic problems after epidural corticosteroid injections for pain. 23 April 2014 (archived copy). Link
  19. NHS. Headaches. NHS website; page last reviewed 17 April 2024. Link
  20. Wald JT, Maus TP, Diehn FE, et al. CT-guided cervical transforaminal epidural steroid injections: technical insights. J Neuroradiol. 2014;41(3):211-215. Link
  21. Lagemann GM, Yannes MP, Ghodadra A, Rothfus WE, Agarwal V. CT-fluoroscopic cervical transforaminal epidural steroid injections: extraforaminal needle tip position decreases risk of intravascular injection. AJNR Am J Neuroradiol. 2016;37(4):766-772. Link
  22. Kranz PG, Amrhein TJ, Gray L. Incidence of inadvertent intravascular injection during CT fluoroscopy-guided epidural steroid injections. AJNR Am J Neuroradiol. 2015;36(5):1000-1007. Link
  23. Rathmell JP, Benzon HT, Dreyfuss P, et al. Safeguards to prevent neurologic complications after epidural steroid injections: consensus opinions from a multidisciplinary working group and national organizations. Anesthesiology. 2015;122(5):974-984. Link
  24. Malhotra G, Abbasi A, Rhee M. Complications of transforaminal cervical epidural steroid injections. Spine (Phila Pa 1976). 2009;34(7):731-739. Link
  25. Maus T, Schueler BA, Leng S, et al. Radiation dose incurred in the exclusion of vascular filling in transforaminal epidural steroid injections: fluoroscopy, digital subtraction angiography, and CT/fluoroscopy. Pain Med. 2014;15(8):1328-1333. Link
  26. Chang MC. Spinal cord injury by direct damage during CT-guided C7 transforaminal epidural steroid injection. Am J Phys Med Rehabil. 2018;97(7):e62-e64. Link
  27. Aldin Z, Diss JK, Mahmood H, et al. Long-term effectiveness of transforaminal anterolateral approach CT-guided cervical epidural steroid injections for cervical radiculopathy treatment. Clin Radiol. 2024;79(5):e775-e783. Link
  28. Lee JH, Lee Y, Park HS, Lee JH. Comparison of clinical efficacy of transforaminal and interlaminar epidural steroid injection in radicular pain due to cervical diseases: a systematic review and meta-analysis. Pain Physician. 2022;25(9):E1351-E1366. Link
  29. Carr CM, Plastaras CT, Pingree MJ, et al. Immediate adverse events in interventional pain procedures: a multi-institutional study. Pain Med. 2016;17(12):2155-2161. Link
  30. UK Health Security Agency. Ionising radiation: dose comparisons. GOV.UK; updated 28 September 2026. Link
  31. Paik NC. Radiation dose reduction in CT fluoroscopy-guided cervical transforaminal epidural steroid injection by modifying scout and planning steps. Cardiovasc Intervent Radiol. 2016;39(4):591-599. Link
  32. NHS. Cellulitis. NHS website; page last reviewed 18 April 2024. Link

This article is general information and is not a substitute for advice about your own situation. Please speak to your GP or specialist before making any change to your treatment.

Last checked: October 2026