Cauda equina syndrome early recognition study

Plain English summary of protocol

Background and study aims
Cauda equina syndrome (CES) describes the symptoms that occur when multiple lumbar and sacral nerve roots become compressed within the vertebral canal (at the bottom of the spinal cord). Its symptoms include low back pain, perineal sensory change, and bladder or bowel dysfunction. CES is a spinal emergency and the most common cause – a large central lumbar disc herniation – requires surgical decompression in almost all cases. CES commonly causes long-term disability, including permanent paralysis, impaired bladder and/or bowel control, and sexual dysfunction.
Nerve root viability declines after around 6 hours and prolonged compression rapidly leads to degeneration in motor and sensory nerve roots. As prognosis is likely worsened by delay between symptom onset and decompression, the consensus is that surgical intervention should be undertaken as soon as possible. The Society of British Neurological Surgeons (SBNS) and the British Association of Spine Surgeons (BASS) have published guidance that strongly emphasises the need for early diagnosis and decompression.

Unfortunately, making the diagnosis can be challenging and only around 0.1% of patients attending an Emergency Department with low back pain have CES. Nevertheless, there is good evidence that NHS services often fail to provide adequate care for patients with suspected CES. Although national guidelines recommend a very low threshold for MRI, many clinicians still rely on clinical judgement when assessing these patients and most hospitals cannot access MRI scanning outside normal working hours. As a consequence, patients with CES continue to experience unacceptable delays to surgery and failure to diagnose CES promptly costs the NHS around £33 million per year in litigation costs alone. It is for these reasons that the Royal College of Emergency Medicine (RCEM) highlighted the importance of “further research into the diagnosis of CES, both to define those clinical features which most accurately predict CES and the need for MRI”. There is therefore an urgent need to develop an evidence-based framework for the assessment of patients with low back pain in the ED.

The CESER study will try to determine whether any pattern of symptoms can help us work out which patients are very unlikely to have CES. It will also help determine how future patients should be treated when they arrive at an ED with symptoms that could be caused by CES.

Who can participate?
Adults aged 18 and over with suspected CES.

What does the study involve?
After consenting to join the study, participants will be asked to answer a series of short questionnaires about symptoms that can be experienced by people with CES. The questions will relate to pain, sensory changes, as well as bowel and bladder function. The completion of the questionnaires will be undertaken through a secure system on a computer or tablet. It should take about 10-15 minutes.
As part of usual standard care, participants will have an MRI scan and together with the doctor, a treatment plan will be made depending on any findings.
If the participant is then diagnosed with CES, the study team will contact them at 6 weeks and then again at 6 and 12 months after diagnosis. Participants will be asked to answer some further questions about pain, bowel and bladder function. They will also ask about their general quality of life. A web link will be sent for them to complete the questionnaires via email or text message. If participants are unable to access an electronic device, they can be contacted via telephone, or paper questionnaires can be sent out. It should not take more than 10-15 minutes to answer the questions.
If participants are not diagnosed with CES, they will not be asked to complete any further questionnaires. As part of the study, participants' hospital records will be reviewed after 12 months to see if participants had any other diagnoses or treatments related to their back pain.
Regardless of whether participants have been diagnosed with CES or not, they may also be asked if they are willing to provide contact details to be contacted by another researcher at a later date about taking part in an interview to discuss their experience of being assessed for CES. Taking part in the interview is optional, and any decision to take part will not affect inclusion in the CESER study or treatment.

What are the possible benefits and risks of participating?
There is no direct benefit in taking part in the study. The results of the study will help us determine how patients should be diagnosed when they arrive at an ED with symptoms that could be caused by CES.
Taking part in this study will not affect any part of the care participants will receive, so there will be no additional risks in taking part.
As part of the study, participants will be asked questions about their symptoms, which some people might find upsetting. If responding to the questionnaires provokes emotional and upsetting responses, the team will suggest that participants take a break and continue at a later time.

Where is the study run from?
The University of Oxford is sponsoring this study. It is being conducted by a research team at Oxford University led by Professor David Metcalfe, Chief Investigator and Associate Professor of Emergency Medicine.

When is the study starting and how long is it expected to run for?
April 2026 to April 2028.

Who is funding the study?
National Institute for Health and Care Research (NIHR), UK.

Who is the main contact?
Mrs Kylea Draper- Trial Manager - ceser@ndorms.ox.ac.uk

Contact information

Mrs Kylea Draper- Kadoorie
Public, Scientific

Trial Manager, Institute of Trauma, Emergency & Critical Care
Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences
University of Oxford
Research Office 3, Kadoorie Centre - Level 3, John Radcliffe Hospital, Headley Way
Oxford
OX3 9DU
United Kingdom

Phone	+44 01865 223126 (Mon, Tue and Thu Only), +44 07392165324 (Wed and Fri Only)
Email	ceser@ndorms.ox.ac.uk

Prof David Metcalfe
Principal investigator, Scientific

Chief Investigator/Associate Professor
Kadoorie Institute of Trauma, Emergency & Critical Care
Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences
University of Oxford, Kadoorie Centre - Level 3, John Radcliffe Hospital, Headley Way
Oxford
OX3 9DU
United Kingdom

ORCID ID	0000-0003-1008-3105
Email	David.metcalfe@ndorms.ox.ac.uk

Study information

Eligibility

Locations

Countries of recruitment

• United Kingdom
• England
• Scotland
• Wales

Study participating centres

Results and Publications

Study outputs

Additional files

49197_PIS_V2.0_04Mar2026.pdf

Participant information sheet

Editorial Notes

13/03/2026: Trial's existence confirmed by the National Institute for Health and Care Research (NIHR) (UK).