Objective Atraumatic back pain is an increasingly common presentation to the ED. A minority of these cases will have significant structural pathology, resulting in acute cauda equina compression (CEC). Although clinicians often look for ‘red flags’ to identify potential CEC, the prognostic accuracy of these presenting symptoms and clinical examination findings is unclear. We sought to evaluate the accuracy of individual clinical features in a large cohort of ED patients with atraumatic backpain and reference standard imaging, for the diagnosis of CEC.
Methods A retrospective case note review from 2014 to 2018 within an established ED atraumatic back pain pathway, undertaken at the largest tertiary spinal referral centre in the UK. We analysed routine data, collected prospectively by treating clinicians within a structured electronic health record clinical proforma. Data on signs and symptoms in 996 patients with suspected CEC referred for definitive MRI over a 4-year study period were extracted and compared against a final reference standard diagnosis.
Results We identified 111 patients with radiological evidence of CEC within the cohort referred for definitive imaging (111/996, 11.1%), of whom 109 (98.2%) underwent operative intervention. Patients with CEC were more likely to present with bilateral leg pain (OR=2.2), dermatomal sensory loss (OR 1.8) and bilateral absent ankle or ankle and knee jerks (OR=2.9). Subjective weakness was found to be associated with CEC on univariate but not multivariate analysis. We found no relationship between digital rectal examination findings and the diagnosis of CEC.
Conclusions In our cohort, factors independently associated with CEC diagnosis on MRI included bilateral leg pain, dermatomal sensory loss. Loss of lower limb reflexes was strongly suggestive of CES (likelihood ratio 3.4 on multivariate logistic regression). Our findings raise questions about the diagnostic utility of invasive digital rectal examination.
- non-traumatic problems
- spine non-trauma
- clinical assessment
- clincial management
Data availability statement
Data are available upon reasonable request.
Statistics from Altmetric.com
Handling editor Loren De Freitas
Contributors Overall guarantor: MA. Conception and design: MA and IS. Administrative support: MA and CMC-L. Provision of study materials or patients: MA, DEH, IS. Collection and assembly of data: MA, RC. Data analysis and interpretation: RC. Manuscript writing: VC, DEH, MA. Final approval of manuscript: all authors.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.