Levesque L1, Dionne N1, Trehan N1, Adefolarin A1, Dave W1, Sadi J1, Kunzelman D1, Finucane L2
1Western University, Department of Health Sciences Physical Therapy, London, Canada, 2Sussex MSK Partnership, Brighton, United Kingdom
Background: Cauda equina syndrome (CES) is a rare condition that affects the nerves that supply the bladder, bowel and sexual function. The most common cause is an intervertebral disc herniation at the L4/5 level causing compromise of the CE. The estimated prevalence is 0.04 among people with low back pain. CES remains challenging to diagnose. Clinicians use red flags to screen for this condition but their diagnostic accuracy has not yet been established. For a potential diagnosis of CES, one or more of the following red flags should be present in the presence of back pain and/or leg pain; saddle anesthesia/perineal numbness, urinary retention/overflow incontinence, fecal incontinence and reduced anal sphincter tone.
Purpose: To review the available evidence on the diagnostic accuracy of red flags to clinically identify CES when compared to the reference standard of Magnetic Resonance Imaging (MRI).
Methods: Primary diagnostic studies, published in English; comparing red flags for CES; to MRI as a reference standard; in humans; older than 18 years. Data Sources included Embase, Scopus, Ovid Medline, Ovid Healthstar, Amed and CINAHL from inception to January 30, 2018 and hand search of reference lists of relevant studies, government clinical trials and expert personal files.
Data extraction was conducted by four assessors, and three independent assessors conducted the assessment of study quality using a modified QUADAS-2 tool. Diagnostic accuracy statistics were a pplied to the identified data. Pooled analysis was performed using Meta-DiSc, version 1.4.Moderator analyses were planned for the pooled results.
Results: We included seven studies set in secondary or tertiary care settings; evaluating the red flags for CES, compared to MRI. Diagnostic data could be pooled for red flags (reduced anal tone, leg pain, back pain, saddle anaesthesia, urinary retention, urinary incontinence, bowel incontinence) from six of seven studies. We identified significant heterogeneity, as demonstrated by the high values of I-square and chi-square. The pooled sensitivity for the red flags (signs and symptoms) ranged from 0.19 (95% CI 0.09 to 0.33) to 0.43 (95% CI 0.30 to 0.56). The pooled specificity ranged from 0.62 (95% CI 0.59 to 0.73) to 0.88 (95% CI 0.85 to 0.92).
Conclusion(s): Despite the poor diagnostic accuracy, evidence supports the use of red flags in assisting with the crucial early identification of CES. Whenever CES is suspected, prompt referral should be made for MRI.
Implications: CES is rare but can have devastating consequences for patients if not acted on in a timely manner. The findings of this SR will help to raise the awareness of this condition and the importance of acting promptly if there is a suspicion of CES. This SR forms part of a wider piece of International research, which will look to develop a clinical framework for clinicians when faced with possible serious pathology of the spine.
Keywords: Cauda equina, red flags, MRI
Funding acknowledgements: Not applicable
Purpose: To review the available evidence on the diagnostic accuracy of red flags to clinically identify CES when compared to the reference standard of Magnetic Resonance Imaging (MRI).
Methods: Primary diagnostic studies, published in English; comparing red flags for CES; to MRI as a reference standard; in humans; older than 18 years. Data Sources included Embase, Scopus, Ovid Medline, Ovid Healthstar, Amed and CINAHL from inception to January 30, 2018 and hand search of reference lists of relevant studies, government clinical trials and expert personal files.
Data extraction was conducted by four assessors, and three independent assessors conducted the assessment of study quality using a modified QUADAS-2 tool. Diagnostic accuracy statistics were a pplied to the identified data. Pooled analysis was performed using Meta-DiSc, version 1.4.Moderator analyses were planned for the pooled results.
Results: We included seven studies set in secondary or tertiary care settings; evaluating the red flags for CES, compared to MRI. Diagnostic data could be pooled for red flags (reduced anal tone, leg pain, back pain, saddle anaesthesia, urinary retention, urinary incontinence, bowel incontinence) from six of seven studies. We identified significant heterogeneity, as demonstrated by the high values of I-square and chi-square. The pooled sensitivity for the red flags (signs and symptoms) ranged from 0.19 (95% CI 0.09 to 0.33) to 0.43 (95% CI 0.30 to 0.56). The pooled specificity ranged from 0.62 (95% CI 0.59 to 0.73) to 0.88 (95% CI 0.85 to 0.92).
Conclusion(s): Despite the poor diagnostic accuracy, evidence supports the use of red flags in assisting with the crucial early identification of CES. Whenever CES is suspected, prompt referral should be made for MRI.
Implications: CES is rare but can have devastating consequences for patients if not acted on in a timely manner. The findings of this SR will help to raise the awareness of this condition and the importance of acting promptly if there is a suspicion of CES. This SR forms part of a wider piece of International research, which will look to develop a clinical framework for clinicians when faced with possible serious pathology of the spine.
Keywords: Cauda equina, red flags, MRI
Funding acknowledgements: Not applicable
Topic: Musculoskeletal: spine
Ethics approval required: No
Institution: Western University
Ethics committee: Western University Health Science Reseach Ethics Board (HSREB)
Reason not required: The project was a systematic review and therefore did not require ethics approval
All authors, affiliations and abstracts have been published as submitted.
