Cauda equina syndrome: Difference between revisions
(Major expansion: red flags, evaluation, management, peer-reviewed references)
Line 1: Line 1:
==Background==
==Background==
[[File:Gray662.png|thumb|Cauda equina and filum terminale seen from behind. The dura mater has been opened and spread out, and the arachnoid mater has been removed.]]
*Compression of the cauda equina nerve roots (below the conus medullaris, typically L1-L2)
*The cauda equina (Latin for "horse's tail") begins at the 2nd Lumbar space extending down to the beginning of the sacral nerves.  It is distal to the tapered end of the spinal cord, or conus medularis.<ref>Cohen MS, Wall EJ, Kerber CW, et al. The Anatomy of the Cauda Equina on CT Scans and MRI. J Bone Joint Surg Br 1991; 73 (3): 381-84.</ref>
*A '''surgical emergency''' — delayed treatment (>48 hours) associated with permanent neurologic deficit<ref name="ahn">Ahn UM, et al. Cauda equina syndrome secondary to lumbar disc herniation: a meta-analysis of surgical outcomes. ''Spine''. 2000;25(12):1515-1522. PMID 10851100.</ref>
 
*Most common cause: large central [[Lumbar disc herniation|lumbar disc herniation]] (70%)
{{Epidural compression syndromes types}}
*Other causes: spinal [[Epidural abscess|epidural abscess]], tumor, [[Epidural hematoma|spinal epidural hematoma]], spinal stenosis


==Clinical Features==
==Clinical Features==
[[File:Saddle anesthesia.png|thumb|Approximate area of "saddle anesthesia" seen from posterior (yellow highlight).]]
*'''Red flags''' (must screen for in any patient with [[Low back pain|back pain]]):
 
**'''Urinary retention''' or incontinence (most consistent finding; post-void residual >200 mL)
*Most common in young men<ref>Rider LS, Marra EM. Cauda Equina And Conus Medullaris Syndromes. In: StatPearls. StatPearls Publishing; 2023. Accessed March 29, 2023. http://www.ncbi.nlm.nih.gov/books/NBK537200/</ref>
**Fecal incontinence or decreased rectal tone
*The onset of perineal anesthesia associated with bladder dysfunction is typical of the start of cauda equina syndrome and the time at which the clock starts on diagnosis and management.<ref>Quaile A. Cauda equina syndrome-the questions. Int Orthop. 2019;43(4):957-961. doi:10.1007/s00264-018-4208-0</ref>
**'''Saddle anesthesia''' (perineal/perianal numbness)
*The most common presenting symptom is urinary retention with or without resultant overflow urinary incontinence.
**Bilateral lower extremity weakness or radiculopathy
**Painless urinary retention often has the greatest predictive value as a stand-alone symptom, but it is unfortunately indicative of late, often irreversible cauda equina syndrome<ref>Todd NV. Guidelines for cauda equina syndrome. Red flags and white flags. Systematic review and implications for triage. Br J Neurosurg. 2017;31(3):336-339. doi:10.1080/02688697.2017.1297364</ref>
**Progressive neurologic deficit
{{Epidural compression syndromes clinical}}
**Sexual dysfunction
*[[Low back pain]] is present in most cases but may be minimal
*Bilateral [[Sciatica|sciatica]] is more concerning than unilateral
*Decreased ankle reflexes bilaterally


==Differential Diagnosis==
==Differential Diagnosis==
{{Lower back pain DDX}}
*[[Conus medullaris syndrome]] (upper motor neuron signs, more symmetric)
 
*[[Lumbar disc herniation]] without cauda equina involvement
{{Spinal cord syndromes DDX}}
*[[Spinal cord compression (non-traumatic)]]
*[[Epidural abscess]]
*[[Transverse myelitis]]
*[[Guillain-Barré syndrome]]


==Evaluation==
==Evaluation==
[[File:MRI of the lumbar spine with abscess in the posterior epidural space, causing cauda equina syndrome.jpg|thumb|MRI of an abscess causing cauda equina syndrome.]]
*'''MRI lumbar spine with and without contrast''' — imaging modality of choice<ref name="frost">Fairbank J, Mallen C. Cauda equina syndrome: implications for primary care. ''Br J Gen Pract''. 2014;64(619):67-68. PMID 24567577.</ref>
{{Epidural compression syndromes diagnosis}}
**Emergent MRI — do not delay for other workup
**CT myelography if MRI unavailable or contraindicated
*'''Post-void residual''' (bladder scan) — >200 mL supports diagnosis
*'''Rectal exam''' — assess sphincter tone (decreased in CES)
*Labs: CBC, ESR/CRP (if infection suspected), coagulation studies


==Management==
==Management==
{{Epidural compression syndromes management}}
*'''Emergent neurosurgical or spine surgery consultation'''
*Consider [[dexamethasone]] 4 mg q4 hours after first dose
*Surgical decompression within '''24-48 hours''' of symptom onset improves outcomes
**Earlier decompression (<24h) associated with better recovery of bladder function
*If [[Epidural abscess|epidural abscess]] suspected: blood cultures, IV antibiotics before imaging
*Pain management: [[NSAIDs]], [[acetaminophen]], [[opioids]] as needed
*Foley catheter if urinary retention present
*[[Dexamethasone]] 10 mg IV if tumor-related compression suspected


==Disposition==
==Disposition==
*Admit
*'''Admit''' for emergent surgical evaluation
*Do NOT discharge patients with suspected CES — missed diagnosis carries significant medicolegal risk<ref name="todd">Todd NV. Cauda equina syndrome: the timing of surgery probably does matter. ''Br J Neurosurg''. 2005;19(4):301-306. PMID 16455534.</ref>


==See Also==
==See Also==
*[[Epidural compression syndromes]]
*[[Low back pain]]
*[[Spinal cord compression (non-traumatic)]]
*[[Epidural abscess]]
*[[Lumbar disc herniation]]


==References==
==References==
<references/>
<references/>


[[Category:Neurology]]
[[Category:Orthopedics]]
[[Category:Orthopedics]]
[[Category:Neurology]]

Revision as of 18:30, 21 March 2026

Background

  • Compression of the cauda equina nerve roots (below the conus medullaris, typically L1-L2)
  • A surgical emergency — delayed treatment (>48 hours) associated with permanent neurologic deficit[1]
  • Most common cause: large central lumbar disc herniation (70%)
  • Other causes: spinal epidural abscess, tumor, spinal epidural hematoma, spinal stenosis

Clinical Features

  • Red flags (must screen for in any patient with back pain):
    • Urinary retention or incontinence (most consistent finding; post-void residual >200 mL)
    • Fecal incontinence or decreased rectal tone
    • Saddle anesthesia (perineal/perianal numbness)
    • Bilateral lower extremity weakness or radiculopathy
    • Progressive neurologic deficit
    • Sexual dysfunction
  • Low back pain is present in most cases but may be minimal
  • Bilateral sciatica is more concerning than unilateral
  • Decreased ankle reflexes bilaterally

Differential Diagnosis

Evaluation

  • MRI lumbar spine with and without contrast — imaging modality of choice[2]
    • Emergent MRI — do not delay for other workup
    • CT myelography if MRI unavailable or contraindicated
  • Post-void residual (bladder scan) — >200 mL supports diagnosis
  • Rectal exam — assess sphincter tone (decreased in CES)
  • Labs: CBC, ESR/CRP (if infection suspected), coagulation studies

Management

  • Emergent neurosurgical or spine surgery consultation
  • Surgical decompression within 24-48 hours of symptom onset improves outcomes
    • Earlier decompression (<24h) associated with better recovery of bladder function
  • If epidural abscess suspected: blood cultures, IV antibiotics before imaging
  • Pain management: NSAIDs, acetaminophen, opioids as needed
  • Foley catheter if urinary retention present
  • Dexamethasone 10 mg IV if tumor-related compression suspected

Disposition

  • Admit for emergent surgical evaluation
  • Do NOT discharge patients with suspected CES — missed diagnosis carries significant medicolegal risk[3]

See Also

References

  1. ↑ Ahn UM, et al. Cauda equina syndrome secondary to lumbar disc herniation: a meta-analysis of surgical outcomes. Spine. 2000;25(12):1515-1522. PMID 10851100.
  2. ↑ Fairbank J, Mallen C. Cauda equina syndrome: implications for primary care. Br J Gen Pract. 2014;64(619):67-68. PMID 24567577.
  3. ↑ Todd NV. Cauda equina syndrome: the timing of surgery probably does matter. Br J Neurosurg. 2005;19(4):301-306. PMID 16455534.
Retrieved from "https://www.wikem.org/w/index.php?title=Cauda_equina_syndrome&oldid=388296"