Cauda Equina Syndrome

16 Mar

submitted by Christina Brown, M.D. 


Definition – Compression of lumbar and sacral nerve fibers in cauda equina region


  • Neoplasm
  • IV drug use
  • Immunocompromised state.


  • Herniated disc most common:
    • L4–L5 discs > L5–S1 > L3–L4
    • Most common in 4th and 5th decades of life
    • Mass effect from: Myeloma, lymphoma, sarcoma, meningioma, neurofibroma, hematoma
    • Spine metastases (breast, lung, prostate, thyroid, renal)
    • Epidural abscess (especially in IV drug users
  • Blunt trauma
  • Penetrating trauma



  • Low back pain
  • Sciatica/radicular pain (unilateral or bilateral)
  • Lower extremity numbness or weakness
  • Difficulty ambulating owing to weakness or pain
  • Bladder or rectal dysfunction (Retention or incontinence)


Physical Exam

  • Lumbosacral tenderness
  • Lower extremity sensory or motor deficits (May be asymmetric)
  • Decreased foot dorsiflexion strength
  • Decreased quadriceps strength
  • Decreased deep tendon reflexes
  • Saddle hypalgesia or anesthesia
  • Decreased anal sphincter tone

Postvoid residual volume (PVR):

  • Estimate by bladder catheterization or using US.
  • >100 mL is considered abnormal.
  • Residual increases with age.


Labs – Depends on differential diagnosis. Options include CBC, urinalysis, ESR, and C reactive protein (CRP)

IMAGING – MRI of spine is definitive study. CT myelogram if MRI unavailable

ED Treatment/Procedures:

  • Immediate neurosurgical consultation in all cases
  • Initiate antibiotics for epidural abscess in consultation with neurosurgery.
  • Controversy exists regarding urgency of decompression:
    • Recommendations range from within 6 hr of onset to within 24 hr.



  • All patients with acute cauda equina syndrome must be admitted to neurosurgical service.
  • Patients have good prognosis with rapid surgical decompression.
  • Treatment should not be delayed.
  • Patients presenting late (>48 hr) also benefit from surgical decompression.



1. Fraser S, Roberts L, and Murphy E.: Cauda equina syndrome: A literature review of its definition and clinical presentation. Arch Phys Med Rehabil. 2009; 90(11):1964–1968.
2. Hussain S A, Gullan R W, and Chitnavis B P.: Cauda equina syndrome: Outcome and implications for management. Br J Neurosurg. 2003; 17(2):164–167.
3. Shapiro S.: Medical realities of cauda equina syndrome secondary to lumbar disc herniation. Spine. 2000; 25(3):348–352.
4. Schaider, J. & Barkin, R. & Hayden, S. & Wolfe, R. & Barkin, A. & Shayne, P. & Rosen, P. (2011). Cauda Equina Syndrome. Rosen & Barkin’s 5 Minute Emergency Medicine Consult.



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