Genesis Chiropractic Spine & Sports Center
5950 S. Willow Dr Suite 200
Greenwood Village, CO 80111
Phone (720) 515-8002
Genesis Chiropractic Spine & Sports Center      

Cauda Equina Syndrome

General Information


  • Cauda Equina syndrome is a rare neurologic syndrome characterized by
    • Low back pain
    • Unilateral or bilateral sciatica
    • Bladder and/or bowel dysfunction
    • Decreased perineal sensation
    • Sexual dysfunction
    • Possible neurologic findings in legs (motor loss, sensory changes, reflex changes)


  • Cauda Equina ("horse's tail" in Latin) is bundle of nerve roots extending from end of spinal cord (conus medullaris and filum terminale) usually located at level of space between first and second lumbar vertebrae


  • Incomplete Cauda Equina syndrome
    • Associated with urinary difficulties such as
      • Altered urinary sensation
      • Loss of urge to void
      • Poor urinary stream
      • Need to strain to urinate

    • Subjective and objective neurologic deficits include
      • Impaired bladder sensation
      • Impaired urethral sensation
      • Impaired rectal sensation and/or objective sensory loss in perineal region (S3-S5)
      • Decreased tone of anal sphincter
      • Reference - Ann R Coll Surg Engl 2009 May;91(4):358 
  • Complete Cauda Equina syndrome characterized by painless urinary retention and overflow incontinence

Who is most affected:

  • Patients with herniated lumbar disks


  • Estimated prevalence in general population ranges from 1 per 33,000 persons to 1 per 100,000 persons
  • Estimated prevalence among patients with low back pain 4 per 10,000 persons
  • Reported in 1%-10% of patients with herniated lumbar disks

Causes and Risk Factors


  • Central or centerolateral disk herniation is most common cause
    • Level of lumbar disk herniations in 322 patients with Cauda Equina syndrome
      • L1-L2 in 27%
      • L2-L3 in 9%
      • L3-L4 in 26%
      • L4-L5 in 16%
      • L5-S1 in 22%
      • Reference - Spine (Phila Pa 1976) 2000 Jun 15;25(12):1515, commentary can be found in Spine (Phila Pa 1976) 2004 Jun 1;29(11):1281
    • Posterior migration of lumbar disk fragment causing Cauda Equina syndrome in case report (Acta Orthop Belg 2009 Jun;75(3):423)
  • Lumbar spinal stenosis
  • Infections (such as meningitis)
  • Iatrogenic causes
    • Postsurgical complications
    • Following anesthesia procedures (or other epidural injections)
    • Postspinal manipulation techniques
    • Spinal arachnoiditis (following dye injection for myelogram)
  • Epidural abscess
  • Congenital malformations (such as spina bifida, diastematomyelia)
  • Tumor (primary or metastatic)
  • Rheumatologic (rheumatoid arthritis, ankylosing spondylitis)
  • Trauma (gunshot wounds, stabbings)
  • Vertebral fractures
  • Hematoma (spinal subdural or spinal epidural)
  • Abdominal aortic dissection (rare cause)


  • Any lesion to Cauda Equina nerve roots (such as compressive or inflammatory lesions, venous congestion, or ischemia) can cause damage to unmyelinated nerve roots

Possible risk factors:

  • History of chronic low back pain for mean 3 years prior to onset of cauda equina syndrome in 82% of 322 patients (Spine (Phila Pa 1976) 2000 Jun 15;25(12):1515), commentary can be found in Spine (Phila Pa 1976) 2004 Jun 1;29(11):1281
  • Lumbar spinal stenosis with bilateral symptomatology may increase risk for development of Cauda Equina (Ann R Coll Surg Engl 2009 May;91(4):358)

  • History of spinal manipulation of low back
    • Based on literature review
    • 61 cases of disk herniation or progression to Cauda Equina syndrome associated with spinal manipulative therapy identified
    • Incidence of Cauda Equina syndrome < 1 per million treatments
    • Reference - J Fam Pract 1996 May;42(5):475, commentary can be found in J Fam Pract 1996 Oct;43(4):333

Complications and Associated Conditions


  • Damage to sacral nerves resulting in permanent
    • Incontinence of bladder
    • Incontinence of bowels
    • Sexual dysfunction
  • Bilateral sciatica and neurologic deficits (Am Fam Physician 2007 Apr 15;75(8):1181), commentary can be found in Am Fam Physician 2008 Mar 15;77(6):746