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Cauda Equina Syndrome, Emergency Medicine

Basics

Description

Compression of lumbar and sacral nerve fibers in cauda equina region:

  • Nerve fibers below conus medullaris
  • Fibers end at L1-L2 interspace.

Risk Factors

  • Neoplasm
  • IV drug use
  • Immunocompromised state
  • Trauma

Etiology

  • Herniated disc most common:L4-L5 discs > L5-S1 > L3-L4Most common in 4th and 5th decades of life
  • Mass effect from:Myeloma, lymphoma, sarcoma, meningioma, neurofibroma, hematomaSpine metastases (breast, lung, prostate, thyroid, renal)Epidural abscess (especially in IV drug users)
  • Blunt trauma
  • Penetrating trauma
  • Spinal anesthesia

Diagnosis

Signs and Symptoms

History

  • 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 (LS) tenderness
  • Lower-extremity sensory or motor deficits:
  • Decreased foot dorsiflexion strength
  • Decreased quadriceps strength
  • Decreased deep tendon reflexes
  • Saddle hypalgesia or anesthesia
  • Decreased anal sphincter tone

Essential Workup

  • Neurologic exam most essential:Straight-leg raiseLas ¨gue sign:With patient supine, flex hip and dorsiflex foot.Pain or spasm in posterior thigh indicates nerve irritation.Perineal sensationRectal toneAnal wink: Reflex contraction of external anal sphincter with gentle stroking of skin lateral to anus
  • Postvoid residual volume:Estimate by bladder catheterization or using US.>50-100 mL is considered abnormal.Residual increases with age.Diagnosis unlikely if normal

Diagnosis Tests & Interpretation

Lab

  • Based on differential diagnoses
  • CBC, urinalysis, ESR, and C-reactive protein (CRP)

Imaging

  • Radiographs of LS spine
  • MRI of spine is definitive study.
  • CT myelogram if MRI unavailable

Differential Diagnosis

  • Osteoarthritis, LS strain, sciatica
  • Vertebral fracture (pathologic and nonpathologic)
  • Osteomyelitis
  • Spinal epidural abscess
  • Conus medullaris or higher cord compression
  • Ankylosing spondylitis, spinal stenosis
  • Abdominal aortic aneurysm dissection
  • Vascular claudication
  • Hip pathology
  • Acute transverse myelitis

Treatment

Pre-Hospital

  • Manage airway and traumatic injuries as indicated.
  • If evidence of trauma, patient should be transported with full spine immobilization.

Even in nontrauma patient, consider spinal immobilization given possibility of unstable lesion.

Initial Stabilization/Therapy

  • Spine immobilization if trauma or unstable spine lesion suspected
  • Analgesia
  • NPO until evaluated by neurosurgery

Ed Treatment/Procedures

  • Repeat neurologic exams to detect progression.
  • For acute spinal cord trauma (<8 hr), begin high-dose methylprednisolone protocol.
  • 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.

Medication

  • Methylprednisolone (high-dose steroid protocol): 30 mg/kg IV bolus, then 5.4 mg/kg/h infusion over next 23 hr. Should be started within 8 hr of injury.

Follow-Up

Disposition

Admission Criteria

  • 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.

Discharge Criteria

Patients with established cauda equina syndrome with prior complete evaluation and no new neurologic deficits may be discharged with close follow-up with their neurosurgeon.

Pearls and Pitfalls

Ideally, diagnose patients in early phase before irreversible neurologic dysfunction:

  • Back pain out of proportion
  • Fever and back pain
  • Back pain in high-risk groups; screen with ESR/CRP when infection suspected

Additional Reading

  • Fraser S, Roberts L, Murphy E. Cauda equina syndrome: A literature review of its definition and clinical presentation. Arch Phys Med Rehabil. 2009;90(11):1964-1968.
  • Hussain SA, Gullan RW, Chitnavis BP. Cauda equina syndrome: Outcome and implications for management. Br J Neurosurg. 2003;17(2):164-167.
  • Kingwell SP, Curt A, Dvorak MF. Factors affecting neurological outcome in traumatic conus medullaris and cauda equina injuries. Neurosurg Focus. 2008;25(5):E7.
  • Ma B, Wu H, Jia LS, et al. Cauda equina syndrome: A review of clinical progress. Chin Med J (Engl). 2009;122(10):1214-1222.
  • Mauffrey C, Randhawa K, Lewis C, et al. Cauda equina syndrome: An anatomically driven review. Br J Hosp Med (Lond). 2008;69(6):344-347.
  • Olivero WC, Wang H, Hanigan WC, et al. Cauda equina syndrome (CES) from lumbar disc herniations. J Spinal Disord Tech. 2009;22(3):202-206.
  • Rooney A, Statham PF, Stone J. Cauda equina syndrome with normal MR imaging. J Neurol. 2009;256(5):721-725.
  • Todd NV. An algorithm for suspected cauda equina syndrome. Ann R Coll Surg Engl. 2009;91(4):358-359; author reply 359-360.

Codes

ICD9

  • 344.6 Cauda equina syndrome
  • 344.60 Cauda equina syndrome without mention of neurogenic bladder
  • 344.61 Cauda equina syndrome with neurogenic bladder

ICD10

G83.4 Cauda equina syndrome

SNOMED

  • 192970008 Cauda equina syndrome (disorder)
  • 192971007 cauda equina syndrome not affecting bladder (disorder)
  • 12454008 cauda equina syndrome with neurogenic bladder (disorder)
  • 230614002 Injury of cauda equina (disorder)
  • 126963001 Neoplasm of cauda equina (disorder)