What are the symptoms of cauda equina syndrome?

Symptoms of Cauda Equina Syndrome

The key symptoms of cauda equina syndrome include bilateral radicular pain, urinary dysfunction with preserved control, perineal sensory changes, and bowel/sexual dysfunction, which require immediate MRI and surgical evaluation to prevent permanent neurological damage. 1, 2

Early Warning Signs (True "Red Flags")

Cauda equina syndrome (CES) can be classified into progressive stages, with early recognition being critical for preventing permanent disability:

Suspected CES (CESS)

• Bilateral radiculopathy (bilateral radicular pain and/or bilateral sensory disturbance or motor weakness) 1
• New changes in bladder function but with preserved control (may include): 1, 2
  • Impaired bladder or urethral sensation
  • Hesitancy
  • Poor stream
  • Urgency of micturition

Incomplete CES (CESI)

• Objective evidence of CES with retained voluntary control of micturition 1
• Subjective and/or objective loss of perineal sensation 1
• Reduced anal tone 1, 2

Late Signs ("White Flags")

These indicate severe, potentially irreversible damage has already occurred:

• Painless urinary retention (most sensitive finding - 90% sensitivity) 2
• Complete loss of bladder control/urinary incontinence 1
• Complete perineal anesthesia 1
• Patulous anus (complete loss of anal tone) 1
• Sexual dysfunction 1, 2

Additional Associated Symptoms

• Low back pain with or without bilateral sciatica 2, 3
• Lower extremity weakness 2, 3
• Lower extremity sensory changes 3
• Altered reflexes in lower extremities 2

Important Clinical Considerations

• No single symptom or sign has sufficient positive predictive value for diagnosing CES; a combination of symptoms and signs must be evaluated 1
• Urinary retention is the most sensitive finding (90% sensitivity) 2
• The British Journal of Neurosurgery emphasizes that many patients are referred too late when neurological damage is already irreversible 1
• Symptoms may develop either suddenly or gradually, and most patients do not present with all symptoms 3

Diagnostic Algorithm

1. Assess for early warning signs:

   • Bilateral radicular pain/sensory changes
   • New changes in bladder function with preserved control
   • Subjective perineal sensory changes

2. Perform targeted examination:

   • Perineal/saddle sensation testing
   • Anal tone assessment
   • Lower extremity strength, sensation, and reflexes
   • Post-void bladder volume assessment (if available) 3

3. Immediate action if any red flags present:

   • Emergency MRI lumbar spine (gold standard) 2
   • Urgent surgical consultation 1, 2

Prognosis Based on Presentation Timing

• Patients treated at CESS stage typically avoid long-term bladder, bowel, or sexual dysfunction 1
• Patients treated at CESI stage typically achieve normal or socially normal bladder and bowel control, though may have residual sexual dysfunction 1
• Patients with complete CES with retention (CESR) often have severe impairment with paralyzed bladder requiring catheterization, bowel dysfunction requiring manual evacuation, and sexual dysfunction 1
• Only a minority of patients with severe deficits return to work 1

Early recognition of cauda equina symptoms and immediate imaging and surgical consultation are essential to prevent devastating long-term neurological consequences.