What are the symptoms of cauda equina syndrome?

Symptoms of Cauda Equina Syndrome

Urinary retention is the most frequent and sensitive finding (90% sensitivity) in cauda equina syndrome, and its presence should prompt immediate evaluation and management to prevent permanent neurological damage. 1

Key Symptoms and Clinical Presentation

Cauda equina syndrome (CES) is a rare but serious neurological condition caused by compression of the nerve roots (cauda equina) in the lower spinal canal. The most common symptoms include:

Primary Symptoms

• Urinary dysfunction (90% sensitivity)

  • Urinary retention
  • Difficulty initiating urination
  • Decreased urinary sensation
  • Overflow incontinence 1

• Bowel dysfunction

  • Fecal incontinence
  • Decreased rectal tone 2, 3

• Saddle anesthesia

  • Numbness in the perineal/genital region
  • Loss of sensation in areas that would contact a saddle 1, 3

• Sexual dysfunction 3

Associated Symptoms

• Low back pain (most common physical finding) 1
• Bilateral sciatica (radiating leg pain) 3
• Lower extremity sensory changes or numbness 1
• Lower extremity weakness (may be bilateral) 2
• Absent or diminished lower limb reflexes 1

Diagnostic Significance

The probability of cauda equina syndrome is extremely low (approximately 1 in 10,000) in patients without urinary retention 1. However, when present, CES requires urgent evaluation and management:

• Symptoms may develop suddenly or gradually 3
• Most patients do not present with all symptoms simultaneously 3
• Isolated symptoms have poor sensitivity, requiring clinicians to maintain high suspicion 3
• Post-void bladder volume assessments can assist in evaluation 3

Common Causes

1. Lumbar disc herniation (most common at L4-L5 and L5-S1 levels) 1
2. Neoplasms (primary or metastatic) 4
3. Trauma (including fractures and dislocations) 5, 6
4. Infection/inflammation 1
5. Spinal stenosis 1
6. Hemorrhage 1

Clinical Pitfalls to Avoid

• Delayed diagnosis - Often leads to poor prognosis 3
• Attributing symptoms to common postoperative findings - Maintain high index of suspicion in postoperative spine patients with back/leg pain refractory to analgesia, especially with urinary retention 2
• Relying on a single symptom - The full syndrome includes multiple symptoms, but patients rarely present with all features 3
• Missing subtle early signs - Initial symptoms can be subtle and easily overlooked 2

Management Approach

When cauda equina syndrome is suspected:

1. Obtain urgent MRI of the lumbar spine (preferred initial study) 1
2. If MRI is unavailable, CT lumbar spine without IV contrast can assess for cauda equina compression 1
3. Urgent surgical decompression is the standard treatment 2, 5, 3

Remember that cauda equina syndrome represents a true surgical emergency, and early diagnosis and intervention are critical to prevent permanent neurological damage.