What is carpal tunnel syndrome and how is it managed?

Carpal Tunnel Syndrome: Diagnosis and Management

Carpal tunnel syndrome (CTS) is characterized by compression of the median nerve at the wrist, typically presenting with pain, numbness, and tingling in the median nerve distribution, which worsens at night and can be associated with conditions like rheumatoid arthritis, amyloidosis, and pregnancy. 1, 2

Clinical Presentation

• Pain pattern: Typically worse at night and improves during the day (contrary to option A in the question)
• Associated conditions: Commonly associated with rheumatoid arthritis and amyloidosis (option B is correct)
• Pregnancy-related: CTS frequently occurs during pregnancy due to fluid retention (option C is correct)
• Symptoms: Pain, paresthesia, and numbness in the distribution of the median nerve (thumb, index, middle finger, and radial half of the ring finger)
• Late findings: Thenar muscle atrophy indicates advanced disease 1, 3

Diagnostic Approach

Clinical Evaluation

• Provocative tests:
  • Phalen test (wrist flexion)
  • Tinel sign (tapping over the median nerve)
  • These tests have variable sensitivity and specificity 3

Diagnostic Testing

• Ultrasound: Highly sensitive and specific for CTS diagnosis

  • Key measurement: Cross-sectional area of median nerve (>15 mm² is diagnostic)
  • Can identify nerve enlargement, flattening, and anatomic variants 1, 4

• Electrodiagnostic studies:

  • Considered the primary diagnostic method
  • Includes nerve conduction studies and electromyography
  • Particularly useful in atypical presentations 1, 3

• Imaging:

  • MRI: Not routinely indicated but may help in complex cases
  • CT, bone scan, and arthrography: Not recommended for CTS diagnosis 4, 1

Management Algorithm

1. Mild Symptoms

• First-line treatment: Wrist splinting for 6-12 weeks
  • Night-only splinting is as effective as continuous wear
  • Neutral position is more effective than extension 1, 3

2. Persistent Mild/Moderate Symptoms

• Add corticosteroid injection:
  • Provides greater symptom improvement than splinting at 6 weeks
  • Similar outcomes to splinting at 6 months 1, 3

3. Severe Symptoms or Failed Conservative Treatment

• Surgical decompression indicated for:
  • Objective weakness
  • Sensory deficits
  • Thenar atrophy
  • Both endoscopic and open carpal tunnel release techniques are equally effective 1, 3

Special Considerations

Pregnancy-Related CTS

• Often resolves after delivery
• Conservative management is preferred during pregnancy
• Splinting and activity modification are first-line approaches 2

Work-Related Factors

• Ergonomic assessment and modifications are important
• Avoid vibratory tools and repetitive wrist movements
• Consider wrist splints when sleeping to avoid excessive wrist flexion 4, 2

Warning Signs

• Thenar atrophy suggests long-standing compression requiring surgical intervention
• May result in incomplete recovery even after decompression 1

Common Pitfalls

• Misdiagnosing other conditions with similar symptoms (cervical radiculopathy, pronator syndrome)
• Approximately 6% of CTS cases have concurrent pronator syndrome 1
• Delaying surgical intervention in cases with muscle atrophy or severe symptoms
• Over-reliance on normal nerve conduction studies to exclude CTS (a normal test does not necessarily rule out CTS) 3