Carpal tunnel syndrome

Background

  • Also known as "Median Mononeuropathy"
  • Most common focal mononeuropathy
  • Results from compression of median nerve at wrist where it traverses the carpal tunnel
  • Median nerve provides sensation to the palmar aspect digits 1-3 and radial side of 4th
  • Etiology: repetitive wrist flexion/extension, trauma, edema

Risk factors

Clinical Features

History

  • Pain, paresthesia, and numbness in distribution of median nerve
    • Palmar aspect of thumb, index, middle, and radial aspect of ring finger
  • Awakening at night with burning pain and tingling in hand

Physical

  • Sensation testing
    • Most specific - splitting of 4th digit in which medial aspect of 4th digit normal and lateral aspect abnormal
    • Most sensitive - abnormal sensation of distal palmar tip of 2nd digit
  • LOAF muscle weakness as compared to other hand - Lumbricals, with thumb Opposition, Abduction, Flexion
  • Tinel sign - poorly sensitive and specific
    • Tapping on palmar aspect of wrist reuslts in electric shock sensation shooting into hand
    • SN 0.50 and SP 0.77[1]
  • Phalen maneuver
    • Holding wrists in flexion for 60 seconds evokes or worsens symptoms
    • SN 0.68 and SP 0.73[2]
  • Durkan sign
    • Manual compression of carpal tunnel reproduces symptoms after 30 seconds
    • SN 0.64 and SP 0.83
    • More sensitive and specific than Tinel and Phalen in earlier studies[3]
  • Hand Elevation Test
    • Performed by having patient elevated both hands above the head
    • Positive if paresthesia, numbness, or dull pain felt within two minutes
    • SN 0.87 and SP 0.89[4]
  • May see atrophy of thenar eminence in advanced cases

Differential Diagnosis

By Type of Lestion

Proximal Lesion

Distal Lesion

  • Ulna neuropathy

Systemic condition

Upper extremity peripheral nerve syndromes

Median Nerve Syndromes

Ulnar Nerve Syndromes

Radial Nerve Syndromes

Proximal Neuropathies

Other

Management

  • See this American Academy of Orthopedic Surgeons clinical decision tool for treatment options and disposition - CTS guidelines
  • Behavioral modification
  • Wrist splint with wrist in neutral position
  • NSAIDs (although not clearly effective)
  • Diuretics (if edema is significant contributor to patient's symptoms)

Disposition

  • Discharge

See Also

References

  1. MacDermid JC and Wessel J. Clinical diagnosis of carpal tunnel syndrome: a systematic review. J Hand Ther. 2004; 17(2):309.
  2. MacDermid JC and Wessel J. Clinical diagnosis of carpal tunnel syndrome: a systematic review. J Hand Ther. 2004; 17(2):309.
  3. Durkan, JA. A new diagnostic test for carpal tunnel syndrome, The Journal of Bone and Joint Surgery. 1991; 73(4):535–538.
  4. Ma H, Kim I. The diagnostic assessment of hand elevation test in carpal tunnel syndrome. J Korean Neurosurg Soc. 2012;52(5):472-475. doi:10.3340/jkns.2012.52.5.472