Carpal Tunnel Syndrome – TN2013

Definition

• Median nerve compression at level of flexor retinuculum

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Etiology

• Primary cause: idiopathic
• Secondary causes:
  1. Space occupying lesions: tumors, hypertrophic synovial tissue, fracture callus, osteophytes
  2. Metabolic / physiological: pregnancy, hypothyroidism, acromegaly, RA
  3. Infections
  4. Neuropathies: associated with DM or EtOH
  5. Familial disorders
  6. Job/hobby related repetitive trauma – with forced wrist flexion

Female:male = 4:1

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Symptoms:

1. Sensory loss in median nerve distribution – radial 3.5 digits
2. discriminative touch often lost first, then light touch and 2-pt discrimination, esp fingertips
3. Pt awakened at night with numb/painful hand, relieved by shaking/dangling/rubbing
4. Advanced cases: thenar wasting / weakness

Signs:

1. Tinel’s sign (nerve percussion – tingling)
2. Phalen’s sign (wrist flexion induces symptoms)

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Clinical dx

• EMG may confirm, but don’t not exclude dx

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Tx

1. Avoid repetitive wrist and hand motion, wrist splints in neutral position at night
2. NSAIDs, local corticosteroids injection, oral corticosteroids
3. Surgical decompression: transverse carpal ligament incision
   • Indication for Sx: numbness & tingling +/- sensory loss, weakness +/- mm atrophy, unresponsive to conservative measures
   • C/I: injury to median motor branch, palmar cutaneous branch or superficial transverse vascular arch, local pain, scar formation