Carpal Tunnel Syndrome – TN2013

Definition

• Median nerve compression at level of flexor retinuculum

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

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)

Clinical dx

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

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