Carpal Tunnel


  • Compression median nerve beteeen carpal bones and flexor retinaculum
  • M:F = 1:3. Bilateral in 70%
  • Genetic component
  • Assoc pregnancy, overuse, trauma, ↓T4, CRF, DM, arthropathies, obesity


  • Intermittant pain/altered sensation in radial 3½ digits
  • Sometimes assoc. forearm/arm/shoulder pain
  • Worse at night or with overuse
  • ↓grip strengt and ↓sensation med N distribution
  • ↓LOAF muscle power (↓thumb abduction)
  • Thenar wasting late
  • Tinel's sign = tingling with percussion over carpal tunnel
  • Phalen's test = tingling with wrists flexed to 90° x 1 min
  • Durkan's test = Tingling with 3 finger pressure on carpal tunnel x30 sec

Differential Dx

ASSUMING NO RECENT TRAUMA (local haematoma etc)

  • Polyneuropathy - particularly diabetic (check BM in all)
  • Early arthropathy / mono-arthritis (consider RhF or autoantibodies)
  • Cervical radiculopathy (neck movement)
  • Hypothyroid (ask GP to check TFTs)
  • Vibration white hand syndrome (Hx should be a giveaway!)
  • Motor neuron disease does not have sensory component


  • GP to arrange EMG studies
  • GP to refer to hand / oirtho suegeon


  • Treat reversible causes
  • Wrist splint (in 0° flexion) particularly at night
  • Consider steroid injection into tunnel (NOT the nerve!) - transient relief
  • Transient relief with PO steroids
  • GP to refer for surgery

Content by Dr Íomhar O' Sullivan . Last review Dr ÍOS 19/06/21.