Background
- 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
Clinical
- 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
Investigations
- GP to arrange EMG studies
- GP to refer to hand / oirtho suegeon
Management
- 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