Carpal Tunnel

Question 1

Describe the mechanism by which pain is caused in carpal tunnel syndrome

Answer 1

compression of median nerve in the carpal tunnel.

Question 2

Symptoms of carpal tunnel syndrome which patients may mention in the history

Answer 2

pain/pins and needles in thumb, index, middle finger
symptoms may ‘ascend’ proximally
patient shakes his hand to obtain relief, classically at night

Question 3

Findings on examination in carpal tunnel

Answer 3

• weakness of thumb abduction (abductor pollicis brevis)
• wasting of thenar eminence
• Tinel’s sign: tapping causes paraesthesia
• Phalen’s sign: flexion of wrist causes symptoms

Question 4

Name the clinical sign:

tapping over median nerve causes paraesthesia

Answer 4

Tinel’s sign

Question 5

Name the clinical sign:

flexion of wrist reproduces carpal tunnel symptoms

Answer 5

Phalen’s sign

Question 6

Causes of carpal tunnel syndrome

Answer 6

idiopathic
pregnancy
oedema e.g. heart failure
lunate fracture
rheumatoid arthritis

Question 7

Signs of carpal tunnel on electrophysiology

Answer 7

motor + sensory: prolongation of the action potential

Question 8

Management of carpal tunnel syndrome

Answer 8

Mild = Conservative
- wrist splints at night: useful if pregnant
- corticosteroid injections my help

Severe/persistent symptoms:
- surgical decompression (flexor retinaculum division)