Carpal Tunnel Syndrome

Question 1

What is Carpal tunnel syndrome?

Answer 1

CTS, refers to the symptom complex brought on by compression of the median nerve in the carpal tunnel.

Question 2

What is the function of the median nerve in the hand?

Answer 2

MOTOR TO: flex fingers II and III at MCP, extend fingers II and III at Ips, thumb adduction, flexion and opposition of the thumb. SENSORY TO: index finger, middle finger, half the ring finger, and palmar surface of thumb.

Question 3

What is the anatomy of the carpal tunnel?

Answer 3

Formed by the flexor retinaculum superiorly, and the carpal bones inferiorly.

Question 4

What is the aetiology of CTS? (x7)

Answer 4

• Idiopathic in 43% of cases
• Tenosynovitis secondary to overuse, RA or other inflammatory rheumatic diseases
• Infiltrative diseases of the canal (leading to increased soft tissue in the canal and subsequent compression): amyloidosis, myeloma myxoedema, acromegaly
• Bone involvement in the wrist: osteoarthritis, fracture, tumour
• Fluid retention states: pregnancy, nephrotic syndrome
• Obesity
• Menopause
• Diabetes

Question 5

What is the epidemiology of CTS: Gender? Age?

Answer 5

Females between 40 and 60.

Question 6

What are the signs and symptoms of CTS? (x3) Onset?

Answer 6

• Gradual onset (radiculopathy is acute)
• Tingling, loss of sensation and pain in the hand and fingers (first three phalanges), worse at night
• Aching wrist
• Weakness and clumsiness in hand

Question 7

What are the investigations for CTS?

Answer 7

EMG: diagnostic of choice; slowing of condution in median sensory nerves across carpal tunnel in the context of normal conduction elsewhere