Wrist/Hand: Carpal tunnel syndrome

Question 1

Define carpal tunnel syndrome

Answer 1

Carpal tunnel syndrome refers to the symptom complex brought on by compression of the median nerve in the carpal tunnel

Question 2

Explain the aetiology/risk factors of carpal tunnel syndrome

Answer 2

Symptoms are caused by compression of the median nerve as it runs through the carpal tunnel

Usually IDIOPATHIC

May be SECONDARY to:
Tenosynovitis (e.g. in rheumatoid arthritis)
Infiltrative diseases of the canal/increased soft tissue (e.g. amyloidosis, acromegaly)
Bone involvement in the wrist (e.g. osteoarthritis, fracture)
Fluid retention states (e.g. pregnancy, nephrotic syndrome)
Other (e.g. obesity , menopause, diabetes)

Question 3

Summarise the epidemiology of carpal tunnel syndrome

Answer 3

Prevalence: 2.7%

Lifetime risk of 10%

Question 4

Recognise the presenting symptoms of carpal tunnel syndrome

Answer 4

Tingling and pain in the hand and fingers (not little finger)
Weakness and clumsiness of the hand

Question 5

Recognise the signs of carpal tunnel syndrome on physical examination

Answer 5

Sensory impairment in the median nerve distribution
Weakness and wasting of thenar eminence

Tinel’s Sign-tapping the carpal tunnel causes symptoms
Phalen’s Test-flexion of the wrist for 1 min may cause symptoms
(Tests aren’t great)

Look out for signs of the underlying cause (e.g. acromegaly, hypothyroidism)

Question 6

Identify appropriate investigations for carpal tunnel syndrome

Answer 6

Clinical Diagnosis

Bloods
TFTs
ESR
•
Nerve Conduction Study (not usually necessary)
Shows impaired median nerve conduction across the carpal tunnel