Carpal Tunnel Syndrome

Question 1

What is CTS?

Answer 1

Compression of the median nerve within the carpal tunnel of the wrist.

This is due to a raised pressure within the compartment.

This compression leads to pain, numbness and paraesthesia in lateral 3 1/2 digits.

Question 2

Epidemiology of CTS

Answer 2

Accounts for 90% of nerve compressions

F > M

Peak incidence around 45-60 yo.

Question 3

Risk Factors

Answer 3

Female gender

Increasing age

Pregnancy

Obesity

Previous injury to wrist/Repetitive hand or wrist movement

DM

RA

Hypothyroidism

Question 4

Clinical features

Answer 4

Pain, numbness and/or paraesthesia in median nerve sensory distribution.

Palm is often spared (palmar cutaneous branch branches proximal to flexor retinaculum and passes over CT)

Symptoms are worst at night and relieved by temporarily hanging affected arm over side of bed or shaking back and forth.

Question 5

Examinations findings

Answer 5

Early
No visible findings

Late
Weakness of thumb abduction due to denervation atrophy of thenar muscles

Wasting of the thenar eminence

Question 6

Special tests for CTS

Answer 6

Tinel’s test (percussing over median nerve)

Phalen’s test (holding wrist in full flexion for one minute)

Question 7

Dx

Answer 7

Cervical radiculopathy of C6 (usually neck pain too and entire arm length)

Pronator teres syndrome

Flexor carpi radilais tenosynovitis (tenderness at base of thumb)

Question 8

How does pronator teres syndrome differ?

Answer 8

It is median nerve compression by Pronator teres but proximal.

So symptoms will be in proximal forearm and sensation over palm will also be reduced.

Question 9

Ix

Answer 9

Clinical diagnosis

Uncertain cases nerve conduction studies can be done. (Normal does not rule out CTS however)

Question 10

Conservative treatment of CTS

Answer 10

• *Wrist splint** (mainly at night) which prevents flexion and holds wrist in place.
• *Physiotherapy**

Corticosteroid injections can be trialled

NSAIDs (limited support)

Question 11

Indications for surgical treatment

Answer 11

Only in severely limiting cases where previous treatments have failed

Question 12

Surgical treatment for CTS

Answer 12

Carpal tunnel release surgery

This decompresses the carpal tunnel by cutting through flexor retinaculum

Leads to reduced pressure on median nerve.

It is performed under local anaesthetics and is a day case.

Question 13

Complications of carpal tunnel surgery.

Answer 13

Persistent CTS symptoms

Infection

Scar formation

Nerve damage

Trigger thumb

Outocme is good however (90%)

Question 14

Complications of CTS

Answer 14

Long-term untreated CTS can lead to neurological impairment that can not be dealt with by surgery.