Prepared by: medicine students in King AbdulAziz University.

Carpal Tunnel Syndrome

Sara is 33 years old female patient. She was

brought to the OPD clinic complaining of

right hand numbness/pain of 6 months duration.

The patient’s symptoms started during her last

pregnancy where the numbness was severe

enough to wake her up from sleep. She used to shake and rub her hand to improve the symptoms. She was advised to wear a wrist splint during her pregnancy and to see a doctor 3 months following delivery if her symptoms persisted.

On examination the patient described numbness involving her thumb, index and middle finger.

Her motor examination of the hand muscles was normal. There was no evidence of cervical spine disease. Her blood results of the thyroid hormone were within normal range.

Case study:

Objectives

• At the end of the presentation , the student must be able to:

1. List the differential diagnosis of hand numbness/pain.

2. Describe the detailed anatomy of the carpal tunnel.

• At the end of the presentation , the student should be able to:

1. Describe the pathophysiology of carpal tunnel syndrome.

2. List with explanation, the treatment options of carpal tunnel syndrome.

1st Objective

• List the differential diagnosis of hand numbness/pain.

Numbness of hands is usually caused by irritation or compression of branch of a nerve traveling to the hands or fingers.

Symptoms may accompany numbness:

1- tingling 3- weakness

2- burning 4- sharp pain

Differential diagnosis of hand

Numbness and pain:

¤Carpal tunnel syndrome (most common)

¤Cervical disc disease*.

¤De Quervain’s tenosynovitis*.

¤Reynaud's diseases*.

*Check the notes below

2nd Objective

Describe the detailed anatomy of the carpal tunnel

1-How carpal

tunnel is formed?2-Boundries

3-What passes

inside and outside?

1-How the carpal tunnel is formed?

A-arch B- flexor retinaculum

1-How is the carpal tunnel (C.T.) formed?

¤The anterior concave surface of the carpus is transformed into tunnel by the attachment of the flexor retinaculum.

¤It is the passageway on the palmer side of the wrist that connects the forearm to the palm of the hand.

A-arch

• The arch is formed of 8 carpal bones , made up of two rows of 4 bones.

• The proximal row consist of (L:M) the scaphoid , lunate , triquetrum , and pisiform bones.

• The distal row consist of (L:M) the trapezium , trapezoid , capitate , and hamate bones.

Due to weak blood supply of the scaphoid bone, it has a bad healing (takes long time)

B- flexor retinaculum

• It is a thickening of deep fascia, which keep the tendons of flexor muscles.

• It stretches across the front of the wrist and converts the concave anterior surface of the hand into the carpal tunnel.

2-boundries¤ Dorsally ( posterior) :

Carpal bones.

¤ Palmary ( anterior) :

Thick flexor retinaculum .

¤ Radial margin (lateral):

The scaphoid, trapezium.

¤ Ulnar margin (medial ) :

The hook of the hamate, triquetrum and

pisiform .

A-Structures passing superficial to

flexor retinaculum (outside the

tunnel) (Median to Lateral)

¤ Ulnar nerve

¤ Ulanr artery

¤ Palmar cutaneous branch of ulnar nerve

¤ Tendon of Palmaris longus

¤ Palmar cutaneous branch of median nerve

B-Structures passing deep to the flexor

retinaculum medial to lateral (content of carpal

tunnel(:

flexor tendons (not the muscles themselves) pass through the carpal tunnel:

1-(F.D.S.) flexor digitorum superficialis (four tendons)

2-(F.D.P.) flexor digitorum profundus (four tendons)

3-(F.P.L.) flexor pollicis longus (one tendon)

¤A single nerve passes through the tunnel: the median nerve .

Flexor carpai radialis passes through a split made of flexor retinaculum

(NOT one of the contents of the carpal tunnel)

Median nerve

•It originate from lateral and medial cord of brachial plexus (C5,6,7,8 and T1).

•It ends in the hand by passing through the carpal tunnel.

Motor and sensory supply of median nerve

*Motor supply:(5 muscles)

A-thener group: - abductor pollicis brevis

- flexor pollicis brevis

- opponens pollicis

B-1st,2nd lumberical ms.

*Sensory supply:

3.5 lateral palmer digits(thumb , index, middle and half of the ring)

Important points!• The (C.T.) is formed of

• The radius is attached to

• The only nerve passes in C.T. is

• Median nerve supplies

• Other structures passes in (C.T.)

8 carpal bones covered by flexor retinaculum.

scaphoid(commonly fractured!) and lunate bones.

median nerve..

(5 muscles.)and(3.5 L.P.D.).

are Tendons of F.D.S/F.D.P/F.P.L.

3rd Objective

• Describe the pathophysiology of carpal tunnel syndrome.

What is carpal tunnel syndrome ?

It is a painful condition brought by increased pressure on the median nerve that

supplies function and feeling to the thumb, index, middle and one-half of the ring finger.

Causes of carpal tunnel syndrome

The most common cause of carpal tunnel syndrome is

idiopathic (which means that the exact aetiology is

unknown).

• In general, anything that crowds, irritates or compresses the median nerve in the carpal tunnel space can lead to carpal tunnel syndrome.

Risk factors of carpal tunnel syndrome*

1-Alterations in the balance of body fluids. Certain conditions such as pregnancy, obesity, thyroid hormone disorders and kidney failure, can affect the level of fluids in your body.

Fluid retention common during pregnancy, for example may increase the pressure within your carpal tunnel, irritating the median nerve.

Carpal tunnel syndrome associated with pregnancy generally resolves on its own after the pregnancy is over.

Q:Why can pregnancy aggravate the symptoms of carpal tunnel syndrome?

A: Pregnancy can aggravate the symptoms of CTS due to weight increase, fluid retention and hormonal changes.

2-Nerve-damaging conditions. Some chronic illnesses, such as diabetes and alcoholism, increase your risk of nerve damage, including damage to your median nerve.

3-Inflammatory conditions. inflammation, such as rheumatoid arthritis or an infection, can affect the tendons in your wrist, exerting pressure on your median nerve.

4-Anatomic factors. A wrist fracture or dislocation that alters the space within the carpal tunnel can create extraneous

pressure on the median nerve.

Symptoms of carpal tunnel syndrome

• Hand numbness over lateral 3 & half fingers(symptom)

• Paresthesia (pins and needles) feeling (symptom)

• Swelling (sign)

•Weak pinch grip(symptom)

•Muscle atrophy of the thenar (muscle wasting) (sign)

atrophy of the thenar muscle

Symptoms of carpal tunnel syndrome

Q: The symptoms can be noticed during daily activities like driving or reading the newspaper but many people complain of numbness that wakes them in the middle of the night (why?)

The reason that symptoms are worse at night may be related to:

• The flexed-wrist sleeping position (because flexion of the wrist will decrease the size of the tunnel)

• Fluid accumulating around the wrist and hand while lying flat (congestion of veins)

• Breathing is decreased while sleeping which will increase CO2

in blood causing vasodilatation of blood vessels.

• Sleeping on the hand itself will cause a decrease in the size of the tunnel.

Cont’d

Pathophysiology of Carpal Tunnel Syndrome

• The median nerve can be compressed by :

increase in the size of the contents

(e.g. by swelling or inflammation of the tendons)

or

decrease in the size of the tunnel

(e.g., wrist fracture…etc)

Pathophysiology of Carpal Tunnel Syndrome

• Certain jobs, such as assembly line workers, carpenters, and hairstylists, may have a higher risk associated with developing carpal tunnel syndrome. Any activity requiring prolonged repetitive use of the arms, wrists, and hands have a significant increased incidence of the developing symptoms.

4th Objective

• List with explanation, the treatment options of carpal tunnel syndrome.

The goal of treatment for carpal tunnel syndrome is

to allow you to return to your normal function and

activities and to:

• Determine the causes of your carpal tunnel symptoms, you can then identify whether there are activities for you to avoid or ways you can help prevent the condition.

• Reduce any inflammation of tissues in the wrist that puts pressure on the median nerve.

• Prevent nerve damage and loss of muscle strength in your fingers and hand.

Treatment of carpal tunnel syndrome include:

•Nonsurgical treatment

• Surgical treatment

•Changing or avoiding activities that may be causing symptoms, and taking frequent breaks from repetitive tasks.

•Wearing a wrist splint to keep your wrist straight, usually just at night.

Nonsurgical treatment options :

If the symptoms are not severe, nonsurgical treatment are used:

•Using non-steroidal anti-inflammatory drugs (NSAIDs) to relieve pain and reduce inflammation.

•Using corticosteroid injections into the carpal tunnel may be considered if other methods to reduce inflammation do not work (very effective method).

Surgical treatment options:

Carpal tunnel release surgery:

is used to relieve severesymptoms of carpal tunnel syndrome, which causes pain or weakness in the hand and fingers.It involves cutting a ligament in

the wrist(transverse ligament) to relieve pressure on the median nerve.

• Surgery is usually successful. In some cases it does not completely relieve the numbness and pain in the fingers or hand. This may be the case if there has been permanent nerve damage caused by long-standing carpal tunnel syndrome or by other health problems such as diabetes.

• Endoscopic Carpal Tunnel Surgery for Carpal Tunnel Syndrome:

Endoscopic surgery uses tube with a camera attached (endoscope).

The endoscope lets the doctor see and cut structures in the wrist, such as the transverse carpal ligament, without opening the entire area with a large incision !

Surgical treatment options:

Endoscopic surgery Carpal tunnel release surgery

Clinical Anatomy by Systems. Richard S. Snell. 1st Edition, (2007) Lippincott Williams & Wilkins. Chapter 11 (PP 334-335), Chapter 13 (PP 471), Chapter 17 (PP 621, 623).

http://www.assh.org/Public/HandConditions/Pages/Hand.aspx http://www.repetitive-strain.com/ctsindex.html. http://www.selfcare4rsi.com/carpal-tunnel-syndrome-anatomy.html. http://www.carpal-tunnel-symptoms.com/anatomy-of-the-carpal-tunnel.html

References:

Thank you very much

• Prepared by: medicine students in King AbdulAziz University.