Carpal Tunnel Syndrome

Original Editor - Kristin Sartore

Top Contributors - Jaroslaw Pospiech, Kristin Sartore, Admin, Laura Ritchie, Sien Bossant, Lucinda hampton, Kim Jackson, Rachael Lowe, Anas Mohamed, Mathieu Vanderroost, Camille Dewaele, Kai A. Sigel, Sai Kripa, Wanda van Niekerk, Erica Alexander, Chelsea Mclene, Blessed Denzel Vhudzijena and Stuart Wildman  

Search Strategy

First we went looking in the library for useful information in anatomy books and physiotherapy books. Here we found relevant information. To add more scientific information we searched journal articles on the Internet using keywords we found in the library books. We also used some websites. We made sure that the websites we found all had references to journal articles or were written by actual doctors or physiotherapists. Pubmed was a very useful scientific database during our search.
For every individual item, our keyword existed of carpal tunnel syndrome or CTS and the name of the item we were searching information about. We only used articles of which the full text was available.
Which keywords did you use? Give some examples of successful combinations of keywords Epidemiology carpal tunnel syndrome, carpal tunnel syndrome medical, CTS, Carpal tunnel syndrome test,…

Definition/Description

Carpal tunnel syndrome (CTS) is a condition in the wrist. It is caused by compression, traction, pinching, squeezing or irritation of the median nerve, while it runs through the transverse carpal ligament.    1, 2, 3, 4

Clinically Revelant Anatomy

The carpal tunnel (CT) is situated on the palmar side of the wrist. The structures that form the tunnel are the scaphoid, lunate and triquetrium bones and the flexor retinaculum. The three bones form an arch. On top of the arch, running from the pisiform bone and the hamulus of the hamate bone to the scaphoid and the trapezium bone. 2, 4
The eight carpal bones are oriented in two rows between the ulna and radius and the metacarpal bones. These form the c <img src="/images/thumb/d/d3/Interactive_hand_-_carpel_tunnel_-_L16F1.jpg/250px-Interactive_hand_-_carpel_tunnel_-_L16F1.jpg" _fck_mw_filename="Interactive hand - carpel tunnel - L16F1.jpg" _fck_mw_location="right" _fck_mw_width="250" _fck_mw_type="thumb" alt="" class="fck_mw_frame fck_mw_right" /> onnection between the forearm and the hand. The first row exists from lateral to medial of the scaphoid, lunate, triquetrium and pisiform bones. The second row exists from lateral to medial of the trapezium, trapezoid, capitates and hamate bones. The hamate bone has an extra bone called the hamulus. An easy way to recall the orientation of the carpal bones is the sentence: Simply Learn The Parts That The Carpus Has. 4
Through the tunnel run the tendons of the flexor digitorum profundus, flexor digitorum superficialis and flexor pollicis longus muscles and the median nerve. The nerve runs in the middle of the tunnel. [gross] The median nerve runs from the forearm to the palm side of the hand. It controls sensations to the palm side of the thumb and fingers, except for the little finger. It also allows the fingers and thumb to move.3
The CT is very rigid and narrow, so a little swelling of the tendons causes a lot of compression on the median nerve.3
Table 1 4 describes the origin, insertion and function of the three muscles running through the CT. They are all innervated by the median nerve. The flexor digitorum profundus and the flexor pollicis longus muscles are also innervated by the ulnar nerve.

Table 1: Origin, insertion and function of the CT muscles.

Muscles	Origin	Insertion	function
flexor digitorum superficialis	- Medial epicondyle of the humeral head - Ulnar head - Coronoid process - Radial head - Anterior border of the radius	Bodies of the middle phalanx of the second to the fifth finger	- Flexion of the middle and proximal phalanx of the second to the fifth finger - Flexion of the hand
flexor digitorum profundus	- Medial and anterior surface of proximal ¾ of ulna - Interosseous membrane	Anterior base of distal phalanges of the second to the fifth finger	- Flexion of the distal phalanx of the second to the fifth finger - Hand flexion
flexor pollicis longus	- Anterior surface of the radius - Interosseous membrane	Palmar base of distal phalanx of the thumb	- Flexion of the distal phalanx of the thumb

Epidemiology /Etiology

Etiology
Most of the time CTS is idiopathic, so the cause is unknown. This is correlated with hypertrophy of the synovial membrane of the tendons of the flexor muscles. CTS can be related to a degeneration of the connective tissue which? Retinaculum flexorum (Fasc palm, ret. Flex…) with vascular sclerosis, edema and collagen fragments. The most predisposing factors are gender, age, genetic factors and the size of the carpal tunnel. Obesity and smoking are also involved factors. Other predisposing factors are repetitive manual activities, exposure to vibrations and cold temperatures. 6
Secondary CTS can be related to abnormalities of the person with CTS. These abnormalities can be conditions to modify the wall of the tunnel, which causes compression. The shape, position, dislocation or subluxation of the carpal bones can be causal factors. Fractures or skewed consolidation of the distal radius can also be the source of the pain. The last type of cause is wrist arthrosis and inflammatory or infectious arthritis ad synovitis. Secondary CTS can also come from the content of the CT. Inflammatory or metabolic tenosynovitis, tenosynovial hypertrophy, abnormalities of fluid distribution, supernumerary muscles, arterial hypertrophy of the median nerve, intratunnel tumor, hematoma and obesity can all cause the syndrome. 6
Dynamic CTS is usually caused by excessive manual work. Repetitive extension and flexion movements of the wrist combined with flexion of the fingers and supination of the forearm have been mentioned to be the cause. During this motion the pressure in the carpal tunnel increases. 6
Acute CTS is caused by trauma (displacements or fractures), infection, hemorrhage, high-pressure injection, acute thrombosis of the artery and burns. 6
Compression of the medial nerve in the carpal tunnel can be caused by an overuse of the musculus flexor digitorum and superficialis, injury or inflammation diseases, for example [[|]]. 4

Epidemiology
The estimated prevalence of CTS is 4-5% of the population. CTS usually affects people between 40 and 60 years. In 2008 127 269 individuals, aged 20 and older, were operated of CTS in France. These represent an incidence of 1,2/1000, of which 3,6/1000 are female, 1,7/1000 male. 6
There are two peak age frequencies: the first and biggest peak is between 45 and 59 years of which 75% is female. The second age peak is between 75 and 84 years, of which 64% is female. 6

Characteristics/clinical presentation

Because of the irritation to the median nerve, caused by the rigid confines of the carpal tunnel, there are several symptoms detectable in the thumb, the index finger, the middle finger and the lateral half of the ring finger. The carpal tunnel syndrome generally starts with tingling or numbness in the previously mentioned fingers. 7, 8
This sensation often appears while holding an object like a phone or steering wheel. It may increase from your wrist up your arm. The symptoms develop gradually and usually start off being worse at night or early in the morning.8 As the disorder progresses, the feeling of tingling or numbness may become constant and patients may complain of burning pain.8
The final symptoms are weakness and atrophy of the muscles at the base of the thumb.7 8
The consequences for the functions of the neural tissue are loss of sensory feedback, which causes clumsiness and weaknees, and loss of motor power.8

Differential Diagnosis

The differential diagnosis is complex because the diagnostic criteria of the carpal tunnel syndrome are quite subjective. 10
The neurological symptoms may be caused by another nerve. In this case you need to take different pathologies in account. For example: a pinching of the nn. digitales in the palm of your hand, a pinching of the median nerve at the level of the elbow or cervicobrachial syndrome as result of a pinched nerve root. A major cause of this last pathology is a hernia nuclei pulposa. Even though the neurological symptoms of this pathology have a more segmental character, the C7-C8-radiculopathy is very similar to the carpal tunnel syndrome. This is because there are also sensibility disorders in the median and ulnar area of the hand. The force of the m. abductor pollicis longus is normally maintained. Another pathology is neuralgic amyotrophy. The symptoms start with pain in the area of the shoulder or the upper arm and sometimes neurological symptoms in the hand. 10

There are intracranial neoplasms. Sometimes they present tingling, weakness or loss of coordination in the hand. The pattern of weakness of hypoesthesia will not be in a distribution limited to that of the median nerve.10

A second pathology is multiple sclerosis, which can superficially be similar to the symptoms of the carpal tunnel syndrome. With the use of a neurological evaluation, it can be distinguished. There will be a reaction in multiple areas that are not typical for the carpal tunnel syndrome.10

The third one, cervical radiculopathy, is the most common neurological condition which can be confused or which can coexist with the carpal tunnel syndrome. In this case there will be weakness or numbness in proximal dermatomes, which do not compare to the symptoms of the carpal tunnel syndrome.

Cervical syringomyelia shows symptoms like weakness and numbness. The origin of the symptoms is located in the cervical spine.

The [[|]] can also be confused with the carpal tunnel syndrome.
The thoracic outlet syndrome has symptoms in the ulnar nerve distribution.
A pancoast tumor has symptoms, which may present in the hand but the neurological distribution will be rather different. 10
Other pathologies are: posttraumatic dystrophy, CVA, ulnar neuropathy, radial neuropathy, churg-strauss syndrome, arthritis and median nerve contusion. 10

Diagnostic procedures

A second type of test is the electroneuromyography (ENMG) examination. 7
By using a stimulation-detection stage it is possible to examine the sensory and motor nerve conductance of the median nerve. It also highlights the elective weakening in passing through the carpal tunnel. It is considered abnormal when there is a diminished sensory conduction velocity between the wrist, the palm of the hand and the fingers. This test may be used to diagnose the condition and rule out other pathologies.6
Another test is the electromyogram (EMG) of the muscles innervated by the median nerve. It measures electrical dischargers produced in the muscles. The electrical activity of the muscles will be evaluated when they contract and when they are at rest. This test can determine if there is any muscle damage and can rule out other conditions. 12, 13
A last test is ultrasound. It can identify space-occupying lesion in and around the median nerve. The test can confirm abnormalities that can diagnose CTS and help guide steroid into the carpal tunnel.7 14
Sometimes an X-ray is recommended to exclude other causes of wrist pain like arthritis or a fracture.6

Outcome Measures

Outcome Measures Symptom Severity Scale is a self-administered questionnarie for the assessment of severity of symptoms and functional status in paitents who have carpal tunnel syndrome.  A study by Levine et al demonstrated that the instrument is reproducible, internally consistent, valid, and responsive to clinical change.

<a href="DASH Outcome Measure">DASH</a> - The disabilities of the arm, shoulder and hand (DASH) questionnaire is a self-administered region-specific outcome instrument developed as a measure of self-rated upper-extremity disability and symptoms. The DASH consists mainly of a 30-item disability/symptom scale, scored 0 (no disability) to 100.  The DASH can detect and differentiate small and large changes in disability over time after surgery in patients with upper extremity musculoskeletal disorders.

Medical Management

Non-Surgical management

<img src="/images/thumb/f/fc/Carpal_tunnel_splint.jpg/200px-Carpal_tunnel_splint.jpg" _fck_mw_filename="Carpal tunnel splint.jpg" _fck_mw_location="right" _fck_mw_width="200" alt="" class="fck_mw_right" />

Non-surgical managment includes use of splints, activity modification, patient education, diuretics, and NSAIDs.  A number of nonsurgical interventions benefit CTS in the short term, but there is sparse evidence on the midterm and long-term effectiveness of these interventions.

Surgical Management

<img src="/images/thumb/b/b1/Carpal_Tunnel_Syndrome_Operation.jpg/200px-Carpal_Tunnel_Syndrome_Operation.jpg" _fck_mw_filename="Carpal Tunnel Syndrome Operation.jpg" _fck_mw_location="right" _fck_mw_width="200" alt="" class="fck_mw_right" />

Surgical treatment seems to be more effective than splinting or anti-inflammatory drugs plus hand therapy in the midterm and long term to treat CTS<span class="fck_mw_ref" _fck_mw_customtag="true" _fck_mw_tagname="ref" name="Bionka" />. However, there is no unequivocal evidence that suggests one surgical treatment is more effective than the other<span class="fck_mw_ref" _fck_mw_customtag="true" _fck_mw_tagname="ref" name="Bionka" />.

Differential Diagnosis

Differential diagnosis for CTS includes <a href="Cervical Radiculopathy">cervical radiculopathy</a>, thoracic outlet syndrome, <a href="Pronator Teres Syndrome Test">pronator syndrome</a>, <a href="Wrist and Hand Osteoarthritis">wrist joint arthritis</a>, tendonitis, and fibrositis.<span class="fck_mw_ref" _fck_mw_customtag="true" _fck_mw_tagname="ref" name="Dutton" />

Key Evidence

Bionka M. Huisstede, Peter Hoogvliet, Manon S. Randsdorp, Suzanne Glerum, Marienke van Middelkoop and Bart W. Koes. <a href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WB6-50DR27B-5&_user=10&_coverDate=07%2F31%2F2010&_rdoc=5&_fmt=high&_orig=browse&_srch=doc-info%28%23toc%236702%232010%23999089992%232189767%23FLA%23display%23Volume%29&_cdi=6702&_sort=d&_docanchor=&_ct=32&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=3b12eaad950b04fab8ae43482bf07edd">Carpal tunnel syndrome. Part I: effectiveness of nonsurgical treatments – a systematic review.</a> Arch Phys Med Rehabil. 2010 Jul;91(7):981-1004.

Bionka M. Huisstede, Manon S. Randsdorp, J. Henk Coert, Suzanne Glerum, Marienke van Middelkoop and Bart W. Koes. <a href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WB6-50DR27B-6&_user=10&_coverDate=07%2F31%2F2010&_rdoc=6&_fmt=high&_orig=browse&_srch=doc-info%28%23toc%236702%232010%23999089992%232189767%23FLA%23display%23Volume%29&_cdi=6702&_sort=d&_docanchor=&_ct=32&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=a1270c6bc817ee1cba09888530bedc0b">Carpal tunnel syndrome. Part II: effectiveness of surgical treatments–a systematic review.</a> Arch Phys Med Rehabil. 2010 Jul;91(7):1005-24.

Resources 

Dutton, M. Orthopaedic examination, evaluation, and intervention. New York: McGraw Hill; 2004.

Flynn TW, Cleland JA, Whitman JM. Users' guide to the musculoskeletal examination. Fundamentals for the evidence-based clinician. United States:Evidence in Motion; 2008.

Case Studies

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Carpal Tunnel Syndrome case study with MSK Ultrasound and US guided injection can be seen here http://theultrasoundsite.co.uk/carpal-tunnel-syndrome/

Recent Related Research (from <a href="http://www.ncbi.nlm.nih.gov/pubmed/">Pubmed</a>)

http://www.ncbi.nlm.nih.gov/entrez/eutils/erss.cgi?rss_guid=1VePQbT36PByW9UeoZTRookH3hVMrxN0QI2FuBloyMUTmNx9UI%7Ccharset=UTF-8%7Cshort%7Cmax=10

References

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