Anatomy of carpal tunnel

Anatomy of the carpal tunnel
- transverse carpal ligament, is a heavy band of fibers which runs between hamate & pisiform medially to scaphoid and trapezium laterally,and forms fibrous sheath which contains carpal tunnel anteriorly within fibro-osseous tunnel;
- posteriorly, tunnel is bordered by carpal bones, and transports median nerve & finger flexor tendons from forearm to hand;
- lies deep to palmaris longus & is defined by 4 bony prominences;
- proximally, by pisiform & tubercle of scaphoid;
- distally by hook of hamate & tubercle of trapezium;
-from hamate & pisiform medially to scaphoid & trapezium laterally;
- transverse carpal ligament, portion of volar carpal ligament, runs between these 4 prominences & forms fibrous sheath which contains carpal tunnel anteriorly w/in fibro-osseous tunnel;
- posteriorly tunnel is bordered by carpal bones;




Contents of Tunnel:
- tunnel transports median nerve & finger flexor tendons (FDS, FDP , & FPL);
- motor branch of median nerve in hand arises under or just distal to flexor retinaculum, & winds around distal border of retinaculum to reach hypothenar muscles
and the lateral 2 lumbricals;
- numerous variations in the branching have been described;
- sensory branches innervate lateral three and 1/2 digits & palm of the hand;

- Guyon's Canal
- ulnar nerve & artery do not pass thru tunnel but lie superficial to it in guyon's canal
- pisiform is palpable & serves to mark entry, on its lateral aspect, of ulnar nerve and artery into the hand;

- Landmarks:
- distal volar flexion crease crosses proximal end of the scaphoid & pisiform & identifies proximal edge of the transverse carpal ligament;
- pisiform is palpable and just laterally will identify entry of ulnar nerve and artery into hand;
- all thenar & hypothenar muscles, except the abductor minimi, originate partly from the transverse carpal ligament.


- Kaplan's Line:
- Kaplan oblique line (line drawn from apex of interdigital fold between thumb and index
finger, toward ulnar side of hand, parallel w/ proximal palmar crease, & passing
4-5 mm distal to pisiform bone;

Carpal Tunnel Syndrome Mind Maps

Mind maps for carpal tunnel syndrome.

This one includes causation, population at risk, symptoms & diagnosis/investigation methods.


This one is for treatment options.


The maps are rather large, because I crammed everything from MayoClinic into it. Me summarizing is like trying to put out a fire with gasoline.

Median Trap - CTS Causation

MEDIAN TRAP
Myxedema
Edema
Diabetes
Idiopathic
Acromegaly
Neoplasm
Trauma
Rheumatoid arthritis
Amyloidosis
Pregnancy

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Myxedema
Terminology:
myx(o)-:

• mucus; slime. [Greek]

edema:

• an abnormal accumulation of fluid in intercellular spaces of the body.

pitting edema:

• that in which pressure leaves a persistent depression in the tissues.

mucin:

• any of a group of protein containing glycoconjugates wth high sialic acid or sulfated polysaccharide content that compose the chief constituent of mucus.

-osis:

• disease; morbid state; abnormal increase. [Greek]

mucinosis:

• a state with abnormal deposits of mucins in the skin.

Definition:
A dry, waxy type of swelling (nonpitting edema) with abnormal deposits of mucin in the skin (mucinosis) & other tissues, associated with hypothyroidism; the facial changes are distinctive, with swollen lips & thickened nose.

Association with Carpal Tunnel Syndrome:
While studies have displayed a strong, positive association between hypothyrodism (hence myxedema) and carpal tunnel syndrome, the mechanisms of this association remains unclear.

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Edema
Definition:
An abnormal accumulation of fluid in intercellular spaces of the body.

Association with Carpal Tunnel Syndrome:
Accumulation of fluid within the carpal tunnel may exert pressure on the median nerve, cause carpal tunnel syndrome.

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Diabetes
Definition:
Any disorder characterized by excessive urine excretion.

Used alone, often refers to diabetes mellitus - a chronic syndrome of impaired carbohydrate, protein, & fat metabolism owing to insufficient secretion of insulin or to target tissue insulin resistance.

Association with Carpal Tunnel Syndrome:
Hyperglycaemia, characteristic of diabetes mellitus, can damage the blood vessels that supply the nerves & the nerve coverings, causing diabetic neuropathy with symptoms of numbness, pain & weakness on the affected limb (peripheral neuropathy is the most common form of diabetic neuropathy).

If the median nerve is damaged, carpal tunnel syndrome may result.

~*~
Idiopathic
Terminology:
idi(o)-:

• self; peculiar to a substance or organism. [Greek]

-pathy:

• morbid condition or disease; generally used to designate a noninflammatory condition. [Greek]

Definition:
Self originated; occurring without known cause.

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Acromegaly
Terminology:
acr(o)-:

• extreme; top; extremity. [Greek]

-megaly:

• enlargement. [Greek]

Definition:
Abnormal enlargement of limbs, caused by hypersecretion of growth hormones after maturity.

Association with Carpal Tunnel Syndrome:
Acromegaly is a rare disease in which high levels of growth hormone lead to increases in the sizes of the hands, feet, and head, as well as changes in internal organs and the skin.

It is not clear whether acromegaly leads to the carpal tunnel syndrome because the soft tissues in the carpal tunnel swell & compresses the median nerve, or because the nerve itself swells - although studies have shown that it would appear to be the latter that is causing the syndrome.

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Neoplasm
Terminology:
ne(o)-:

• new; recent. [Greek]

plasm:

• plasma; formative substance (cytoplasm, hyaloplasm, etc.)

hyal(o)-:

• glassy. [Greek]

hyaloplasm:

• the more gluid, finely granular substance of the cytoplasm of a cell.

Definition:
Tumor; ay new and abnormal growth, specifically one in which cell multiplication is uncontrolled & progressive; may be benign or malignant.

Association with Carpal Tunnel Syndrome:
A tumor growth about the carpal tunnel may reduce the carpal tunnel space, effectively producing a compressing force on the median nerve. (e.g. carpal bone neoplasms)

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Trauma
Definition:
Injury; psychological or emotional damage.

Association with Carpal Tunnel Syndrome:
Acute carpal tunnel syndrome may develop following a major trauma to the upper extremity (typically a distal radius fracture), a carpal dislocation, or a crush injury where the median nerve is compressed by the loose bodies in the carpal tunnel.

Malunion post-fracture may also result in the median nerve being compressed by the inappropriately fused bones that may reduce the carpal tunnel space.

Wear & tear of the wrist joint associated with repeated use or repetitive motion may be related to carpal tunnel syndrome. However, opinions still remain divided on this subject.

~*~
Rheumatoid Arthritis
Terminology:
rheumatism:

• any of a variety of disorders marked by inflammation, degeneration, or metabolic derangement of the connective tissue structures, especially the joints & related structures, and attended by pain, stiffness, or limitation of motion.

arthritis:

• inflammation of a joint.

-osis:

• disease; morbid state; abnormal increase. [Greek]

ankyl(o)-:

• bent; crooked; in the form of a loop; adhesion. [Greek]

ankylosis:

• immobility and consolidation of a joint due to disease, injury, or surgical procedure.

Definition:
A chronic systemic disease primarily of the joints, usually polyarticular, marked by inflammatory changes in the synovial membranes & articular structures & by atrophy & rarefaction of the bones.

In late stages, deformity & ankylosis develop.

Association with Carpal Tunnel Syndrome:
Rheumatoid arthritis is most characterized by joint damage; however it is really a systemic disease that affects the whole body.

Damage to the musculoskeletal structures surrounding the joints may cause the bones & tendons to become deformed, especially those of the hands & feet. Nerve entrapment is a common result of these deformities - entrapment of the median nerve would thus be a possible complication, leading to carpal tunnel syndrome.

~*~
Amyloidosis
Terminology:
amyl(o)-:

• starch. [Greek]

-oid:

• resembling. [Greek]

-osis:

• disease; morbid state; abnormal increase. [Greek]

amyloid:

• starchlike; amylaceous; the pathologic, extracellular, waxy, amorphous substance deposited in amyloidosis, being composed of fibrils in bundles or in a meshwork of polypeptide chains.

• a pathologic proteinaceous substance, deposited between cells in various tissues & organs of the body in a wide variety of clinical settings.

Definition:
A group of conditions caused by accumulation of amyloid in organs & tissues, which compromises their function.

Associated disease states may be inflammatory, hereditary, or neoplastic.

Deposition may be local, generalized, or systemic.

Association with Carpal Tunnel Syndrome:
Amyloidosis results from abnormal folding of proteins, which are deposited as fibrils in extracellular tissues & disrupt normal function. Misfolded proteins are often unstable & self-associated, ultimately leading to the formation of oligomers & fibers that are deposited in tissues.

Accumulation of such insoluble protein deposits in the affected organs can cause stiffness & decreased functionality, precipitating carpal tunnel syndrome if the wrist is affected.

~*~
Pregnancy
Definition:
The condition of having a developing embryo or fetus in the body, after the union of an ocyte and spermatozoon.

Association with Carpal Tunnel Syndrome:
Swelling is common during pregnancy, especially in the third trimester, as the mother's body will produce approximately 50% more blood & fluids to accommodate the growing baby. Hormone fluctuations may also contribute to edema about the extremities.

Water retention during pregnancy helps maintains the mother's body flexible, to allow room for expansion during pregnancy. The extra fluid contained in the tissues & muscles of the body helps the joints prepare for labor & delivery.

Excessive swelling about the wrist area may lead to the undesired compression of the median nerve, precipitating carpal tunnel syndrome-like symptoms; though the symptoms generally wear off once the swelling subsides.

Treatment and management for carpal tunnel syndrome

The goal of treatment for CTS is to reduce the swelling and pressure on the median nerve. Fortunately for most people who develop carpal tunnel syndrome, proper treatment usually can relieve pain, numbness and tingling, and restore normal function of the wrist and hand. Treatment may include the use of splints or braces, anti-inflammatory medications, cortisone injections or surgery.

the medical team determines treatments based on:
-the severity of the condition
-history of previous treatments for the condition
-overall health and the demands of occupation/daily activities
-the patient's preference

In the earliest stages, the numbness and tingling can be relieved simply by shaking the hand, which eases the pressure on the median nerve. If symptoms persist and worsen, getting rid of the numbness and tingling becomes increasingly difficult.

Waking up in the night with numbness and tingling is common, since sleep positions often hyperextend or hyperflex the wrist, pinching the median nerve.

Special physical therapy exercises, heat treatments and massage may alleviate some discomfort, along with avoiding the movements or strain on the wrist that provoke the symptoms.

If symptoms persist, more aggressive treatments are available. Most patients, but not all, improve following treatment.

Four treatment strategies are used, depending on the severity of the condition: A splint or brace; nonsteroidal, anti-inflammatory drugs; cortisone injections; and surgery (open incision or endoscopic).

Splint or Brace
In the early stages of CTS, a night splint is the first treatment recommended. This splint keeps the wrist in a neutral position (not bent back too far nor down too far) during sleep, minimizing pressure on the median nerve and relieving the nighttime symptoms of tingling and numbness. The splint can also be effectively used during the day. Using a splint can make CTS symptoms disappear in some patients.

Splinting the wrist at a neutral angle helps to decrease repetitive flexion and rotation, thereby relieving mild soft tissue swelling or tenosynovitis. Splinting is probably most effective when it is applied within three months of the onset of symptoms.

The optimal splinting regimen depends on the patient's symptoms and preferences. Nightly splint use is recommended to prevent prolonged wrist flexion or extension. When worn at night for four weeks, a specially designed wrist brace was found to be more effective than no treatment in relieving the symptoms of carpal tunnel syndrome.

Some patients choose to wear a wrist splint all of the time. Compared with nighttime-only splint use, full-time use has been shown to provide greater improvement of symptoms and electrophysiologic measures; however, compliance with full-time use is more difficult.


Manu hand brace for the conservative treatment of carpal tunnel syndrome (palmar and dorsal views). This specially designed brace provides gentle pressure to the heads of the metacarpal bones while stretching the third and fourth fingers.




Nonsteroidal Anti-inflammatory Drugs
Diuretics, nonsteroidal anti-inflammatory drugs (NSAIDs), pyridoxine (vitamin B6), and orally administered corticosteroids have been used with varying degrees of success in patients with carpal tunnel syndrome.
Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDS) may help relieve pain caused by swelling of the carpal tendons. They may be most effective when used in combination with other nonsurgical treatments; which makes it difficult to know how much the NSAIDS are adding to the known benefits of the other treatments.

If inflammation is not the cause of a patient's pain, NSAIDS are unlikely to help. They also won't help with other symptoms such as tingling, numbness or weakness. The potential side effects of taking NSAIDS over a long period of time must also be weighed.

Orally administered corticosteroids have been shown to be more effective than NSAIDs or diuretics in the short-term treatment of carpal tunnel syndrome.

Cortisone Injections
Injecting the affected area with a steroid drug such as cortisone may provide some relief from symptoms. This treatment may be useful in pregnancy-related carpal tunnel syndrome or in cases where using a splint and nonsteroidal, anti-inflammatory drugs have failed to relieve the symptoms. Relief can last up to six months and sometimes longer. If symptoms recur, injections can be repeated, but not more than once every six weeks.

The injected steroid drug spreads around the swollen membranes and surrounding tendons and shrinks them, relieving the pressure on the median nerve. The cortisone amount is small and when used this way, usually has no harmful side effects.

Combined injection of a corticosteroid and a local anesthetic into or proximal to the carpal tunnel can be used in patients with mild to moderate carpal tunnel syndrome. Such injections can be diagnostic as well as therapeutic.


Method of injecting directly into the carpal tunnel.Injection occurs along the right side of the palmaris longus tendon, which can be identified by having the patient pinch the thumb and fifth fingers together while slightly flexing the wrist. If the palmaris longus tendon cannot be identified, the needle is inserted slightly ulnar to the midline. The needle is angled downward at a 45-degree angle toward the tip of the middle finger and advanced 1 to 2 cm as it traverses the flexor retinaculum. Discomfort in the fingers should prompt repositioning of the needle.



Method of injecting proximal to the carpal tunnel.Injection occurs at the distal wrist crease between the tendons of the palmaris longus and flexor carpi radialis muscles. The mixture is introduced as a bolus and massaged toward the carpal tunnel. The needle should be advanced slowly and repositioned if resistance is encountered or the patient reports pain or paresthesias in the fingers.

Direct injection into the carpal tunnel by either method carries the potential for needle injury to the median nerve, intratendinous injection and tendon rupture, or dysesthesias (secondary to intrafascicular injection) that may persist for months. An alternative approach is to place the injection proximal to the carpal tunnel, rather than directly in it. This approach lowers the risk of damage to the median nerve and theoretically treats concomitant swelling at the volar side of the forearm. With any method, injection of corticosteroid into the median nerve must be avoided.

Splinting is generally recommended after local corticosteroid injection.If the first injection is successful, a repeat injection can be considered after a few months. Surgery should be considered if a patient needs more than two injections.

Iontophresis is a newer way to get cortisone medications into the carpal tunnel. An electrical current is used to move the molecules of the medication through the skin into the carpal tunnel. The technique is less painful than an injection, but may not be as effective in some people.

Surgery
Surgery should be considered in patients with symptoms that do not respond to conservative measures and in patients with severe nerve entrapment as evidenced by nerve conduction studies, thenar atrophy, or motor weakness.

Surgery/Carpal tunnel release surgery (Open Incision or Endoscopic)
Carpal tunnel surgery "releases" pressure on median nerve.
Surgery to relieve CTS is called carpal tunnel release. It involves cutting the ligament that forms the roof of the carpal tunnel to relieve the pressure on the median nerve. It may be performed as an endoscopic or as an open procedure.Surgeons in orthopedic surgery, plastic surgery and neurosurgery may be involved.

Carpal tunnel release surgery is an outpatient procedure that is performed using regional anesthesia. The traditional surgical approach uses a long palmar curvilinear incision to facilitate division of the transverse carpal ligament and its overlying structures.







Endoscopic (Minimally Invasive) Surgery
At times, surgery can be done with an endoscope, a device with a tiny television camera attached to it that allows the surgeon to see inside the carpal tunnel and perform the surgery through small incisions in the hand or wrist. The endoscopic method is more technically demanding and it is important to select a medical center experienced in this technique.

Endoscopic carpal tunnel release is a newer procedure that allows division of the transverse carpal ligament with the overlying structures left intact. Use of this procedure purportedly lessens scar formation and allows an earlier return to work and activities of daily living. The wrist is generally splinted for three to four weeks after surgery.






Open Incision
In open surgery, the surgeon makes an incision in the wrist over the carpal tunnel and releases the nerve.

An open and endoscopic procedures are done under local anesthesia, and patients usually go home soon after surgery. In most cases, surgery results in significant improvement in symptoms, but some residual numbness, pain or weakness may persist.




Ultrasound therapy
Ultrasound therapy may be beneficial in the longer term management of carpal tunnel syndrome. More studies are needed to confirm the usefulness of ultrasound therapy for carpal tunnel syndrome.

Following Surgery
Following surgery, most surgeons permit light use of the hand and wrist within a few days. Unrestricted use may take from several weeks to as long as a few months.

If surgery appears to be the best alternative for relieving symptoms or preventing further muscle atrophy, the patient and surgeon should discuss the procedure that will work best.


Management/Prevention
Mild symptoms usually can be treated with home care. The sooner the treatment, the better your chances of stopping symptoms and preventing long-term damage to the nerve.

You can do a few things at home to help your hand and wrist feel better:
-Stop activities that cause numbness and pain. Rest your wrist longer between activities.
-Ice your wrist for 10 to 15 minutes 1 or 2 times an hour. Try taking nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and reduce swelling.
-Wear a wrist splint at night to keep your wrist in a neutral position. This takes pressure off your median nerve. Your wrist is in a neutral position when it is straight or only slightly bent. Holding a glass of water is an example of your wrist in a neutral position.

See your doctor if your symptoms do not get better after 1 to 2 weeks of home care, or if you have had bad symptoms from the start. You may need medicine for carpal tunnel syndrome or for a health problem that made you likely to get carpal tunnel syndrome.

Surgery is an option. But it's usually used only when symptoms are so bad that you can't work or do other things even after 3 to 12 months of other treatment.

During surgery, the doctor cuts the ligament at the top of the carpal tunnel. This makes more room in the tunnel and relieves pressure on the nerve. Surgery usually works to ease symptoms. But in some cases it does not completely get rid of numbness or pain.

How can you keep carpal tunnel syndrome from coming back?
To keep carpal tunnel syndrome from coming back, take care of your basic health. Stay at a healthy weight. Don't smoke. Exercise to stay strong and flexible. If you have a long-term health problem, such as arthritis or diabetes, follow your doctor’s advice for keeping your condition under control.

You can also try to take good care of your wrists and hands:
-Try to keep your wrist in a neutral position.
-Use your whole hand-not just your fingers-to hold objects.
-When you type, keep your wrists straight, with your hands a little higher than your wrists. Relax your shoulders when your arms are at your sides.
-If you can, switch hands often when you repeat movements.


http://www.youtube.com/watch?v=xuqcfRG2phk - carpal tunnel release surgery
http://www.youtube.com/watch?v=M4hTY1vyrxg - endoscopic surgery
http://www.youtube.com/watch?v=4vYiqeeUWNU&feature=related - endoscopic surgery
http://www.youtube.com/watch?v=TG9Ucds-ElY - exercises

Muscles of the hand

Muscles of Hand
The intrinsic muscles of the hand are located in five compartment : Fig. 6.75A
• Thenar muscles in the thenar compartment: abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis.
• Adductor pollicis in the adductor compartment.
• Hypothenar muscles in the hypothenar compartment: abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi.
• Short muscles of the hand, the lumbricals, in the central compartment with the long flexor tendons.
• The interossei in separate interosseous compartments between the metacarpals.
THENAR MUSCLES
The thenar muscles form the thenar eminence on the lateral surface of the palm and are chiefly responsible for opposition of the thumb. Normal movement of the thumb is important for the precise activities of the hand. The high degree of freedom of movements of the thumb results from the 1st metacarpal being independent, with mobile joints at both ends.
• Extension: extensor pollicis longus, extensor pollicis brevis, and abductor pollicis longus.
• Flexion: flexor pollicis longus and flexor pollicis brevis.
• Abduction: abductor pollicis longus and abductor pollicis brevis.
• Adduction: adductor pollicis and 1st dorsal interosseous.
• Opposition: opponens pollicis. This movement occurs at the carpometacarpal joint and results in a “cupping” of the palm. Bringing the tip of the thumb into contact with the 5th finger or any of the other fingers involves considerably more movement than can be produced by the opponens pollicis alone.
Abductor Pollicis Brevis.
The abductor pollicis brevis (APB), the short abductor of the thumb, forms the anterolateral part of the thenar eminence. In addition to abducting the thumb, the APB assists the opponens pollicis during the early stages of opposition by rotating its proximal phalanx slightly medially.


Flexor Pollicis Brevis.
The flexor pollicis brevis (FPB), the short flexor of the thumb, is located medial to the APB. Its two bellies, located on opposite sides of the tendon of the FPL, share (with each other and often with the APB) a common, sesamoid-containing tendon at their distal attachment. The bellies usually differ in their innervation: The larger superficial head of the FPB is innervated by the recurrent branch of the median nerve, whereas the smaller deep head is usually innervated by the deep palmar branch of the ulnar nerve. The FPB flexes the thumb at the carpometacarpal and metacarpophalangeal joints and aids in opposition of the thumb.

Opponens Pollicis.
The opponens pollicis is a quadrangular muscle that lies deep to the APB and lateral to the FPB. The opponens pollicis opposes the thumb, the most important thumb movement. It flexes and rotates the 1st metacarpal medially at the carpometacarpal joint during opposition; this movement occurs when picking up an object. During opposition, the tip of the thumb is brought into contact with the pad of the little finger.

ADDUCTOR POLLICIS
The adductor pollicis is located in the adductor compartment of the hand. The fan-shaped muscle has two heads of origin, which are separated by the radial artery as it enters the palm to form the deep palmar arch. Its tendon usually contains a sesamoid bone. The adductor pollicis adducts the thumb, moving the thumb to the palm of the hand, thereby giving power to the grip.

HYPOTHENAR MUSCLES
The hypothenar muscles (abductor digiti minimi, flexor digiti minimi brevis, and opponens digiti minimi) produce the hypothenar eminence on the medial side of the palm and move the little finger .These muscles are in the hypothenar compartment with the 5th metacarpal .
Abductor Digiti Minimi.
The abductor digiti minimi is the most superficial of the three muscles forming the hypothenar eminence. The abductor digiti minimi abducts the 5th finger and helps flex its proximal phalanx.
Flexor Digiti Minimi Brevis.
The flexor digiti minimi brevis is variable in size; it lies lateral to the abductor digiti minimi. The flexor digiti minimi brevis flexes the proximal phalanx of the 5th finger at the metacarpophalangeal joint.
Opponens Digiti Minimi.
The opponens digiti minimi is a quadrangular muscle that lies deep to the abductor and flexor muscles of the 5th finger. The opponens digiti minimi draws the 5th metacarpal anteriorly and rotates it laterally, thereby deepening the hollow of the palm and bringing the 5th finger into opposition with the thumb. Like the opponens pollicis, the opponens digiti minimi acts exclusively at the carpometacarpal joint.
Palmaris Brevis.
The palmaris brevis is a small, thin muscle in the subcutaneous tissue of the hypothenar eminence ; it is not in the hypothenar compartment. The palmaris brevis wrinkles the skin of the hypothenar eminence and deepens the hollow of the palm, thereby aiding the palmar grip. The palmaris brevis covers and protects the ulnar nerve and artery. It is attached proximally to the medial border of the palmar aponeurosis and to the skin on the medial border of the hand.

SHORT MUSCLES OF HAND
The short muscles of the hand are the lumbricals and interossei.

Lumbricals.
The four slender lumbrical muscles were named because of their worm-like form (L. lumbricus, earthworm. The lumbricals flex the fingers at the metacarpophalangeal joints and extend the interphalangeal joints.

Interossei.
The four dorsal interosseous muscles (dorsal interossei) are located between the metacarpals; the three palmar interosseous muscles (palmar interossei) are on the palmar surfaces of the metacarpals in the interosseous compartment of the hand .The 1st dorsal interosseous muscle is easy to palpate; oppose the thumb firmly against the index finger and it can be easily felt. Some authors describe four palmar interossei; in so doing, they are including the deep head of the FPB because of its similar innervation and placement on the thumb. The four dorsal interossei abduct the fingers, and the three palmar interossei adduct them .
A mnemonic device is to make acronyms of dorsal abduct (DAB) and palmar adduct (PAD). Acting together, the dorsal and palmar interossei and the lumbricals produce flexion at the metacarpophalangeal joints and extension of the interphalangeal joints (the so-called Z-movement). This occurs because of their attachment to the lateral bands of the extensor expansions .
Understanding the Z-movement is useful because it is the opposite of claw hand, which occurs in ulnar paralysis when the interossei and the 3rd and 4th lumbricals are incapable of acting together to produce the Z-movement .

Risk Factors & Symptoms of Carpal Tunnel Syndrome

Risk Factors of Carpal Tunnel Syndrome

Occupation

Jobs that require repetitive motion of the forearm, wrist and hand increase the risk of developing Carpal Tunnel Syndrome. Combining force, especially uncontrolled, external forces, heighten the risks. Some occupations of concern are:
• Manual Labor
• Meat Packing
• Fish Packing
• Lumber Jacks
• Vibrating Equipment Operators
• Construction Workers
• Vehicle Assembly Workers
• Truck or Cab Drivers
• Typists
• Computer Programmers

Hobbies

Much like jobs, passionate hobbyists can heighten the risk of developing Carpal Tunnel Syndrome. Hobbies that require motion of the forearm, wrist and hand increase risk, especially if that hobby is performed sitting down. Some hobbies of concern are:
• Knitting
• Crocheting
• Needlepoint
• Crossstitch
• Sewing
• Quilting
• Beading
• Woodworking
• Gardening
• Cooking
• Video Gaming
• Card Playing

Age, Sex and Pregnancy

• Carpal Tunnel Syndrome develops in more people aged 40-60.
• Statistically women tend to develop Carpal Tunnel Syndrome more than men.
• Pregnant women may develop symptoms due to fluid retention.
Health Issues
A number of health issues can contribute to developing Carpal Tunnel Syndrome either because they share similar causes or their effects on the body heighten the risk. Either way one may be a warning sign for another. Some health issues are:
• Diabetes
• Hypothyroidism
• Rheumatoid Arthritis
• Systemic Lupus Erythematosus
• Hepatitis C
• Down's Syndrome
• Multiple Sclerosis
• Menopause

Physical Issues

• Since Carpal Tunnel Syndrome is caused by friction in the Carpal Tunnel, having a small Carpal Tunnel is a risk. This may be a genetic trait leading towards Carpal Tunnel Syndrome.
• Having a square wrist where the width is roughly equal to the thickness, instead of a typical rectangular shape, may heighten the risk. A square wrist may imply a small Carpal Tunnel as well.
• Obesity can heighten the risk of many repetitive stress injuries including Carpal Tunnel Syndrome.

Other Issues

Some other issues that can increase the risk of developing Carpal Tunnel Syndrome are:
• Stress
• Cigarette Smoking
• A Bad Diet

Symptoms of Carpal Tunnel Syndrome

Early detection and treatment of Carpal Tunnel Syndrome is important to checking the progression of this debilitating syndrome, and yet some of the early symptoms are subtle and can be easily mistaken for other issues.
The first symptom people usually notice is that their hand and fingers become numb and tingling while they are sleeping causing them to wake up frequently during the night. Most people do not even realize that this is a symptom of Carpal Tunnel Syndrome and attribute the numb feeling to sleeping on their hands in an awkward position, cutting off blood circulation. Routine Sleep interruption from any cause has serious health implications and should be addressed with a strong sense of urgency (more details below).

- Sleep interruption from numb hands and tingling fingers
- Waking up -- Numbness in Hand at Night and Pain in Wrist
- Hand Pain and or Wrist Pain
- Weakness in Hand and Wrist - loss of hand muscles
- Pain Radiating up the Forearm - Poor Circulation, Hands falling asleep
- Cold Hands - Forearms warm - Loss of Hand Grip Strength
- Loss of Feeling Sensation in Fingers & Thumb - Dropping Objects - Forks - Glasses - Pen - etc.
- Numbness in Fingers or Tingling - Index, Middle & Ring Finger - Numbness in Thumb

- Loss of fine motor skills in hands - Clumsiness in Hands
- Aching Shoulders and Neck
Most Frustrating Results Patients Report Due to CTS Symptoms
- Lost Time at Work and Unproductive Daytime Sleepiness - Inability to Button Buttons, Tie Shoes, Turn Key, Apply Make-up -etc.
- Interruption of Earnings - Day Time Grogginess Affects Safety and Effectiveness at Work
- High Blood Pressure and Poor Health from Chronic Sleep Loss - Irritability Often Impacts Valued Relationships

A more detailed description of symptoms of chronic Carpal Tunnel Syndrome include:

Cold hands with warm forearms due to constriction of blood circulation in and around the carpal tunnel. Restricted blood circulation is a contributing factor to chronic Carpal Tunnel Syndrome.

Burning pain that radiates up the center of the forearm -as far as the shoulder and neck.

Difficulty gripping the steering wheel and overall decreasing grip strength as the hand muscles atrophy due to pain and lower levels of hand activity.

Clumsiness with hands, Routinely dropping objects or the inability to make a fist.

Loss of fine motor skills in the hand, inhibiting such tasks as writing, tying a shoe, working a mouse, picking up coins, buttoning a shirt or coat, threading a needle, doing needlepoint, etc.

Weak hands and inability to support one's self with hands on stairs, or climbing into a truck or on a ladder, or when balancing with a cane or in other precarious situations.

Inhibited hand and wrist movement due to pain, and numb tingling hands or tingling fingers.

Loss of feeling or swollen sensations in the hand or fingers

Finger Pain, finger numbness and/or finger clumsiness particularly in the thumb and/or in the index or middle fingers. (the pinky or little finger is not affected or controlled by the median Nerve nor is it generally associated with Carpal Tunnel Syndrome).

Constant aching of the upper shoulder and neck is common as the pain follows the nerve path up to the nerve center in the brain.

Hand dysfunction can lead to lost earnings, time away from work and loss of self esteem as a contributor at work and at home, some suffers even experience depression.

Routine Sleep Interruption - CTS sufferers often complain that they wake up 2 to 10 times per night due to numb tingling hands and that pins and needles feeling. Most sufferers find it extremely annoying to be awakened constantly with tingling fingers and numb hands. In more mild cases people wake up in the morning with numb tingling hands. Without treatment mild Carpal Tunnel Syndrome symptoms will progress to chronic sleep loss. Routine Sleep interruption has serious health implications and should be managed with a strong sense of urgency. For drivers and heavy equipment operators, the safety implications of routine sleep interruption and day time sleepiness requires immediate proactive therapy. Routine chronic sleep disorders have been linked directly to cardiopulmonary disease, high blood pressure, dyslipidemia, heart arrhythmia, insulin resistance, vascular inflammation, migraines, psychological disorders, day time sleepiness, etc. Sleep loss can be one of the most serious and debilitating issues associated with the Carpal Tunnel condition. Day time groggyness inhibits clear thinking and affects everything you do from driving a vehicle to carrying out the simplest of tasks.

Shooting Hand Pain or Wrist Pain that suddenly runs up the forearm and can also shoot down to the fingers and thumb.

Numbness in hands at night, tingling hands, swollen hands,Numb fingers, tingling fingers, finger numbness, swollen fingers, Thumb Numbness, Tingling Thumbs or Pain in Thumbs.

Investigation of CTS

WORK RELATED CTS

CTS are seen in many work situations requiring rapid finger and wrist motion under load, such as meat workers and process workers. A type of flexor tenosynovitis develops and thus nerve compression in the tight tunnel. It is advisable to arrange confirmatory investigations by nerve conduction studies and electromyography for this work-induced overuse disorder.

Simple clinical tests

To assist and confirming the diagnosis (relatively low sensitvity and specificity).

The tinel’s test

· Hold the wrist in a neutral or flexed position and tap over the median nerve at the flexor surface (anterior surface) of the wrist. This should be over the retinaculum just lateral to the palmaris longus tendon (if present) and the tendons of flexor digitorium superficialis.

· A positive Tinel’s sign produces a tingling sensation (usually without pain) in the distribution of the median nerve.

The phalen’s test

· The patient approximates the dorsum of both hands, one to the other, with wrists maximally flexed and fingers pointing downwards.

· This position is held for 60 seconds.

· The positive test reproduces tingling and numbness along the distribution of the median nerve.

Electrodiagnostic Test

To analyze the electric waveforms of nerves and muscles to detect median nerve compression in the carpal tunnel are the best methods for confirming a diagnosis of CTS at this time

Nerve conduction studies

· To perform nerve conduction studies, surface electrodes are first fastened to the hand and wrist.

· Small electric shocks are then applied to the nerves in the fingers, wrist, and forearm to measure the speed of conduction of sensory and motor nerve fibers.

· In suspected cases of CTS, nerve conduction tests can identify over 85% of true carpal tunnel syndrome cases and eliminate 95% of those that are not true CTS. They are less accurate in identifying mild CTS. Patients should be sure their practitioners perform tests that compare a number of internal responses--not just routine testing that records only the responses of thenar muscles (located in the palm at the base of the thumb) and second or third fingers. These tests can also detect causes of symptoms that mimic CTS but should be attributed to other problems, such as pinched nerves in the neck or elbow or thoracic outlet syndrome.

electromyography

· To perform electromyography, a fine, sterile, wire electrode is inserted briefly into a muscle and the electrical activity is displayed on a viewing screen.

· Electromyography can be quite painful and is less accurate than nerve conduction. Some experts question, in fact, whether it adds any valuable diagnostic information. They suggest it be limited to unusual cases or when other tests indicate that the condition is aggressive and may increase the risk for rapid, significant injury.

Complication and prognosis of CTS

Prognosis

• CTS can range from a minor inconvenience to a disabling condition, depending on its cause and persistence and the individual characteristics of the patient. Many cases of CTS are mild, and when symptoms don't last long, they often resolve (disappear) on their own. Once a woman with pregnancy-associated CTS gives birth, for instance, the swelling in her wrists and other symptoms almost always subside.
  
• CTS during pregnancy seem to be less severe than idiopathic CTS and has milder course with fewer cases requiring surgical treatment.
  
• Proper treatment of other medical conditions that cause CTS can often help reduce wrist swelling.
  
• Prognosis is excellent with proper treatment
  
• Whether any conservative management can prevent progression is unclear.
  
• Even with surgical release, it appears that the syndrome recurs to some degree in a significant number of cases (possibly in up to one third after 5 years).²⁰
  
  
• Despite treatment, some patients may have residual fingertip numbness.
  
• Initially, approximately 90% of mild to moderate CTS cases respond to conservative management. Over time, however, a number of patients progress to requiring surgery.
  
• Patients with CTS secondary to underlying pathology (eg, diabetes, wrist fracture) tend to have a less favorable prognosis than do those with no apparent underlying cause.
  

Complications

• Basically, the complications of CTS are:
  
  • Muscle weakness
    
  • Peripheral neuropathy
    
  • Paresthesia
    
• If the condition is treated properly, there are usually no complications.
  
• Carpal tunnel syndrome (CTS) appears to be progressive over time (although with considerable fluctuations from week to week) and can lead to permanent median nerve damage.
  
• If untreated, carpal tunnel syndrome may continue to increase median nerve damage, leading to permanent impairment and disability. (chronic hand weakness and numbness followed by chronic disability)
  
• Some individuals can develop chronic wrist and hand pain (with or without reflex sympathetic dystrophy).
  

Complications of surgery

Treatment failure and complication rates of CTS surgery vary.

Complications after surgery may include the following:

• Nerve damage with tingling and numbness (usually temporary)
  
• Infection
  
• Scarring
  
• Pain
  
• Stiffness
  
• Loss of some wrist strength is a complication that affects 10% to a third of patients. Endoscopy may have better results than open release. Some patients who have jobs requiring significant strength of the hand and wrist may not be able to perform them after surgery. These workers may also have problems in other parts of the upper body, including elbows and shoulders. These problems do not go away with surgery and can persist. Studies indicate that 10 - 15% of patients change jobs after a CTS operation.
  

If pain and symptoms return, the release procedure may be repeated.

Reasons for procedure failure include:

• Incomplete release of the ligament
  
• Extensive scarring
  
• Recurrence of the disorder due to underlying medical conditions
  

Patients who had open release surgery appear more likely to require repeat operations compared with those who have had endoscopic surgery.

Reference:

1. http://emedicine.medscape.com/article/822792-followup
   
2. http://health.nytimes.com/health/guides/disease/carpal-tunnel-syndrome/prognosis.html
   
3. http://emedicine.medscape.com/article/327330-followup
   
4. http://www.nlm.nih.gov/medlineplus/ency/article/000433.htm
   
5. http://www.umm.edu/patiented/articles/what_surgical_procedures_carpal_tunnel_syndrome_000034_9.htm
   

Carpal Tunnel

This website gives a good overview on everything-you-need-to-know-about carpal tunnel syndrome.

http://emedicine.medscape.com/article/327330-overview

Have an ameoba day! (:

Carpal Tunnel Syndrome

What is carpal tunnel syndrome?

Carpal tunnel syndrome occurs when the median nerve, which runs from the forearm into the hand, becomes pressed or squeezed at the wrist. The median nerve controls sensations to the palm side of the thumb and fingers (although not the little finger), as well as impulses to some small muscles in the hand that allow the fingers and thumb to move. The carpal tunnel - a narrow, rigid passageway of ligament and bones at the base of the hand - houses the median nerve and tendons. Sometimes, thickening from irritated tendons or other swelling narrows the tunnel and causes the median nerve to be compressed. The result may be pain, weakness, or numbness in the hand and wrist, radiating up the arm. Although painful sensations may indicate other conditions, carpal tunnel syndrome is the most common and widely known of the entrapment neuropathies in which the body's peripheral nerves are compressed or traumatized.

What are the symptoms of carpal tunnel syndrome?

Symptoms usually start gradually, with frequent burning, tingling, or itching numbness in the palm of the hand and the fingers, especially the thumb and the index and middle fingers. Some carpal tunnel sufferers say their fingers feel useless and swollen, even though little or no swelling is apparent. The symptoms often first appear in one or both hands during the night, since many people sleep with flexed wrists. A person with carpal tunnel syndrome may wake up feeling the need to "shake out" the hand or wrist. As symptoms worsen, people might feel tingling during the day. Decreased grip strength may make it difficult to form a fist, grasp small objects, or perform other manual tasks. In chronic and/or untreated cases, the muscles at the base of the thumb may waste away. Some people are unable to tell between hot and cold by touch.


What are the causes of carpal tunnel syndrome?

Carpal tunnel syndrome is often the result of a combination of factors that increase pressure on the median nerve and tendons in the carpal tunnel, rather than a problem with the nerve itself. Most likely the disorder is due to a congenital predisposition - the carpal tunnel is simply smaller in some people than in others. Other contributing factors include trauma or injury to the wrist that cause swelling, such as sprain or fracture; overactivity of the pituitary gland; hypothyroidism; rheumatoid arthritis; mechanical problems in the wrist joint; work stress; repeated use of vibrating hand tools; fluid retention during pregnancy or menopause; or the development of a cyst or tumor in the canal. In some cases no cause can be identified.

There is little clinical data to prove whether repetitive and forceful movements of the hand and wrist during work or leisure activities can cause carpal tunnel syndrome. Repeated motions performed in the course of normal work or other daily activities can result in repetitive motion disorders such as bursitis and tendonitis. Writer's cramp - a condition in which a lack of fine motor skill coordination and ache and pressure in the fingers, wrist, or forearm is brought on by repetitive activity - is not a symptom of carpal tunnel syndrome.


Who is at risk of developing carpal tunnel syndrome?

Women are three times more likely than men to develop carpal tunnel syndrome, perhaps because the carpal tunnel itself may be smaller in women than in men. The dominant hand is usually affected first and produces the most severe pain. Persons with diabetes or other metabolic disorders that directly affect the body's nerves and make them more susceptible to compression are also at high risk. Carpal tunnel syndrome usually occurs only in adults.

The risk of developing carpal tunnel syndrome is not confined to people in a single industry or job, but is especially common in those performing assembly line work - manufacturing, sewing, finishing, cleaning, and meat, poultry, or fish packing. In fact, carpal tunnel syndrome is three times more common among assemblers than among data-entry personnel. A 2001 study by the Mayo Clinic found heavy computer use (up to 7 hours a day) did not increase a person's risk of developing carpal tunnel syndrome.

During 1998, an estimated three of every 10,000 workers lost time from work because of carpal tunnel syndrome. Half of these workers missed more than 10 days of work. The average lifetime cost of carpal tunnel syndrome, including medical bills and lost time from work, is estimated to be about $30,000 for each injured worker.

How is carpal tunnel syndrome diagnosed?

Early diagnosis and treatment are important to avoid permanent damage to the median nerve. A physical examination of the hands, arms, shoulders, and neck can help determine if the patient's complaints are related to daily activities or to an underlying disorder, and can rule out other painful conditions that mimic carpal tunnel syndrome. The wrist is examined for tenderness, swelling, warmth, and discoloration. Each finger should be tested for sensation, and the muscles at the base of the hand should be examined for strength and signs of atrophy. Routine laboratory tests and X-rays can reveal diabetes, arthritis, and fractures.

Physicians can use specific tests to try to produce the symptoms of carpal tunnel syndrome. In the Tinel test, the doctor taps on or presses on the median nerve in the patient's wrist. The test is positive when tingling in the fingers or a resultant shock-like sensation occurs. The Phalen, or wrist-flexion, test involves having the patient hold his or her forearms upright by pointing the fingers down and pressing the backs of the hands together. The presence of carpal tunnel syndrome is suggested if one or more symptoms, such as tingling or increasing numbness, is felt in the fingers within 1 minute. Doctors may also ask patients to try to make a movement that brings on symptoms.

Often it is necessary to confirm the diagnosis by use of electrodiagnostic tests. In a nerve conduction study, electrodes are placed on the hand and wrist. Small electric shocks are applied and the speed with which nerves transmit impulses is measured. In electromyography, a fine needle is inserted into a muscle; electrical activity viewed on a screen can determine the severity of damage to the median nerve. Ultrasound imaging can show impaired movement of the median nerve. Magnetic resonance imaging (MRI) can show the anatomy of the wrist but to date has not been especially useful in diagnosing carpal tunnel syndrome.

Carpal Tunnel Syndrome Surgery Videos

Carpal Tunnel Syndrome Fact Sheet
PDF file giving a brief overview of the carpal tunnel syndrome.
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Clear-cut, easy to understand animations of the open carpal tunnel release and the endoscopic carpal tunnel release surgeries.
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Real footage of the traditional open carpal tunnel release surgery. Unfortunately, there's no narrative.
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Real footage of the endoscopic carpal tunnel release surgery. Brief narratives included.