Boniform: Diagnosis and investigation

One of the most important first steps in diagnosing CTS is to rule out any underlying medical disorders that may be contributing to the condition. Relying only on CTS symptoms, and personal or work histories may result in the failure to detect (and thus properly treat) underlying medical conditions that could be serious. If the doctor suspects that an underlying medical condition may be exacerbating the symptoms of CTS, laboratory tests will be performed. Tests for thyroid disease and rheumatoid arthritis may be helpful. The doctor may take an x-ray, for example, to check for arthritis or fractured bones.

Arthritic Conditions. Arthritic conditions, including rheumatoid arthritis, gout, and osteoarthritis, can all cause pain in the hands and fingers that may mimic carpal tunnel disease. The treatment for these conditions, however, is different.

Muscle and Nerve Diseases. Any disease or abnormality that affects the muscles and nerves, including those in the spine, may produce symptoms in the hand that mimic carpal tunnel syndrome.

How is carpal tunnel syndrome diagnosed?

- most accurately diagnosed using the patients' descriptions of symptoms, and electrodiagnostic tests that measure nerve conduction through the hand

Physicians can use specific tests to try to produce the symptoms of carpal tunnel syndrome.

1) 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.

2)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.

3)Pressure Provocation Test. The doctor presses over the carpal tunnel for 30 seconds to produce tingling or shock in the median nerve.

4)Tourniquet Test. This test employs an inflatable cuff that applies pressure over the median nerve to produce tingling or small shocks.

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.

Nerve conduction study.

In a variation of electromyography, two electrodes are taped to your skin. A small shock is passed through the median nerve to see if electrical impulses are slowed in the carpal tunnel.

Nerve conduction tests are fairly accurate when done on patients with more clear-cut symptoms of carpal tunnel syndrome. They are less accurate in identifying mild CTS, however.

Electromyogram.

Electromyography measures the tiny electrical discharges produced in muscles. A thin-needle electrode is inserted into the muscles your doctor wants to study. An instrument records the electrical activity in your muscle at rest and as you contract the muscle. This test can help determine if muscle damage has occurred.

Electromyography can be 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.

Portable electrodiagnostic testing. Portable electronic devices are being evaluated for measuring nerve conductivity. They are relatively quick and easy to use on a large scale in an industrial facility. However, these devices are not well studied in clinical trials.

Limitations. Electrodiagnostic studies are not well standardized, and certain conditions can skew the results of either test:

· Obesity can slow the speed of electrical conduction.

· Women and the elderly normally have slower conduction times than younger adult men.

EXTRA INFO:

Other Cumulative Trauma Disorders
Location	Description
The Median Nerve in Other Locations	Repetitive work can cause pressure on the median nerve in locations other than the wrist and can also affect other nerves in the arm and hand. The branch of the median nerve that runs through the palm of the hand can be damaged directly by repeated pounding or by the use of certain tools requiring a strong grip using the palm, such as needle-nosed pliers. The median nerve can also be pinched in the forearm.
Guyon Canal Syndrome (Commonly called ulnar tunnel syndrome)	The ulnar nerve can, like the median nerve, can be trapped as a result of repetitive stress. When this nerve is trapped, the condition is sometimes referred to as ulnar tunnel syndrome. It is more correctly known as Guyon canal syndrome, however, since this is the name of the passage through which the ulnar nerve passes. General symptoms are similar to carpal tunnel syndrome, but patients experience loss of sensation in the ring and little finger and in the outer half of the palm. It can be a separate problem, although it commonly occurs with CTS. In such cases, release surgery for CTS usually also relieves the ulnar nerve entrapment. The ulnar nerve can also be affected at the elbow.
De Quervain's Tenosynovitis	Tenosynovitis is swelling of the slippery covering of the tendons that move the thumb. When it causes pain on the side of the wrist and forearm right below the base of the thumb, it is known as De Quervain's tenosynovitis. (Finklestein's Test may help identify this. Make a fist that encloses the thumb, and bend the wrist sideways and down away from the thumb. If it causes pain, it is likely to be De Quervain's tenosynovitis.) It may be treated with splints or corticosteroid injections. In severe cases release surgery is effective.
Digital Flexor Tenosynovitis (Trigger or Snapping Finger)	Digital flexor tenosynovitis, commonly called trigger or snapping finger, is brought on when a tendon thickens, leaving the finger or thumb in a bent position. This disorder usually occurs when the tendons form a knot and may arise in those with hypothyroidism, diabetes, gout, rheumatoid arthritis, or connective tissue disorders. It can cause pain and a clicking sound when the trigger finger or thumb is bent and straightened. It can be effectively treated with corticosteroid injections.
Thoracic Outlet Syndrome	Thoracic outlet syndrome is caused by compression of nerves or blood vessels running down the neck into the arm. It can produce symptoms very similar to CTS. Other symptoms may include Raynaud's phenomenon (changes in sensation and temperature in the hand). The compression occurs at the first rib in the front of the shoulder. This may happen after an accident or simply from chronic slouching posture. A doctor may be able to diagnose the condition by detecting diminished blood flow in the arm as the patient raises the affected hand and turns his or her head toward the opposite side. Although the condition is uncommon, a correct diagnosis is important to differentiate it from CTS, since treatments differ. Surgery may be required to relieve pressure on the nerves and blood vessels.