Carpal Tunnel Syndrome - Diagnosis

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's 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's 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 thicken and 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 and 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.