VOL: 101, ISSUE: 05, PAGE NO: 30
What is it?
- Carpal tunnel syndrome develops when the median nerve, which runs from the forearm into the hand, becomes compressed at the wrist.
- The median nerve controls some of the muscles that move the thumb and allows feeling in the hand.
- Swelling of irritated tendons may narrow the tunnel and compress the nerve, resulting in pain, weakness and numbness in the hand and wrist, which can radiate up the arm.
- Symptoms begin gradually with frequent burning, tingling, or itching numbness in the palm and the fingers, especially thumb, index and middle fingers. In time, symptoms can spread to the arm and shoulder.
- Some report their fingers feeling useless and swollen, even though there is little swelling.
- Onset often occurs in one or both hands during the night, since many people sleep with flexed wrists.
- As symptoms deteriorate, tingling can spread to the daytime.
- Decreased grip can make it hard to form a fist, grasp small objects, or perform other manual tasks.
- Fine movements, such as writing, may become increasingly difficult.
- In chronic cases the muscles at the base of the thumb may waste away and the ability to distinguish hot from cold may disappear. There may be permanent loss of feeling.
- In some people carpal tunnel syndrome occurs simply because their carpal tunnel is smaller.
- It may also result from the tunnel walls being compressed through repeated wrist movements, which put pressure on the nerve. The movements may be related to a person’s job, such as typing or using certain tools.
- The condition is more likely to develop if the wrist has been injured, for example fractured or sprained.
- The carpal tunnel may also be compressed through rheumatoid arthritis or in a condition called acromegaly, in which excess growth hormone is produced.
- Fluid retention due to kidney failure, underactive thyroid or pregnancy can also contribute to the condition as can changes to the median nerve itself during conditions such as diabetes.
- The wrist should be 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.
- There are specific tests that try to reproduce the symptoms of carpal tunnel syndrome, such as the Tinel test where the median nerve in the is tapped on or pressed.
- The diagnosis can be confirmed by 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 and electrical activity viewed on a screen can determine any damage to the median nerve.
- Ultrasound imaging can show impaired movement of the median nerve.
- Treatment aims to reduce the pressure on the median nerve.
- Wrist splints can be used to keep the wrist straight and avoid exerting pressure on the compressed nerve.
- Repetitive actions that may have caused the symptoms should be avoided where possible.
- Stretching exercises can aid blood flow to hand and arm muscles.
- Corticosteroids, steroid injections and prescription-only NSAIDs may all be prescribed to reduce symptoms.
- If symptoms deteriorate the only long-term option is surgery. In carpal tunnel release the carpal ligament is cut to make more space for the nerves and tendons. It is often day case surgery and may be done using an endoscope.