Carpal Tunnel Syndrome

 

Physiology

At the base of the palm is a tight canal or "tunnel" through which tendons and nerves must pass on their way from the forearm to the hand and fingers. The nerve that passes through this narrow tunnel to reach the hand is called the Median Nerve. This narrow passage between the forearm and hand is what is known as the "Carpal Tunnel".

The Carpal Tunnel is normally quite snug and there is just barely enough room in it for the tendons and nerves that have to pass through it. If anything takes up extra room in the canal, things become too tight and the nerve in the canal becomes constricted or "pinched"

This pinching of the nerve (a medical condition referred to officially as Nerve Entrapment) causes numbness and tingling in the area of the hand that the nerve travels to. The condition that results when the Median Nerve is being pinched in The Carpal Tunnel is commonly referred to as Carpal Tunnel Syndrome or "CTS".

In actuality, the condition and its accompanying symptoms can be brought on by either a decrease in the size of the carpal tunnel OR an enlarging of the tissues inside the tunnel.

Carpal Tunnel Syndrome has received a lot of attention in recent years because of suggestions that it may be linked with occupations that require repeated use of the hands, such as typing on a computer keyboard or doing assembly work. In reality, many people develop this condition regardless of the type of work they do.

 

 

Cause

The most common cause of Carpal Tunnel Syndrome is inflammation of the tendons in the tunnel which can normally be attributed to repetitive use of the hand and/or wrist.

Repetitive Strain Injuries (RSIs) can happen to anyone whose work calls for long periods of steady hand movement, from musicians & dental hygienists to meat cutters & cashiers. RSIs tend to come with work that demands repeated grasping, turning and twisting; they are especially likely if the work requires repeated twisting or involves repetitive vibration, as in hammering nails or operating a power tool. Stressful hand, arm and neck positions - whether from working at a desk, long-distance driving or waiting on tables - only aggravate the potential for damage.

A number of sports can bring on repetitive stress injuries: Rowing, golf, tennis, downhill skiing, archery, competitive shooting and rock climbing are just a sampling of activities that stress the hand and wrist joints. Injuries and ailments that cause swelling or compression of soft tissue on nerves, such as sprains, leukemia, and rheumatoid arthritis, can lead to stress injuries.

Diabetes, thyroid problems, and other systemic disorders are also associated with discomfort from stressed nerves, as is the fluid accumulation that sometimes accompanies pregnancy. Some authorities believe that a pyridoxine (vitamin B6) deficiency can also induce the symptoms.

Fluid retention, a major contributor to CTS & RSI symptoms naturally occur with the usage of contraceptive pills. Post Menstrual Syndrome (PMS) also causes fluid retention as do many other medical conditions, all of which can result in Carpal Tunnel Syndrome symptoms.

 

 

Symptoms  

One of the first symptoms of CTS is gradual numbness in the areas supplied by the median nerve. This is quickly followed by pain where the nerve gives sensation in the hand. The hand may begin to feel like it's "asleep," especially in the early morning hours after a night's rest.

Pain may spread up the arm to the shoulder and even to the side of the neck. If the condition progresses, the thenar muscles of the thumb can weaken and atrophy, causing the hand to be clumsy when picking up a glass or cup. If the pressure keeps building in the carpal tunnel, the thenar muscles may actually begin to shrink (atrophy).

Touching the pad of the thumb to the tips of the other fingers becomes difficult, making it hard to grasp items such as a steering wheel, newspaper, or telephone.

 

  • A tingling or numb feeling in the hand and/or fingers;
  • Shooting pains in the wrist or forearm, and sometimes extending to the shoulder, neck and chest, or foot;
  • Difficulty clenching the fist or grasping small objects;

For many unfortunate sufferers, CTS has a pattern of flaring up through the night thereby making sleep difficult. CTS symptoms can also be expected to arise frequently while performing the activity that is the cause of the condition in the first place.

Assessment

Careful investigation usually shows that the little finger is unaffected. This can be a key piece of information to make the diagnosis. If you awaken with your hand asleep, pinch your little finger to see if it is numb also, and be sure to tell your doctor if it is or is not. Other complaints include numbness while using the hand for gripping activities, such as sweeping, hammering, or driving.
 

Treatments

  • Conservative Treatment

Activities that are causing your symptoms need to be changed or stopped if at all possible. Avoid repetitive hand motions, heavy grasping, holding onto vibrating tools, and positioning or working with your wrist bent down and out. If you smoke, talk to your doctor about ways to help you quit. Lose weight if you are overweight. Reduce your caffeine intake.

 

  • Wrist Brace

A wrist brace will sometimes decrease the symptoms in the early stages of CTS. A brace keeps the wrist in a resting position (not bent back nor bent down too far). When the wrist is in this position, the carpal tunnel is as big as it can be--so the nerve has as much room as possible inside the carpal tunnel. A brace can be especially helpful for easing the numbness and pain felt at night and can keep your hand from curling under as you sleep. The wrist brace can also be worn during the day to calm symptoms and rest the tissues in the carpal tunnel.

 

  • Physical Therapy

Your doctor may suggest that you work with a physical or occupational therapist. The main focus of treatment is to reduce or eliminate the cause of pressure in the carpal tunnel. Your therapist may check your workstation and the way you do your work tasks. Suggestions may be given about the use of healthy body alignment and wrist positions, helpful exercises, and tips on how to prevent future problems.

 

  • Surgical Treatment

If all attempts to control your symptoms fail, surgery may be suggested to reduce the pressure on the median nerve. Several different surgical procedures have been designed to relieve pressure on the median nerve. By releasing the pressure on the nerve, the blood supply to the nerve improves, and most people get relief of their symptoms.

 

However, if the nerve pressure has been going on a long time, the nerve may have thickened and scarred to the point that recovery after surgery is much slower.

The most common procedure is an open-incision technique, but some surgeons are using a newer procedure called endoscopic carpal tunnel release. Using a smaller incision and a fiber-optic TV camera, the doctor is able to see inside the carpal tunnel and release the transverse carpal ligament.