Carpal Tunnel Syndrome
What is it?
Carpal tunnel syndrome is a painful disorder of the wrist and hand which is caused by irritation of the median nerve at the wrist. The carpal tunnel is a small circular structure located on the palm side of the wrist. Blood vessels, tendons and nerves travel through the tunnel and fan out to supply the palm and fingers of the hand. If this tunnel becomes inflamed and exerts pressure it causes numbness, tingling and pain in the hands and wrists.
Symptoms of carpal tunnel syndrome
Sufferers of carpal tunnel syndrome initially feel numbness and tingling of the hand in the thumb, index, middle and part of the fourth fingers. These sensations are often worse at night or on waking in the morning. As the disease progresses, patients can develop a burning sensation, cramping and weakness of the hand, and sharp shooting pains in the forearm. It may be difficult to clench the fist or grasp small objects.
Diagnosis of carpal tunnel syndrome
Symptoms may appear, or be worsened when the wrist is flexed for more than 60 seconds and then extended. This is known as the Phalen wrist flexion test. Carpal tunnel syndrome is strongly suggested when a nerve conduction test is abnormal. This test involves measuring the rate of speed of electrical impulses as they travel down a nerve. In carpal tunnel syndrome, the impulse slows as it goes through the carpal tunnel.
Causes of carpal tunnel syndrome
Any condition that exerts pressure on the median nerve can cause carpal tunnel syndrome. These include tendon inflammation resulting from repetitive work such as prolonged typing or assembly line work. Carpal tunnel syndrome is particularly common in those whose work requires grasping, twisting and turning, particularly if this involves repetitive vibration. Office workers who use excessive force while typing on their computer keyboards are at increased risk of carpal tunnel syndrome. Some sports such as rowing, golf, tennis, skiing and archery may also cause carpal tunnel syndrome, as can any condition which causes swelling or compression on nerves. These include sprains, obesity, pregnancy, hypothyroidism, arthritis and diabetes.
Carpal tunnel syndrome may also be referred to as cumulative trauma disorder, repetitive stress injury or overuse injury. It is most common in middle age and tends to affect women more than men, especially those who are overweight, pregnant or menopausal.
Treatment of carpal tunnel syndrome
Initial treatment of carpal tunnel syndrome involves rest and stopping or modifying the activities which worsen symptoms. Immobilization of the wrist in a splint, cool baths or cold compresses may also be useful. In cases where obesity, arthritis or other conditions are involved, treatment of the underlying cause is important.
Several types of medication can be used to treat carpal tunnel syndrome including nonsteroidal anti-inflammatory drugs and corticosteroids. Complete immobilization of the wrist in a cast or surgery to relieve compression may be necessary in severe cases. Physical therapies such as massage, stretching and gentle exercises are also useful and are particularly important after surgery in order to regain full hand use. Acupuncture and chiropractic treatments have also been used with some success.
Vitamins, minerals and carpal tunnel syndrome
B vitamins
A vitamin B6 deficiency may play a part in the development of carpal tunnel syndrome. Several small scale studies have found low vitamin B6 levels in sufferers of the disease.1 Some research suggests that treatment with supplements can improve symptoms which may reduce the necessity of surgery in some patients.2
Some recent studies have cast doubt on these results. In a study of 125 randomly selected industrial plant workers, vitamin B6 levels were measured and the subjects filled out questionnaires and underwent nerve function tests. The researchers did not find a link between vitamin B6 and carpal tunnel syndrome.3 Vitamin B6 has been shown to change pain thresholds in clinical and laboratory studies which may explain studies which have shown significant improvements in pain scores when nerve conduction test results showed only mild improvements.
Vitamin B6 supplements may be useful in the treatment of carpal tunnel syndrome but intake should not exceed 100 mg per day as large doses can cause nerve damage. Some practitioners use higher doses but this should only be done under supervision. Some experts believe that a therapeutic effect may take at least three months to become apparent.
Riboflavin may also help to relieve the symptoms of carpal tunnel syndrome. Combining riboflavin and vitamin B6 may be more effective than treatment with B6 alone. 4,5 Riboflavin is involved in the conversion of vitamin B6 to its active form.
Nutrients and carpal tunnel syndrome
Other nutrients such as antioxidants and essential fatty acids may be useful in the treatment of carpal tunnel syndrome as they have anti-inflammatory effects.
Herbal medicine and carpal tunnel syndrome
St. John's wort (Hypericum perforatum) is a useful herb for joint, muscle, or nerve trauma and it has demonstrated anti-inflammatory effects in scientific studies. Rubbing oil of St. John's wort on the wrist may be useful in relieving the symptoms of carpal tunnel syndrome. Ginger (Zingiber officinale) is also anti-inflammatory and may also be useful if applied to the affected area.