Carpal Tunnel Syndrome:
Early Diagnosis is Key

By Troy Berg, MD

Carpal tunnel syndrome is a common condition that affects millions of people each year. It is caused by compression of a nerve (the median nerve) at the wrist and is the most common nerve compression syndrome of the upper extremity. It is treated by a variety of methods.

The carpal tunnel is a confined space in the wrist that contains many tendons as well as the median nerve. Abnormalities of the wrist bones or thickening of the ligament that covers the carpal canal make the space in the carpal tunnel smaller. Swelling of the tendons in the wrist, such as from repetitive overuse, takes up extra space in the carpal tunnel causing the median nerve to be compressed. Compression can also occur from tumors, abnormal muscles, or bleeding from a fracture. Nerve abnormalities, such as caused by diabetes, neck problems, and alcoholism, can also contribute to carpal tunnel syndrome. In the early stages of carpal tunnel syndrome the condition is usually reversible. However, permanent nerve damage and muscle weakness may occur in chronic, severe cases. Symptoms can occur when there is a disruption of the blood supply to the nerve.

Classic symptoms include numbness and tingling in the thumb, index, long and ring fingers. Painful sensations, called dysesthesias, can occur as well. The symptoms are often worse at night. They also tend to be worse when the wrist is in positions of extreme flexion or extension and with repetitive use of the hand. The dropping of objects is frequently noticed. In severe cases the muscles of the thumb atrophy and people notice weakness. The symptoms typically begin gradually, though they can also arise rapidly from an injury such as a broken wrist.

Diagnosis of carpal tunnel syndrome is made from a careful history and physical exam, and sometimes a specialized test called an EMG (Electromyogram)‹the recording of the changes in electric potential of muscle. Physical examination involves checking the sensation in the hand, tapping forcefully on the wrist over the median nerve (Tinels sign), and holding the wrist in a position of extreme flexion (Phalens maneuver). If there is decreased sensation, or if there is increased tingling with Tinels sign or Phalens maneuver, then carpal tunnel syndrome is likely present. It is also important to evaluate the neck to ensure that the symptoms are not from a neck problem. An EMG is sometimes necessary to confirm the diagnosis of carpal tunnel syndrome and to evaluate its severity.

Treatment of carpal tunnel syndrome is multi-faceted. It is important to accurately determine the cause of the carpal tunnel syndrome and to assess its severity. Carpal tunnel syndrome often arises from repetitive use of the hands in the workplace. Optimizing work stations and ergonomics are vital to treatment. Holding the wrist in a neutral position with a splint (to maximize the space available in the carpal tunnel) often helps. Splints are typically worn at night and during the day with repetitive activities. Oral anti-inflammatory medications are sometimes used. Injections of steroid medication (cortisone) can help as well. These non-operative treatment measures are most successful if symptoms are mild and have been present for less than a year.

Surgery is indicated for carpal tunnel syndrome that is in an advanced stage or that has not improved with non-operative measures. The goal of the surgery is to decompress, or relieve the pressure on, the median nerve. There are a variety of surgical techniques. Typically, an incision in the palm is made and then the ligament that covers the carpal tunnel is divided, thus, making more room for the median nerve. Relief of night pain is the most predictable outcome from surgery. Numbness and muscle weakness in severe, chronic cases may not completely recover.

Managing your activities is a key factor in preventing carpal tunnel syndrome. The use of good posture and proper mechanics in the workplace are vital. If you work with a keyboard, adjust your seat height so that your forearms are horizontal and your elbows are flexed at 90ò. Try to keep your wrists straight and not resting on the keyboards. Occasional breaks from repetitive activities can help prevent carpal tunnel syndrome and other repetitive overuse disorders.

Early diagnosis and treatment is key to successful treatment. Carpal tunnel syndrome commonly improves without surgery when treated in its early stages. A careful assessment by your health care provider will improve therapeutic results and help prevent its recurrence.

For more information, call Chippewa Valley Orthopedic and Sports Medicine ³ 715.832.1400