By Robert Dow Hoffman, M.D
Carpal tunnel syndrome is a common cause of pain and numbness in the hand. Estimates of its prevalence in this country are as high as 10 % of the population. But what is carpal tunnel syndrome, what causes it, and how is it treated?
Carpal tunnel syndrome describes a condition in which the median nerve is compressed as it travels across the wrist into the hand. The median nerve originates in the neck, travels down the arm, into the forearm, crosses the wrist and enters the hand. This nerve supplies sensation or feeling to the thumb, index, long, and part of the ring fingers and provides motor function to several small muscles in the hand. It leaves the forearm and enters the hand through a tunnel called the carpal tunnel. The floor and sides of the tunnel are formed by the wrist bones and the roof is formed by a dense band of connective tissue called the transverse carpal ligament. The median nerve is accompanied in the carpal tunnel by several tendons that flex the fingers and thumb appropriately called the flexor tendons. If, for whatever reason, the median nerve becomes compressed in this tunnel, it may begin to function abnormally, leading to pain, numbness, or weakness.
Most patients with carpal tunnel syndrome note a gradual onset of their symptoms without any specific history of injury. Numbness and tingling in the fingers are a common complaint, especially in the thumb, index, long and ring fingers. These symptoms can be particularly bothersome at night, often waking patients from sleep. Patients often will report worsening numbness and pain with activities such as driving, talking on the telephone, or fixing their hair. Initially, symptoms are intermittent but may progress and become constant leading to worsening pain and numbness. In advanced cases, patients may lose coordination with fine movements such as buttoning a shirt, start dropping objects, or note atrophy, or shrinking, of the muscles at the base of the thumb.
In the vast majority of patients, the cause of carpal tunnel syndrome is unknown. The risk of developing carpal tunnel syndrome is higher in patients with diabetes, thyroid problems, and patients with rheumatoid arthritis. Carpal tunnel syndrome is very common in pregnant women and usually resolves after delivery. Recently, there has been concern that repetitive tasks and motions at work may lead to carpal tunnel syndrome. This is a controversial topic and it is not entirely clear that workers who perform repetitive tasks have a higher incidence of carpal tunnel syndrome than the rest of the population.
After the diagnosis of carpal tunnel syndrome is made, treatment usually begins with a splint for the wrist along with medications to relieve pain. The splint is often worn at night and during the performance of activities that aggravate the pain and numbness. Sometimes an injection of a corticosteroid, often referred to as a “cortisone shot,” will be recommended to reduce the symptoms. These nonsurgical treatments and time lead to the resolution of the numbness and pain in the majority of cases. If these methods are unsuccessful, surgery may be recommended. Surgery for carpal tunnel syndrome involves cutting the roof of the carpal tunnel, the transverse carpal ligament. This surgery is successful in the vast majority of patients. The decision to perform surgery is based primarily on the duration and severity of symptoms and therefore varies greatly from patient to patient. An individual with carpal tunnel syndrome should discuss their treatment options with their doctor.
For more information about carpal tunnel syndrome or other orthopedic problems – contact Dr. Hoffman at Chatham Orthopaedics, 4425 Paulsen Street, Savannah, GA 31405,