Carpal Tunnel Syndrome
Carpal tunnel syndrome is a common condition that can cause numbness, tingling, and weakness in the hand. It occurs when the median nerve, which runs through a narrow passageway in the wrist called the carpal tunnel, becomes compressed or irritated.
Understanding the Condition
The carpal tunnel is a narrow passageway on the palm side of the wrist, formed by bones and ligaments. The median nerve passes through this tunnel along with tendons that bend the fingers. When the tunnel narrows or when tissues surrounding the tendons swell, pressure on the median nerve can increase, potentially leading to the symptoms associated with carpal tunnel syndrome.
The condition may develop gradually, and symptoms often appear first at night or upon waking. Many people experience symptoms that come and go initially, but over time they may become more persistent if the underlying cause is not addressed.
Common Symptoms
People with carpal tunnel syndrome may experience a variety of symptoms in the hand and fingers. The thumb, index finger, middle finger, and ring finger are typically affected because these are the areas supplied by the median nerve.
Numbness, tingling, or a pins-and-needles sensation are commonly reported. Some people describe the sensation as similar to having the hand "fall asleep." Symptoms may be worse at night, potentially disrupting sleep, and can sometimes extend up the forearm.
Weakness in the hand, particularly affecting grip strength, may develop over time. Some individuals notice they drop objects more frequently or have difficulty with fine motor tasks such as buttoning clothing.
Potential Causes and Risk Factors
The exact cause of carpal tunnel syndrome is not always clear, but several factors may contribute to the development of the condition. These include anatomical factors such as a naturally smaller carpal tunnel, as well as conditions that can cause swelling or changes in the tissues within the tunnel.
Certain health conditions may be associated with increased risk, including diabetes, thyroid disorders, rheumatoid arthritis, and fluid retention during pregnancy. Repetitive hand motions, particularly those involving wrist flexion or extension, may also contribute in some cases.
The condition is more common in women than in men, which may be related to differences in wrist anatomy. Age is another factor, with the condition occurring more frequently in middle-aged and older adults.
Diagnosis
Diagnosis of carpal tunnel syndrome typically involves a combination of medical history, physical examination, and sometimes additional testing. A healthcare provider may ask about the pattern and duration of symptoms, as well as activities that may aggravate or relieve them.
During the physical examination, tests may be performed to reproduce symptoms or assess nerve function. These can include tapping on the wrist over the median nerve or holding the wrist in a flexed position to see if symptoms are provoked.
Electrodiagnostic studies, including nerve conduction studies and electromyography, may be used to evaluate the function of the median nerve and rule out other conditions. Imaging studies such as ultrasound or MRI are sometimes used to visualize the carpal tunnel structures.
Treatment Approaches
Treatment for carpal tunnel syndrome may vary depending on the severity of symptoms and individual circumstances. Non-surgical approaches are often tried first, particularly when symptoms are mild to moderate.
Wrist splinting, especially at night, may help relieve symptoms by keeping the wrist in a neutral position. Modifications to activities that aggravate symptoms may also be recommended. Anti-inflammatory medications and corticosteroid injections into the carpal tunnel are sometimes used to reduce swelling and relieve pressure on the nerve.
When conservative measures do not provide adequate relief, or when symptoms are severe, surgical treatment may be considered. Carpal tunnel release surgery involves cutting the ligament that forms the roof of the tunnel to reduce pressure on the median nerve. The procedure can be performed using open or endoscopic techniques.