Carpal Tunnel Syndrome (CTS): What is it?

Carpal Tunnel Syndrome is a common cause of numbness and pain in the hand and fingers. It affects women more often than men.

Anatomy

The carpal tunnel is a narrow, tubular structure on the palmar side of the wrist, bounded below and on the sides by the wrist bones and above by a tough connective tissue called the transverse carpal ligament.

Through the carpal tunnel pass the finger flexor tendons and the median nerve. The median nerve is responsible for sensation on the palmar surface of the thumb, index, middle, and half of the ring finger, and also innervates the thenar muscles — the muscles in the palm that move the thumb.

What causes carpal tunnel syndrome?

Carpal Tunnel Syndrome occurs when the tissues surrounding the tendons inside the canal become swollen, resulting in pressure on the median nerve. These tissues — sheaths — surround the tendons and lubricate them to facilitate finger movement. When swollen, the canal narrows and compresses the nerve.

Various factors can contribute to the syndrome’s development:

• Congenitally narrow carpal tunnel, possibly hereditary
• Chronic manual labor
• Hormonal changes during pregnancy
• Age, usually affecting older adults
• Medical conditions such as diabetes mellitus, rheumatoid arthritis, thyroid disease
• Recent injury to the hand or wrist, especially fractures of the distal forearm
• In most cases, however, no obvious cause is found.

What are the symptoms of carpal tunnel syndrome?

The most common symptoms are:

• Numbness and pain in the hand, often worsening at night. The numbness typically affects the thumb, index, middle, and half of the ring finger. Many patients wake up at night and shake their hand to relieve the symptoms.
• Strange sensations and pain that radiate centrally toward the forearm and shoulder
• A sensation of electric shocks in the fingers
• Less commonly, in advanced cases, hand weakness may occur, causing objects to drop or difficulty performing fine movements like buttoning a shirt. In these cases, thenar muscle atrophy (at the base of the thumb) may be visible.

Symptoms usually develop gradually. They are often worse at night and awaken the patient. During the day, symptoms frequently appear while driving, reading a book, or holding an object such as a phone. Shaking the hand often relieves symptoms.

How is the diagnosis made?

The suspicion of CTS is raised based on the patient’s history.

The clinical examination includes testing hand sensation and muscle strength. Specific clinical tests may be performed to try to reproduce the patient’s symptoms.

Paraclinical exams

Electromyography confirms the diagnosis by measuring the electrical conduction of the hand nerves.

Carpal Tunnel Syndrome: What is the appropriate treatment?

In most cases, CTS will gradually worsen if untreated.

Conservative Treatment

If diagnosed and treated early, CTS may improve without surgery.

If a known cause exists, such as a manual activity, stopping or modifying it early may be enough to halt progression and relieve symptoms.

If symptoms persist, a splint may be worn, mainly at night and during activities that worsen symptoms.

Nonsteroidal anti-inflammatory drugs (NSAIDs) may also help.

If symptoms continue despite this, local corticosteroid injections may be considered.

Surgical Treatment

If conservative treatment fails or in advanced cases, especially with muscle weakness, surgery is indicated.

Surgical technique: Surgery involves cutting the transverse carpal ligament to release the median nerve through a small incision of a few centimeters in the middle of the palm over the carpal tunnel. It can be done under local anesthesia and lasts 10-15 minutes. The patient usually does not require hospitalization and can leave the clinic after the procedure.

Arthroscopic technique: Instead of an incision in the palm, a 1-2 cm incision is made more proximally on the wrist under local anesthesia. Using a tiny camera, the surgeon visualizes the transverse ligament on a screen and cuts it with a special miniature knife, releasing the nerve from inside. This surgery takes 5-10 minutes.

Advantages of the arthroscopic method include:

• Less pain
• Faster recovery
• Immediate use of the hand after surgery
• No scars on the palm

Long-term results are similar with both techniques.

What are the recovery stages for carpal tunnel syndrome?

Usually, after surgery, the patient’s hand is bandaged and supported to reduce swelling. Finger movement is encouraged immediately to help prevent edema.

Stitches are typically removed after about 2 weeks.

Pain and numbness usually resolve quickly after surgery, but weakness may take longer depending on how long and how severely the nerve was compressed.

Daily activities are generally allowed soon after surgery, avoiding heavy labor.

Driving is usually possible shortly after surgery once the patient feels comfortable. Return to work depends on the job type and surgery method (arthroscopic or open), typically 10 days for arthroscopic and up to 3 weeks for open surgery, except for heavy manual work which may require longer.

Complications: Although complications are rare, the most common are:

• Hematoma
• Infection
• Nerve injury