Carpal tunnel syndrome

Overview

Carpal tunnel syndrome (CTS) is a common condition that occurs when the median nerve, one of the main nerves supplying the hand, is compressed as it travels through the carpal tunnel in the wrist. The carpal tunnel is a narrow passageway surrounded by bones and ligaments. When the tunnel becomes narrowed or the tissues within it swell, pressure is placed on the median nerve, leading to symptoms such as numbness, tingling, and weakness in the hand. CTS can affect one or both hands and is most prevalent in adults aged 30 to 60.

Causes

Carpal tunnel syndrome is typically caused by anything that compresses or irritates the median nerve in the wrist. Common causes and risk factors include:

• Repetitive hand use: Repeated motions such as typing, assembly line work, or using vibrating tools

• Wrist anatomy: A smaller carpal tunnel or previous injury may predispose individuals to compression

• Medical conditions: Such as diabetes, hypothyroidism, rheumatoid arthritis, and obesity

• Fluid retention: Especially during pregnancy or menopause

• Genetics: A family history of CTS may increase risk

Symptoms

The symptoms of carpal tunnel syndrome often develop gradually and can vary in severity. Common signs include:

• Numbness or tingling: Especially in the thumb, index, middle, and part of the ring finger

• Hand weakness: Difficulty gripping objects or performing fine motor tasks

• Wrist pain: That may extend up the arm or be worse at night

• Shaking the hand: May temporarily relieve symptoms

• Loss of sensation: In advanced cases, leading to decreased hand coordination

Diagnosis

Diagnosing carpal tunnel syndrome typically involves a combination of physical examination, symptom history, and diagnostic testing:

• Physical exam: Assessing for wrist tenderness, weakness, or positive Tinel’s or Phalen’s sign

• Nerve conduction studies (NCS): Measure the speed and strength of electrical signals in the median nerve

• Electromyography (EMG): Evaluates muscle response to nerve stimulation

• Ultrasound or MRI: May be used to visualize swelling of the median nerve or underlying structural abnormalities

• Symptom evaluation: Considering timing, triggers, and distribution of symptoms

Treatment

Treatment for carpal tunnel syndrome depends on the severity of symptoms and the underlying cause. Options include:

• Conservative (non-surgical) treatments:

  • Wrist splinting, especially at night

  • Nonsteroidal anti-inflammatory drugs (NSAIDs) for pain relief

  • Activity modification to reduce repetitive strain

  • Corticosteroid injections to reduce inflammation

• Physical or occupational therapy: To strengthen the hand and improve ergonomics

• Surgical treatment:

  • Carpal tunnel release surgery, which involves cutting the ligament pressing on the median nerve

  • Performed via open or endoscopic technique

Prognosis

With early diagnosis and appropriate treatment, the prognosis for carpal tunnel syndrome is generally good. Most patients experience significant relief of symptoms with conservative or surgical management. In long-standing or severe cases, permanent nerve damage and muscle atrophy may occur if left untreated. Following ergonomic practices, addressing underlying medical conditions, and taking breaks during repetitive activities can help prevent recurrence or progression.