Carpal Tunnel Syndrome

Definition/diagnostic criteria Carpal Tunnel Syndrome (CTS) is a common condition characterised by pain, numbness, and tingling in the hand and arm. The condition occurs due to compression of the median nerve as it passes through the carpal tunnel in the wrist. Diagnosis is primarily clinical: key pointers are nocturnal symptoms, Tinel’s sign and Phalen’s test.

Epidemiology CTS is the most common entrapment neuropathy. The prevalence in the UK is 7–16%. It is more common in women than men, and it most often affects people aged 40-60 years. Risk factors include obesity, pregnancy, wrist injury, repetitive hand use, and certain health conditions like diabetes and rheumatoid arthritis.

Diagnosis
Clinical features: Patients typically present with symptoms of pain and paraesthesia in the thumb, index, middle and ring fingers, often worse at night. Symptoms may be relieved by shaking  the hand.

Tinel’s sign (tingling in the fingers induced by tapping over the median nerve) and Phalen’s test (numbness or tingling in the fingers after holding the wrists in a flexed position) are commonly used in clinical assessment. Thenar wasting suggests severe compression.

Investigations: While the diagnosis of CTS is primarily clinical, nerve conduction studies can confirm the diagnosis and assess severity.

Treatment Treatment options vary depending on the severity of symptoms and functional impairment.

• Non-surgical: Initial management includes wrist splinting, particularly at night, and corticosteroid injections. NSAIDs are often used, although their effectiveness specifically for CTS is unclear. Note that symptoms may resolve without treatment in about a third of patients within six months.
• Surgical: Carpal tunnel release surgery is considered for patients with severe or persistent symptoms. It involves cutting the ligament that forms the roof of the carpal tunnel to reduce pressure on the median nerve. Recurrence rates after decompression are between 0.3 and 12%.

Prognosis: The prognosis for CTS can vary. Non-surgical treatments can provide temporary relief but symptoms may recur. Surgical intervention usually provides more long-term relief. However, some patients may continue to experience symptoms or develop complications such as scar tenderness, nerve damage or infection.