PATIENT INFORMATION
Carpal tunnel syndrome
A common condition caused by compression of the median nerve at the wrist.
What is carpal tunnel syndrome?
Carpal tunnel syndrome (CTS) is a common condition caused by compression of the median nerve as it passes through a narrow passage in the wrist called the carpal tunnel. The median nerve supplies sensation to the thumb, index finger, middle finger and part of the ring finger, and controls some of the small muscles at the base of the thumb.
When the nerve is compressed, symptoms may include:
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Numbness or tingling in the thumb, index, middle and ring fingers
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Burning or aching pain in the hand or wrist
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Symptoms that are worse at night or on waking
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Weakness of grip, difficulty with tasks such as buttoning clothes or opening jars, or dropping objects unexpectedly
Symptoms can affect one or both hands and may gradually worsen over time. Common risk factors include repetitive hand use, pregnancy, diabetes, thyroid disorders, rheumatoid arthritis and obesity.
Why have I been referred for NCS and EMG?
Your doctor may have recommended these tests to confirm whether your symptoms are due to carpal tunnel syndrome, assess the severity of median nerve compression, exclude other conditions such as peripheral neuropathy or cervical radiculopathy, and help guide treatment decisions, including whether surgery may be beneficial. Nerve conduction studies are considered the most reliable test for confirming carpal tunnel syndrome and grading its severity.
What to expect during the test
Nerve conduction studies: small electrodes are placed on the skin over the hand and wrist, and a mild electrical pulse is used to measure how quickly signals travel across the carpal tunnel. The sensation feels like a brief static shock and lasts only a few seconds.
EMG is not always required for carpal tunnel syndrome. It may be recommended if there is significant weakness, muscle wasting, or concern about another condition such as a pinched nerve in the neck. Read more about NCS/EMG.
Summary
Carpal tunnel syndrome is a very common and treatable condition. Nerve conduction studies are safe, specialised tests that confirm the diagnosis and assess severity. The results help determine the most appropriate treatment, which may include wrist splints, steroid injections, or surgery to relieve pressure on the nerve.