Carpal tunnel syndrome is one of the most common conditions affecting the hand. It occurs when the large median nerve is compressed as it passes through the carpal tunnel at the wrist. This can cause numbness, pins and needles, pain and weakness in the hand.
Mr Robert Farnell is an experienced specialist Consultant Orthopaedic Hand and Wrist Surgeon who has been working in Leeds for over 25 years. He exclusively treats conditions affecting the adult hand and wrist, including carpal tunnel syndrome, trigger finger and thumb, thumb arthritis and Dupuytren’s disease.
What is carpal tunnel syndrome?
Carpal tunnel syndrome is caused by pressure on the median nerve as it passes through a narrow space at the wrist called the carpal tunnel. The median nerve supplies feeling in most of the hand, but not usually the little finger. It also supplies some of the muscles at the base of the thumb.
When the nerve becomes compressed, it can affect sensation, grip strength and fine hand function. In the early stages, symptoms may come and go. If the condition progresses, numbness and weakness can become more constant and it may become permanent.
Figure 1: The carpal tunnel at the wrist and the median nerve passing through the tunnel.
Symptoms of carpal tunnel syndrome
Symptoms of carpal tunnel syndrome usually involve one or more of the following:
1. Numbness, tingling or pins and needles
Altered feeling, numbness or pins and needles are common symptoms. These usually affect the thumb, index finger, middle finger and part of the ring finger, but the little finger can be affected. Symptoms may be worse when the wrist is bent, such as when reading, driving or holding a phone.
Many people notice symptoms at night and may wake with a numb, painful hand. Hanging the hand out of bed or shaking it may temporarily relieve the symptoms. Some patients also describe generalised pain in the hand or forearm, or a sensation that the hand feels swollen.
2. Weakness in the hand
The hand may feel weak, particularly during activities that require pinch grip using the thumb. Examples include opening jars, turning bottle tops or gripping small objects. Dropping objects is a common complaint.
3. Difficulty feeling or handling small objects
Some patients find they cannot feel things properly with their fingers. This can make it difficult to recognise small objects such as coins, to fasten buttons or to perform other fine hand movements.
Why early assessment is important
In the early stages, symptoms are often intermittent and reversible. If left untreated, the altered feeling and numbness can become permanent. In more advanced cases, there may be wasting of the muscles at the base of the thumb.
Muscle wasting is best avoided through early assessment and treatment, as this may not recover fully once established.
What causes carpal tunnel syndrome?
Carpal tunnel syndrome may be associated with recognised medical conditions such as rheumatoid arthritis, thyroid disease, diabetes mellitus, inflammatory arthritis and pregnancy. However, in most people, no single cause is identified, which is called idiopathic.
The condition is more common in women and it may affect both hands.
Diagnosis of carpal tunnel syndrome
Diagnosis is usually based on your symptoms and clinical examination. During an outpatient appointment, Mr Farnell will listen to your symptoms, examine your hand and assess whether carpal tunnel syndrome is the likely cause.
In some cases, nerve tests may be recommended, particularly if the diagnosis is uncertain, if symptoms are severe or another nerve condition needs to be considered.
Find out what to expect at your outpatient appointment.
Treatment for carpal tunnel syndrome
Treatment depends on the severity of symptoms, how long they have been present and whether there is any evidence of permanent nerve change.
Non-surgical treatment
Non-surgical treatment includes wrist splints, activity modification or a steroid injection into the carpal tunnel.
A steroid injection can sometimes reduce symptoms and has the advantage of being a minor procedure which may be performed at the time of consultation. However, the amount and duration of symptom improvement can be difficult to predict and it is often temporary. There is also a small risk of directly injecting into the nerve.
Surgical treatment
Surgical treatment involves releasing the carpal tunnel. This procedure is called a carpal tunnel decompression.
Carpal tunnel decompression is one of the most common hand operations. It is usually performed under local anaesthetic as a day case procedure. During surgery, the flexor retinaculum, which forms the roof of the carpal tunnel, is released. This decompresses the median nerve.
The operation takes approximately 10 minutes on average and is not usually painful. After surgery, you will have a bulky bandage on your hand and wrist for up to two weeks. The hand will need to be elevated for several days after the procedure.
Recovery after carpal tunnel surgery
The operation is usually well tolerated and has a predictable outcome. Night-time symptoms and sensory symptoms often improve immediately or shortly after surgery.
However, sensation may not return fully to normal, particularly if the hand was constantly numb before surgery. Muscle wasting is usually permanent and does not usually recover.
Read more about post-operative care.
Possible complications
Complications after carpal tunnel decompression are uncommon and are usually minor.
Scar tenderness is the most common postoperative problem. Although it can be a nuisance, it usually resolves completely. Wound infection is seen in up to 1% of cases. Injury to the median nerve is recognised, but fortunately this is rare.
Concerned about carpal tunnel symptoms?
If you have numbness, pins and needles, night-time hand pain or weakness affecting your grip, Mr Robert Farnell can assess your symptoms and advise on the most appropriate treatment options.
Carpal tunnel syndrome FAQs
These answers are provided to help patients understand the key points about carpal tunnel syndrome, its symptoms and treatment options.
What are the first signs of carpal tunnel syndrome?
Early symptoms often include numbness, tingling or pins and needles in the thumb, index finger, middle finger and part of the ring finger. Symptoms may be worse at night or during activities where the wrist is bent.
Can carpal tunnel syndrome cause pain at night?
Yes. Night-time symptoms are common. Many patients wake with a numb, painful hand and find that shaking the hand or hanging it out of bed gives temporary relief.
Does carpal tunnel syndrome affect the little finger?
Carpal tunnel syndrome usually affects the area supplied by the median nerve which are the thumb, index finger, middle finger and part of the ring finger. Less commonly it can also affect the little finger.
Can carpal tunnel syndrome cause weakness?
Yes. Some patients notice weakness, especially with pinch grip using the thumb. This can make it harder to open jars, turn bottle tops or hold small objects securely.
When should I see a hand and wrist specialist?
You should consider specialist assessment if symptoms are persistent, worsening, waking you at night, affecting hand function or causing constant numbness or weakness.
Can carpal tunnel syndrome be treated without surgery?
Some patients improve with non-surgical treatment such as wrist splints, activity modification or a steroid injection. The best option depends on the severity and duration of symptoms.
What is carpal tunnel decompression?
Carpal tunnel decompression is an operation to release pressure on the median nerve at the wrist. It involves dividing the ligament forming the roof of the carpal tunnel.
How long does carpal tunnel surgery take?
The operation takes approximately 10 minutes on average and is usually performed under local anaesthetic as a day case procedure.
Will numbness improve after carpal tunnel surgery?
Night-time and sensory symptoms often improve quickly after surgery. However, if the hand was constantly numb before surgery, sensation may not return fully to normal.
Can muscle wasting from carpal tunnel syndrome recover?
Muscle wasting at the base of the thumb is usually permanent and does not usually recover. This is one reason why early assessment and treatment are important.