Carpal Tunnel Syndrome
Carpal tunnel syndrome is very common and can cause many symptoms such as pins-and-needles, hand pain and night waking. It can be very distressing and severely impact on your quality of life.
Fortunately there are effective treatments for this – ranging from splints in early disease to surgery for more severe carpal tunnel syndrome.
Dr Simcock has answered some of the common questions here, and if you are concerned you may have carpal tunnel please phone for an appointment so you can discuss your treatment plan in depth.
To make an appointment
What is the carpal tunnel?
Beneath the base of the palm is a tunnel through which all the tendons that bend the fingers pass from the forearm into the hand, together with one major nerve. The median nerve is a mixed nerve, meaning that it carries fibres conveying sensation and motor fibres which supply muscle, causing movement. The areas served for sensation are the thumb, index, middle and ring fingers on the palm side; the main muscles supplied are those at the base of the thumb that rotate or “oppose” the thumb in front of the rest of the hand.
What is carpal tunnel syndrome?
The carpal tunnel has a fixed volume, and normally the structures within it fit snugly. Any increase in size of the contents, or reduction in size of the tunnel, leads to a rise in pressure, and the nerve is the structure most sensitive to this change. Mild compression of the nerve causes a reduction in sensation in the thumb, index, middle and ring fingers, which is usually intermittent, and recovery of feeling is experienced as pins and needles. Pain is often also a feature, and is felt in the same part of the hand, often radiating up the forearm or even to the shoulder or neck. These symptoms are frequently experienced at night, and waking in the small hours with painful pins and needles is a common presenting symptom. If the compression becomes more severe, numbness may persist, and weakness and wasting of the muscles in the pad of the thumb become noticeable, with reduced ability to oppose the thumb to the fingertips. Loss of pinch together with sensation cause severe functional limitation.
What causes carpal tunnel syndrome?
The most common cause of the condition is a rise in the amount of fluid retained in the body related to hormonal changes. This occurs in early middle-aged women, but it can occur at any age in either sex, though it is rare in children. Fluid retention during pregnancy may precipitate temporary carpal tunnel compression. It can also occur in disorders of fluid balance like thyroid deficiency (myxoedema). It develops in conditions associated with thickening of synovial membranes around tendons, such as rheumatoid arthritis, and sometimes a ganglion or benign growth of fat takes up space in the carpal tunnel, raising the pressure. Anything that distorts the shape of the carpal tunnel can precipitate median nerve compression, such as a fracture of the wrist.
In many cases symptoms resembling carpal tunnel syndrome form part of so-called work-related upper limb disorders, otherwise known as overuse syndrome, or RSI, but great care is needed to establish the true cause of symptoms accurately. Inappropriate surgical decompression can only make matters worse, and may account for poorer results of the operation when a higher proportion of patients with work related disorders have been included.
How is it diagnosed?
The diagnosis can often be made on the basis of your symptoms and signs. However similar symptoms can result from nerve compression higher up the limb, including the neck, and when there is doubt, nerve conduction studies will be carried out. These measure the speed of impulse conduction in the nerve, and the response of the muscles supplied to stimulation.
Can it be treated without an operation?
If the condition is mild, symptomatic treatment may be helpful. These include activity modification (which usually does not give much benefit or has already been tried by the patient), splints and a steroid injection. The splint is mainly worn at night to prevent waking. It stops the wrist from bending down or back too far and so helps protect the nerve from being squeezed at night.
An injection of steroid and local anaesthetic can relieve the symptoms at least in the short-term in most people. Typically the relief from injection is temporary so that most surgeons do not recommend it if the symptoms are marked and established. Nonetheless it can be worth a try especially if there is a self-limiting cause such as pregnancy, but must be expertly done to avoid nerve damage, and in many cases is eventually followed by recurrence. Moreover, in cases where the clinical picture is unclear a positive response to an injection helps confirm the diagnosis. If the steroid helps for a very long time such as > 1 year or for short-term social reasons e.g. an impending exam or wedding then a second injection may be given but rarely more than two.
When do I need surgery?
More severe compression, especially when there is permanently loss of feeling or wasting and weakness of muscles, should be treated by an operation to decompress the nerve.
What is involved in the surgery?
This is done through an incision on the heel of the hand, usually under local anaesthetic, which is briefly painful as is any injection. The arm is painted with an antiseptic to help minimise the risk of infection. The ligament over the nerve is divided, making more room for the contents of the tunnel.
Dissolving stitches are used and a bulky bandage to protect the area.
What can I expect after surgery?
The care of your hand after surgery is very important in helping to ensure a good result. Initially the aims are comfort and elevation. These are met by keeping the hand up especially in the first few days and by use of a long acting local anaesthetic. The local anaesthetic lasts at least 12 hours and sometimes 48 hours. You are encouraged start taking painkillers before the pain starts i.e. on return home and for at least 24 hours from there. This way most patients report little or any pain.
The bandage can be removed after 4 days, leaving a sticky dressing beneath. You are reviewed in clinic between 2-4 weeks following the operation when the sticky dressing is removed. Typically dissolvable stitches are used so removal should not be required. Your hand can be used for normal activity after the first few days.
Most patients can drive after a week or two.
Most patients return to work in 2-3 weeks, but this varies with occupation; heavy manual work usually takes about 6 weeks.
Your wound should be massaged 3 times a day with a bland soft cream for 3 months once the wound is well healed (typically after 2 weeks). This reduces the scar sensitivity which can be a nuisance. If this is marked a Physiotherapy may be organised to help reduce the scar tenderness but this is rarely required. You should avoid pressing heavily on the scar for 3 months following the operation as this will be quite painful. Examples of activities to avoid are using the palm to grip/twist a heavy or tight object or use the palm to help get out of a chair.
What are the results of the operation?
At least 85% of patients in studies say they have a good or excellent result following this operation, with relief of the pain and tingling.
Relief of night waking is usually experienced once the initial operating discomfort has settled.
Most patients have very rapid or immediate relief of their pain. Symptoms of numbness or weakness may well never resolve, particularly if there was continuous numbness or weakness prior to surgery. Nonetheless most patients gain significant benefit in these symptoms which may improve for up to 2 years from surgery.
Full recovery takes one or two months since the scar is often tender at first and strength gradually returns. Function should eventually be normal provided complete release has been carried out. Rarely patients have ongoing symptoms, either due to the diagnosis being wrong, or to an adverse reaction to the surgery.
Patients with conditions that affect nerve function, such as diabetes, tend to get more severe carpal tunnel syndrome and may also fail to recover completely despite full decompression.
Recurrent carpal tunnel syndrome is also rare, but does occur.
Are there any risks?
All operations carry risk, and carpal tunnel surgery is no exception. Saying that, most complications are minor and short lived and do not affect your recovery.
Dr Simcock will go over the risks in more detail prior to surgery.
Is it covered by insurance?
Usually insurance will cover carpal tunnel release.
Dr Simcock is a Southern Cross Affiliated Provider