What is the Carpal Tunnel ?
The Carpal tunnel anatomical tunnel made by the carpal bones of the wrist and a thick ligament at the front, called the flexor retinaculum, or anterior annular carpal ligament.
The carpal tunnel is located at the base of the palm. It contains 9 tendons used to flex the fingers (2 tendons for each long finger and 1 for the thumb). The tunnel also contains the Median nerve,which produces sensations of touch, hot, cold and pain at the base of the thumb, index, middle and half of the ring fingers and at some areas of the dorsal side of these fingers, especially around the nails (see diagram).
Causes of the syndrome
Pressure on the Median nerve causes the symptoms or signals felt by the patient. In most cases, there is not a precise cause. This is called idiopathic carpal tunnel. There are several causes of this syndrome, which produce pressure on the median nerve of the carpal tunnel.
- By far, the most common cause is inflammation of the sheath of tendons inside the carpal tunnel, called synovitis.
- Fractures, trauma and wrist trauma after effects can deform the tunnel.
- Rheumatoid arthritis and other types of chronic rheumatism.
- Tumours, or cysts in the wrist area.
- Some hormonal changes, either temporary such as those occurring during pregnancy, or pathological, such as hypothyroidism (poor performance of the thyroid gland ) and other metabolic diseases.
Potential sufferers of Carpal Tunnel sundrome ?
The carpal tunnel syndrome is generally more common in post menopausal women. However, all adults, men or women, can suffer from an carpal tunnel syndrome. The reasons may vary depending on gender, age, profession, any medical conditions and history of accidents.
Statistically, the syndrome affects the right hand more often than the left, although both can be affected. When Carpal Tunnel Sydrome appears in both hands, it is called bilateral.
Signs and symptoms
The surgeon will ask you about the symptoms you might have :
- Tingling, numbness, or hot and cold in hands, the frequency and intensity of which you will need to describe.
- If you wake up in the night because of pain and numbness in hands. If the numbness and pain disappears after a few minutes shaking or moving you hand.
- A feeling of clumsiness when using your hands, that can make you to drop objects, or prevents you from doing your work.
- Loss of clamping force in your hand.
- Lack of sensation in the tip of one or several fingers.
A diagnosis can be made based on the symptoms described by the patient.Diagnosis is confirmed by clinical tests performed by the doctor, and by additional examinations. The clinical tests will try to provoke the symptoms you describe and measure the pressure on the nerve.
You will be asked to close your wrist for a minute, and describe your sensation. sensitivity of the finger tips is then tested. In some cases, other tests such as blood tests or radiographies will be carried out.
Medical therapy: Medial therapy is effective at the initial stage of the disease, when the nerve has not suffered much damage. Treatment involves the injection of anti-inflammatory drugs inside the carpal tunnel. You will be asked to reduce your activity and, in some cases, you will be prescribed a resting orthesis. You will have to wear it during the night for at least 3 weeks.
The effects of this medical treatment are often only temporary, and further injections are not recommended. In this case, surgery is recommended.
Surgical therapy: Surgery is needed if the pain on the nerve is intense. A consultation with the anaesthetist is necessary before surgery. Carpal Tunnel surgery is a common surgery, and entails no major risk.
The surgical procedure lasts for about 15 minutes and is performed as out patient surgery. This means you will only spend half a day at the hospital.
Surgery involves the sectioning of the ligament which closes the carpal tunnel.
Two techniques are possible: Firstly, conventional open surgery (mini open), and secondly, endoscopic surgery (camera-controlled surgery). The latter is the most recent technique. Both techniques aim to sever this ligament completely.
Post surgery, the arm is supported by a sling for 24 hours. A few months after surgery, the scar is no longer visible..
Dressings are changed until the area is completely healed usually within 2 weeks. . However, after leaving hospital, the hand should be used as much as possible for gentle actions, such as reading, writing and eating. .
Raising the hand and flexing the fingers is recommended to avoid ankylosis.
A 4 week sick leave is prescribed after surgery.
Nerve revovery after surgery
Usually, pain disappears the night after surgery; any tingling sensations can take some weeks or months to disappear. .
In some very serious cases, a low level of sensation might still be present at the end of the recovery period. Strength is recovered gradually over a few months, and in most cases, physiotherapy is not required - using the fingers and wrist after surgery should be sufficient for rehabilitation..
Is surgery always effective ?
Recurrence of Tunnel Syndrome is possible but rare.