Carpal tunnel syndrome is a characteristic set of symptoms which are caused by increased pressure on the major nerve supplying sensation to the hand at the level of the wrist. This nerve is called the median nerve.
The classic carpal tunnel syndrome symptoms are pain at the wrist which may extend back up the arm and numbness on the front of the thumb, index, middle and half of the ring fingers. Sometimes numbness is made worse by activities such as holding the steering wheel of the car or holding the telephone. Often people report feeling like their hand is clumsy and they may report dropping objects. In severe or longstanding cases you may notice wasting of the muscles at the base of your thumb.
Waking up from sleep with pain and numbness in the hand and forearm is a classic symptom of carpal tunnel syndrome.
In the majority of people the cause of carpal tunnel syndrome is unknown. Sometimes there may be a history of a fracture of the wrist, swelling of the lining tissues around the flexor tendons (such as may be seen in rheumatoid arthritis).
Carpal tunnel syndrome is quite common in the later stages of pregnancy when expectant mothers tend to retain a significant amount of extra fluid. It tends to resolve after the baby has been born and the fluid resolves but this is not always the case.
For reasons which are not fully understood carpal tunnel syndrome is more commonly seen in people who have diabetes. Similarly under activity of the thyroid might contribute to developing carpal tunnel syndrome symptoms.
Diagnosis: The diagnosis of Carpal tunnel syndrome is most often made on the symptoms and signs visible on physical examination. The diagnosis may be confirmed by nerve tests (often called nerve conduction studies) which test how quickly nerve impulses travel down up the median nerve across the wrist. The test is looking for any evidence of delay of these nerve impulses.
Non operative treatments:
1. Splints often resolve the symptoms of CTS. The splint are worn at night and hold your fingers out straight ( so they cannot flex) this increases the space within the wrist and prevents pressure building up on the median nerve. Some people can make splints work for them but the majority of people find them impractical. If you imagine having table tennis bats strapped onto the front of your hands or hands overnight then it becomes obvious even simple tasks like pressing the button on the alarm clock or getting up to go the bathroom becoming major undertakings. This is even more difficult if you have CTS in both hands or you live on your own.
2. Steroid injections. Steroids are anti inflammatory and can temporarily reduce the fluid and tissue swelling around the median nerve. Steroid injections are therefore useful if you think the cause to CTS is likely to resolve in the near future. The major indication for steroid injections therefore is pregnancy. Steroid injections are usually used in combination with night splints.
3. Surgery for CTS is performed commonly. There are 2 commonly performed techniques. Open carpal tunnel surgery and endoscopic carpal tunnel surgery. The techniques differ in the position of the incisions and instruments used but they both achieve the same basic task which is to divide a thick, non elastic band of tissue called the flexor retinaculum. Dividing this band of tissue creates more space for the median nerve to exist in releasing the pressure on the nerve.
Carpal tunnel surgery is normally performed as day procedure at the hospital. Usually the surgery is performed under local anaesthetic with intravenous sedation. You will not remember the procedure.
Commonly after surgery patient report weakness of grip strength which takes weeks to resolve . There can be tenderness in the proximal palm ( called pillar pain) where the band has been divided this settls with time and massage.
Numbness may settle quickly if the symptoms have only been present for a short period ( months) but may take a very long time ( 12 -18 months) to resolve or never resolve if the nerve has been permanently damaged by pressure which has been present for years before treatment has been sought.