Carpal tunnel syndrome (CTS) is a condition in the wrist, in which the median nerve has been pinched. The carpal tunnel is located on the palm side of the wrist. Tendons, nerves and blood vessels are running through this tunnel. In case of overload, a swelling may occur here that, due to lack of space, puts pressure on the nerve causing pain and tingling.
The median nerve (nervus medianus) runs from the forearm through an opening in the carpal bones to the palm of the hand. This opening is called the carpal tunnel. The flexor tendons of the fingers also run through that tunnel. The entrapment of the nerve is caused by swelling of the tissue in and around the carpal tunnel, thereby increasing pressure in the tunnel.
People who have to perform many repetitive movements with hands and wrists, for example in intensive computerwork, are at increased risk of carpal tunnel syndrome. This is probably caused by a local response of strained muscles and tendons and a potentially reduced blood flow at that location. Pregnancy, overweight and diabetes are also risk factors for the development of CTS. Symptoms may also occur at the beginning of the menopause.
The signs and symptoms are often of various kinds:
With physical examination, sensory disorders in thumb, index finger and middle finger can be detected. In particular, a stretch test of the nerve may provoke symptoms. However, often no obvious defects are found and the diagnosis is made on the basis of the symptoms. By means of neurological examination must be ensured that we are dealing with carpal tunnel syndrome. With electromyography (EMG) for muscle examination, the diagnosis can be confirmed. On the EMG, a delay can be seen in the nerve conduction across that portion of the nerve, located in the carpal tunnel.
The treatment depends on the severity, duration, employment conditions and preference of the patient.
For mild symptoms, (temporary) adjustment of the activities of the hand concerned is often enough to make the symptoms disappear. A plastic splint can be put on, allowing rest to the wrist and the symptoms may reduce. Another possibility is to give an injection that dissolves the local swelling of the tendons at the height of the carpal tunnel. Many patients will thus be free of symptoms. Yoga exercises and laser acupuncture may have a beneficial effect in the short term.
In case of prolonged and severe symptoms and when it is certain that the nerve is pinched, the pressure on the nerve can be taken away by surgery. This is a minor procedure, in which an incision is made in the wrist on the palm side. The transverse wristband is thereby severed. This widens the tunnel. Some surgeons perform the procedure as keyhole surgery. Here, the surgeon operates with special instruments that go into the wrist through two small incisions. The advantage is that the incisions are small and therefore leave smaller scars.
Approximately half of the patients whose symptoms are caused during pregnancy, are spontaneously free of symptoms after one year. But also other untreated patients can improve spontaneously, often after a variable course.
Surgery is a good and permanent treatment, which cures ninety percent of the patients. After a surgical procedure, however, the symptoms may return due to the development of scar tissue.
In case of symptoms of carpal tunnel syndrome, it is important that the nerve comes to rest: