Carpal Tunnel Syndrome (CTS) is a common problem that affects the hand and wrist. Symptoms begin to appear when the median nerve gets compressed inside the carpal tunnel of the wrist. This medical condition is referred to as ‘nerve compression”. Any condition decreasing the volume of the carpal tunnel or increasing the size o the tissues inside the carpal tunnel can produce the symptoms of carpal tunnel syndrome.
The median nerve passes through the carpal tunnel and reached the hand. It gives sensation to the thumb, index finger, long finger, and half of the ring finger. It also gives a nerve branch for the control of the thenar muscles in the thumb. The thenar muscles enable the thumb to perform the motion called ‘opposition’. The motion that involves making the pad of the thumb touch the tips of other fingers is called opposition.
What are Its Symptoms?
They are tingling and numbness in the hand and fingers, especially when using the hands.
What are Its Causes?
Any condition decreasing the volume of the carpal tunnel or increasing the size o the tissues inside the carpal tunnel can produce the symptoms of CTS. For example, a wrist trauma may cause swelling and an increase in the internal pressure of the carpal tunnel. The space inside the carpal tunnel may be reduced when a bone tissue is pushed into the tunnel, in case of a wrist fracture or dislocation.
Various types of arthritis may cause swelling and an increase in the internal pressure of the carpal tunnel. After wrist fractures, healed bone fragments may later lead to CTS formation, due to the resultant abnormal irritation on the flexor tendons caused by those fragments.
Many conditions in our body may produce symptoms of CTS. During pregnancy period, excessive fluid retention may lead to an increase in the internal pressure of the carpal tunnel; and this condition may result in CTS development. In diabetics, neuropathy or the pressure on the median nerve may cause the symptoms of CTS. Hypothyroid patients are prone to CTS problems.
In some cases, CTS may develop due to thickening of the tenosynovium resulted from irritation or inflammation. This thickening causes an increase in the internal pressure of the carpal tunnel. Since the carpal tunnel cannot get larger in response to the increased swelling, the median nerve begins to be squeezed against the transverse carpal ligament. If the pressure keeps increasing, the nerve cannot function fully.
With the increase in the pressure on the median nerve, the blood supply to the nerve membrane slows down, and may even completely stops. This condition is referred to as ‘ischemia’. First, the outer layer of the nerve is affected. But in the course of time, the inside of the nerve gets thickened. New cells (fibroblasts) form in the nerve, and they produce scar tissue. This tissue is thought to be the cause of the pain and numbness in the hand. If the pressure is eliminated, the symptoms will go away quickly. If the pressure is not reduced, even the chance for recovery will not be available in the following period.
What are the Clinical Symptoms of the Disease?
It shows itself with the sensations of tingling, numbness, burning, etc. especially in the thumb, index finger, middle finger, and half of the ring finger facing the middle finger.
Certain complaints such as a relatively less pain in the wrist and a decrease in the grip strength can also be identified. A slight pain in the region and nightly pain in the course of time can be seen.
Pain sometimes spreads to the arm or shoulder. As the syndrome progresses, weakness occurs in the thenar muscles. Especially weakness is felt while holding a glass. . If the internal pressure of the carpal tunnel keeps increasing, atrophy develops in the thenar muscles. It becomes difficult to make the pad of the thumb touch the tips of other fingers. It becomes difficult to hold a telephone and newspaper.
How to Diagnose the Disease?
Although the symptoms of the patient and findings obtained from medical examination are adequate for a physician to diagnose carpal tunnel syndrome, there are certain tests used to support the diagnosis.
Most hand surgeons combine symptoms, the above-mentioned clinical findings, and the results of electrophysiological tests (EMG), with intent to confirm the diagnosis
Electrophysiological tests: They are electromyography and studies on. They can numerically show a median nerve dysfunction and nerve conduction velocity by comparing the nerve with other nerves.
Phalen’s maneuver: The patient flexes the wrists inwards to a 90-degree position, and then the initiation of the symptoms are waited for.
Tinel’s sign test: The doctor taps on the inside of the wrist, with his finger tip, and then waits for the development of tingling sensation in the areas, where the nerve receive its sensation.
Durkan’s test: The doctor firmly presses on the nerve in the palm for 30 seconds, and waits for the exacerbation of the symptoms.
Description of the symptoms by the patient and physical examination are the most important parts in the diagnosis. Patients usually complain of a pain that awaken them from sleep at night as well as the feeling of numbness in their hands. Numbness felt when driving a car and using a hammer or broom is among other complaints.
If your symptoms have begun after a trauma, an x-ray is taken to exclude the possibility of any broken wrist bone. If more information is needed for diagnosis, the doctor can request certain tests, which are based on the measurement of nerve conduction velocity in the wrist. With this test called ‘EMG’, the median nerve function and nerve conduction velocity are measured.
What are the Treatment Variations of the Disease ?
Activities that lead to symptoms need to be changed or stopped if possible. Lifting heavy things, doing repetitive motions, using devices that cause exposure to vibration, and working constantly with the wrist bent down should be avoided. Smoking should be stopped, caffeine intake should be reduced, and excessive weight should be lost.
Using a wrist splints at early stages of carpal tunnel syndrome can sometimes reduce symptoms. A splint keeps the wrist in a resting position. It prevents the wrist from bending backward or downward excessively. Keeping the wrist in this position provides the widest possible space for the median nerve in the carpal tunnel. Since a splint prevents the writs from bending especially at night, it is useful in terms of reducing the pain and numbness felt at night. Splint can also be used in the daytime, with intent to alleviate the symptoms and enable the structures in the carpal tunnel to relax.
Anti-inflammatory medications can be helpful in alleviating the carpal tunnel symptoms, and reducing edema. Ibuprofen and aspirin can be used for this purpose. In some studies, high-dose Vitamin B-6 has been found to be effective in alleviating the symptoms. Likewise, exercise has been shown to be useful in reducing the CTS symptoms.
If other procedures intended for reducing the symptoms fail, surgery may be recommended for reducing the pressure on the median nerve. With the reduction of the pressure on the nerve, blood supply to the nerve increases, and patients get rid of the symptoms. However, if the nerve compression has lasted for a long time, thickening and scar tissue development occur in the nerve. In such a case, postoperative recovery will be slow.
The standard surgical procedure for the treatment of CTS is open carpal tunnel release. An approximately 5 cm incision extending from the wrist to the palm is made. Surgeon cuts the transverse carpal ligament to reduce pressure on the median nerve. Meanwhile, it is clearly seen that the median nerve tissue is relieved of the pressure. Then the skin is sutured by leaving the two cut ends of the transverse carpal ligament separated. Thus, the pressure on the median nerve is removed. In course of time, a scar tissue develops between these two ends.