What is Carpal Tunnel Syndrome? Before recognizing carpal tunnel syndrome, let us first understand the anatomy of the carpal tunnel. The carpal tunnel consists of a “U”-shaped arrangement of carpal bones surrounded by the transverse carpal ligament (Figure 1). It is a fibrocartilaginous canal that is bony on three sides and ligamentous on the other. Within this canal, there is one median nerve and nine flexor tendons. The median nerve is located below the transverse carpal ligament, superficial to the flexor tendons, and, after crossing the carpal tunnel, innervates sensation in the three and a half fingers on the radial side (thumb, digit, middle finger, and radial side of the ring finger) as well as the greater trochanteric muscles. Any cause that results in a decrease in carpal tunnel volume or an increase in the contents of the carpal tunnel can increase pressure within the carpal tunnel, squeezing and provoking the median nerve. The signs and symptoms caused by pressure on the median nerve in the carpal tunnel are called carpal tunnel syndrome. What causes carpal tunnel syndrome? 1. Any factor that can cause the volume of the contents of the carpal tunnel to increase or the volume of the carpal tunnel to decrease can compress the median nerve and cause symptoms. 2. Repeated manual labor, especially repeated pinching and grasping movements in the flexed wrist position, and repeated flexion and extension of the tendons of the hand, causing swelling and hyperplasia of the synovium of the flexor tendons, can lead to carpal tunnel syndrome. Jobs with this risk factor include operating computers, carpentry, work on assembly lines, food packaging, playing musical instruments, machine operation and repair. Personal hobbies such as gardening, needlework, and golfing can also sometimes cause symptoms. 3, women are more prone to the disease than men, before and after menopause and pregnant women due to changes in hormone levels in the body, stimulating the tendon synovial membrane hyperplasia, so that the contents of the carpal tunnel increased, resulting in an increase in the pressure in the carpal tunnel and compression of the median nerve. Pregnant women are also prone to develop the disease. 4, wrist injury can also cause carpal tunnel syndrome. Such as distal radius fracture, due to fracture displacement, resulting in narrowing of the carpal tunnel, while traumatic synovitis caused by trauma, resulting in an increase in the contents of the carpal tunnel, which can easily cause carpal tunnel syndrome. 5, some diseases, such as obesity, hypothyroidism, diabetes mellitus, rheumatoid arthritis, etc., also easy to cause carpal tunnel syndrome. Carpal tunnel swelling, such as tendon sheath cysts, lipomas, displaced muscles, etc. can also cause this disease. What are the clinical manifestations of Carpal Tunnel Syndrome? Patients with Carpal Tunnel Syndrome begin to experience numbness and tingling in the three and a half fingers on the radial side (thumb, thumb, middle finger and radial half of the ring finger). This sensation is particularly noticeable at night and often wakes the patient up with numbness, which can be relieved by shaking the hand, squeezing and clenching the hand or making a fist repeatedly, thus interfering with sleep. The numbness and tingling sensation is most obvious in the middle finger, and some patients consult the doctor only for numbness in the middle finger. As the disease progresses, patients feel dull pain, cramps and weakness in the hand, and often fall to the ground when holding objects. Some patients gradually feel atrophy of the interosseous muscle (as shown below) and weakness of the thumb against the palm. Some patients may also have no sensory deficits and present simply with atrophy of the piriformis muscle. How is carpal tunnel syndrome diagnosed? Diagnosis is not difficult based on clinical presentation and examination. The diagnosis of carpal tunnel syndrome should be highly suspected if the patient has nighttime numbness and pain that interferes with sleep, and if the sensory disturbance is limited to the three and a half fingers on the radial side. Physical examination reveals that the area of sensory disturbance is limited to the three and a half fingers on the radial side; if the muscles of the hand are atrophied, it is limited to the greater trochanter; percussion of the transverse carpal ligament often induces radicular pain radiating to the middle finger (Tinel’s sign positive); flexion of the wrists at 90 degrees for one minute often worsens the numbness on the affected side and radiates to the middle finger (Phalen’s sign positive); and the pain on the affected side often worsens and radiates to the middle finger (Phalen’s sign positive). A compression of the transverse carpal ligament for 1 minute may also induce similar symptoms. Laboratory tests are mainly electrophysiologic, and nerve conduction velocities that are markedly prolonged in the carpal segment strongly suggest compression of the median nerve in the carpal tunnel. Differential diagnosis must examine the neck and shoulders as well as nerve reflexes to exclude cervical spondylosis. Especially in computer operators, carpal tunnel syndrome is often combined with neck and shoulder pain due to prolonged seated work, and nerve compression due to cervical spondylosis should be excluded. In a few cases, nerve compression caused by cervical spondylosis can also cause symptoms similar to carpal tunnel syndrome, but the scope of nerve involvement is extensive, and neck and shoulder activities often induce top-down radiating pain, and the area of sensory impairment and muscle involvement is not limited to the median nerve, which is not difficult to distinguish by careful clinical examination. How to relieve after the onset of the disease? 1, Sleeping can use pillows to elevate the affected forearm; 2, Use the normal hand more often, avoid excessive use of the affected hand; 3, Use different tools, try to change the way of using the hand; 4, Avoid prolonged hanging wrist posture. How is it treated? The choice of treatment depends on the severity of the symptoms and the underlying condition causing carpal tunnel syndrome. Conservative treatment can be used for those with mild symptoms, including wrist rest, immobilization with braces, physiotherapy and intracarpal tunnel closure therapy, and can be supplemented by blood-activating and blood-stasis-relieving herbal infusions. Medication includes oral neurotrophic drugs such as methylcobalamin, which can help nerve repair, and non-steroidal anti-inflammatory drugs, which can inhibit local inflammatory reaction and analgesia. Adjustment of work style For symptoms caused by overuse of the hands, appropriate adjustments should be made to the work style, such as adjusting the keyboard and seat height for computer operators; taking regular breaks at work and performing passive wrist stretching exercises. Surgical treatment It is generally recognized that patients over 50 years of age with persistent unrelieved symptoms, associated with proliferative synovitis of the flexor tendons or atrophy of the interosseous muscles should be operated on as early as possible. Surgery to release the transverse carpal ligament usually results in rapid relief of pain symptoms, but recovery of sensory function and muscle atrophy takes longer. How to prevent? In daily work and life, paying attention to the following points can help prevent carpal tunnel syndrome: 1. If you need to repeat a certain movement of your hands for a long time at work (e.g. typing, needlework), stop often and give your hands a rest. 2. Don’t keep your hands too close or too far away from your body while working. 3.Don’t work with your hands on the surface of hard objects for a long time. 4. Squeeze, stretch or shake your hands frequently while working. 5.Work with tools that are not too large for the hands. 6, do not stand in the same position all day or sit for a long time. 7, if you have to use the keyboard for a long time, you should adjust the seat height, so that the forearms and the keyboard at the same height, to avoid dropping the wrist to hit the keyboard. 8. Actively treat diseases that may be secondary to carpal tunnel syndrome. If you are overweight, you should lose weight.