September 7, 2023 Author : Jorge Pon Carpal tunnel syndrome is the set of signs and symptoms resulting from compression of the median nerve in the area where it passes through the carpal tunnel. It is one of the most common orthopedic problems pf the hand; It is estimated to affect 1%-5% of the population; It is more common in women than in men, with a ratio of about 3:1; It mainly affects the dominant hand, which is probably related to its use. The carpal tunnel and the median nerve The carpal tunnel is a passage in the wrist region : The bony base of this region that forms the transition between the forearm and the hand are the carpal bones; There are 8 carpal bones, arranged in two rows; The walls of the carpal tunnel are 4 of the carpal bones (called pisiform, hamate, scaphoid and trapezium) and a ligament (called transverse ligament or flexor retinaculum); The median nerve and several tendons of the muscles of the hand and forearm pass through the carpal tunnel. The median nerve originates in the spinal cord , enters the upper limb at the armpit and runs until it reaches the palm of the hand after crossing the carpal tunnel. It is mainly responsible for: Sensitivity of the ring (radial half), middle, index and thumb fingers and part of the palm of the hand; Thumb movements and strength. Causes of carpal tunnel syndrome Any circumstance that causes a narrowing of the carpal tunnel can result in compression of the median nerve, for example: Local trauma, with or without fracture or dislocation of the carpal bones; Local cysts or tumors; Edema (swelling) and inflammation of the tendons that pass through the carpal tunnel. Most cases of compression of the median nerve are due to edema of the tendons and occur in people with risk factors that predispose to the development and worsening of the problem over time, for example: Mechanical action, most often associated with repetitive and prolonged use of the hands or fingers and marked flexion and extension of the wrist, such as when using a computer or cell phone; Obesity; Metabolic diseases, such as diabetes; Hormonal imbalances, such as those related to thyroid hormones; Inflammatory diseases, such as rheumatoid arthritis or gout; Fluid retention, as can happen during pregnancy and in many other situations. Symptoms and diagnosis Symptoms of carpal tunnel syndrome and interference with daily activities vary in severity. They are mostly: Pain, numbness, tingling sensation and loss of sensitivity in the middle, index and thumb fingers and in the palm of the hand; Difficulty in movement and lack of strength in the thumb . Initially, symptoms may only be mild, sporadic and in some specific positions, for example, bending the wrist. Numbness at night and tingling sensations in the fingers are the most common. As the problem worsens, there may be decreased sensitivity at the ends of the fingers, inability to coordinate movements and difficulty performing tasks that require the use of the middle, index and thumb fingers, such as grasping an object, particularly if it is small, or write by hand or on a keyboard. In the most serious cases, the difficulty in performing fine motor skills becomes marked, there may be atrophy of the thumb muscles, changes in the shape and position of this finger and inability to use it and even damage to the median nerve. The diagnosis is made based on the history reported by the patient, the signs and symptoms, the physical examination with specific tests carried out at the same time and possibly some exams to support the diagnosis, namely electromyography . Carpal tunnel syndrome treatment The goal of treatment is to eliminate compression of the median nerve . In most cases: Initially, we seek to counter positions associated with symptoms with: Change of activity (if possible); Use of wrist and thumb immobilization devices; Posture corrections and environmental changes; Exercise, application of heat and also taking over-the-counter medications to relieve pain and inflammation may be advised. Local corticosteroid injections are usually the next treatment option, with intervals between treatments and treatment durations to be determined on a case-by-case basis. In many cases, a definitive resolution of the problem is achieved. Surgical decompression of the carpal tunnel to resolve compression is generally reserved for the most severe or recurrent cases: It can be performed through open surgery, with a larger incision, or through small incisions; Requires a period of inactivity of approximately one month; Complete resolution of symptoms may take a few months; May or may not require further rehabilitation with physiotherapy; It has a high success rate, around 90%. Prevention There are no known specific preventive measures for carpal tunnel syndrome. The following may help to avoid or prevent it from worsening : A good posture; Try to keep your wrists unflexed whenever possible; Use of wrist pads for those who spend a lot of time at the computer; Take regular breaks from repetitive manual activities or those involving unnatural prolonged wrist positions, especially in work and sports contexts; Maintain a healthy lifestyle and regular health monitoring; Seek medical attention whenever complaints of pain, numbness or tingling occur in the palms of the hands and middle, index or thumb fingers. Meet the orthopedics clinica team from Hospital da Luz network. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
