Carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is a medical condition due to compression of the median nerve as it travels through the wrist at the carpal tunnel. The main symptoms are pain, numbness and tingling in the thumb, index finger, middle finger and the thumb side of the ring finger. Symptoms typically start gradually and during the night. Pain may extend up the arm. Weak grip strength may occur, and after a long period of time the muscles at the base of the thumb may waste away. In more than half of cases, both sides are affected. Carpal tunnel syndrome (CTS) is a medical condition due to compression of the median nerve as it travels through the wrist at the carpal tunnel. The main symptoms are pain, numbness and tingling in the thumb, index finger, middle finger and the thumb side of the ring finger. Symptoms typically start gradually and during the night. Pain may extend up the arm. Weak grip strength may occur, and after a long period of time the muscles at the base of the thumb may waste away. In more than half of cases, both sides are affected. Risk factors include obesity, repetitive wrist work, pregnancy, genetics, and rheumatoid arthritis. There is tentative evidence that hypothyroidism increases the risk. Diabetes mellitus is weakly associated with CTS. The use of birth control pills does not affect the risk. Types of work that are associated include computer work, work with vibrating tools and work that requires a strong grip. Diagnosis is suspected based on signs, symptoms and specific physical tests and may be confirmed with electrodiagnostic tests. If muscle wasting at the base of the thumb is present, the diagnosis is likely. Being physically active can decrease the risk of developing CTS. Symptoms can be improved by wearing a wrist splint or with corticosteroid injections. Taking NSAIDs or gabapentin does not appear to be useful. Surgery to cut the transverse carpal ligament is effective with better results at a year compared to non-surgical options. Further splinting after surgery is not needed. Evidence does not support magnet therapy. About 5% of people in the United States have carpal tunnel syndrome. It usually begins in adulthood, and women are more commonly affected than men. Up to 33% of people may improve without specific treatment over approximately a year. Carpal tunnel syndrome was first fully described after World War II. People with CTS experience numbness, tingling, or burning sensations in the thumb and fingers, in particular the index and middle fingers and radial half of the ring finger, because these receive their sensory and motor function (muscle control) from the median nerve. Ache and discomfort can possibly be felt more proximally in the forearm or even the upper arm. Less-specific symptoms may include pain in the wrists or hands, loss of grip strength, and loss of manual dexterity. Some suggest that median nerve symptoms can arise from compression at the level of the thoracic outlet or the area where the median nerve passes between the two heads of the pronator teres in the forearm, although this is debated. Numbness and paresthesias in the median nerve distribution are the hallmark neuropathic symptoms (NS) of carpal tunnel entrapment syndrome. Weakness and atrophy of the thumb muscles may occur if the condition remains untreated, because the muscles are not receiving sufficient nerve stimulation. Discomfort is usually worse at night and in the morning. Most cases of CTS are of unknown cause. Carpal tunnel syndrome can be associated with any condition that causes pressure on the median nerve at the wrist. Some common conditions that can lead to CTS include obesity, hypothyroidism, arthritis, diabetes, prediabetes (impaired glucose tolerance), and trauma. Genetics play a role. The use of birth control pills does not affect the risk. Carpal tunnel is a feature of a form of Charcot-Marie-Tooth syndrome type 1 called hereditary neuropathy with susceptibility to pressure palsies. Other causes of this condition include intrinsic factors that exert pressure within the tunnel, and extrinsic factors (pressure exerted from outside the tunnel), which include benign tumors such as lipomas, ganglion, and vascular malformation. Severe carpal tunnel syndrome often is a symptom of transthyretin amyloidosis-associated polyneuropathy and prior carpal tunnel syndrome surgery is very common in individuals who later present with transthyretin amyloid-associated cardiomyopathy, suggesting that transthyretin amyloid deposition may cause carpal tunnel syndrome in these people.