Carpal Tunnel Syndrome is also known as median neuropathy as it involves the median nerve of the upper limb. It occurs due to compression of the median nerve when it passes through the "carpal tunnel" in the wrist. Carpal Tunnel Syndrome is the most common "entrapment neuropathy".
Carpal tunnel syndrome occurs more frequently in people whose job involves use of hands and wrists. A common cause is typing on a computer keyboards for many hours over a long period of time. It may also be caused due to other works like painting, writing, sewing, use of hand tools especially vibrating tools, sports like handball and tennis. Another cause may be forms of arthritis, autoimmune diseases like systemic sclerosis, systemic lupus erythematosus, excess growth hormone in body, obesity, dialysis etc.
Carpal tunnel syndrome often presents with pain, tingling or numbness in thumb, index finger, middle finger and half of the ring finger and parts of the palm below these fingers. Pain and paresthesias sometimes may extend up to the elbow or even in upper arm. The symptoms are often worse at night. Also there may be complaints of weakness like weak grip or trouble in carrying bags and fine movements of finger. In severe forms, there may be even wasting of the muscles at the base of the thumb (called "thenar muscles").
Treatment of this neuropathy depends on the cause. Treatment is often necessary as untreated Carpal Tunnel Syndrome may result in permanent damage to median nerve distal to carpal tunnel and resulting in permanent symptoms not amenable to therapy. If Carpal Tunnel Syndrome occurs secondary to some other medical disorder, treating it often reverses the carpal tunnel syndrome. For example, in hypothyroid patients, treatment with levothyroxine often results in alleviation of symptoms of carpal tunnel. Similarly treatment of Rheumatoid arthritis with immunomodulator drugs often relieves the problem.
If the problem is due to improper pattern of hand use, then the treatment is mainly giving rest to the wrist by avoiding the precipitating factors. Neutral Position wrist splints are often tried. Patient may be given NSAID (like Iburprofen) for pain, and in severe cases, steroid injection in wrist may also be given. Local steroid injection reduces the swelling and thus eases the pressure on the nerve. Similarly anesthetic injection may be given to alleviate pain.
Surgery is done if the medical treatment fails to alleviate the symptoms and the problem persists or if patient presents with wasting/weakness of the thenar muscles of the hand. In surgery, the transverse carpal ligament is divided to enlarge the tunnel and create more room for the nerve. Surgery is often successful, but in certain cases it may not completely alleviate the symptoms if the compression has been severe and prolonged and permanent damage to nerve has occurred.