The median nerve passes along the base of the palm and the sensory distribution continues to the thumb, to first two fingers and the lateral half of the ring finger. Thus, when this nerve is pressurized, it undergoes dysfunction and the symptoms due to this are mainly tingling sensation along the respective fingers.

Patients also experience numbness and burning sensation which is aggravated during the night [5]. The tingling sensation is noticed more while doing activities such as holding objects or activities involving repeated flexion movements such as type writings etc.

When the condition worsens the patients develop insensitivity, thus they develop inability to differentiate between temperatures over the hand. This is when there is a complete axonal loss leading to absent sensory or motor reflexes. The symptoms in general are activity related and are non-continuous with phases of remission intermittently. Pain is usually associated with numbness. Patients complain of aching sensation along the palm extending to forearm. Loss of muscle power suggests wasting of the muscle leading to clumsiness, loss of grip. Patients complain of objects slipping from the hand [6].

Carpel tunnel syndrome is mainly diagnosed through the presentation and the confirmatory signs that are elicited on the subjects. Sensory examination involves pin prick test that checks bilateral sensation.

• Hoffmann-Tinel test: In this test, gentle tapping is done on the median nerve area, this causes tingling sensation on the palm where the nerve innervates.
• Phalen sign: The wrist is allowed to fully flex, this induces severe tingling along the nerve distribution area.
• In carpal tunnel compression test, a firm pressure is applied over the carpal tunnel directly for about 40 seconds. This results in relapse of all symptoms [7].

However, an MRI scan can be useful to rule out a mass or a lesion occupying the space that compresses the nerve. Ultrasound techniques are now being used along with the nerve conduction studies. These confirm the nerve abnormalities.

Electr physiologic studies enable accurate estimation of the degree of nerve damage thus provides guidance for the prognosis. Certain tests are useful that provide confirmation of CTS.

Symptomatic relief can be achieved through the conservative mode of treatment. This consists of the use of splints on the wrist to be worn at night for a period of at least 3 weeks. Non-steroidal anti-inflammatory drugs for a course of 1-2 weeks help a lot of patients especially with flexor tendinitis or rheumatic arthritis.

Steroidal injections provide a huge amount of symptomatic relief. Surgery is considered when the conservative approach fails [8]. It involves release of the edematous ligament.

A rehabilitation program is highly essential for recovery and strengthening of the affected muscles and ligaments. Aerobic exercise and loosing weight is given prime importance [9].

Carpal tunnel syndrome may lead to lifelong nerve dysfunction. Some cases resolve completely. Surgical treatment prevents recurrence up to 5 years. Conservative treatment may lead to arrest of the further nerve damage.

Patients with obesity or diabetes have poorer prognosis as compared to other healthy subjects. This condition disables the person from doing his daily activities; he is not able to perform simple tasks like carrying objects, or cooking, cleaning etc. Thus it leads to psychological distress [4].

If left untreated, it can lead to progressive wasting of the muscles of hand and ultimately loss of sensation with numbness. It was reported that due to carpal tunnel syndrome, many people were away from their jobs for as long as 27 days in a month.

Although the exact etiology remains unknown, there are many factors that link to the possibility of this syndrome. Systemic illnesses such as hypothyroidism, rheumatoid arthritis, diabetes mellitus are known to trigger carpal tunnel syndrome.

The nerve can also be pressurized due to a local lipoma, a ganglion or a vascular abnormality. Inflammation around the flexor tendons such as tenosynovitis, also compress the nerve and contributes to the carpal tunnel syndrome [2].

People involved in physical labor comprising of continuous and constant hand movements, or having repetitive wrist flexion activities tend to increase pressure at the base of the wrist increasing the risk for carpal tunnel syndrome.

According to the studies conducted in the population of the North American citizens, it was found that the incidence of carpal tunnel syndrome is 1-4:1000. The incidence is common amongst the population involved in manual labor work especially those involved with footwear and clothing industries.

Women are far more affected than males. The incidence increases as age increases. Common age group at risk is between 29-45 years. Individuals with high BMI are commonly affected and the incidence also rises with diseases such as diabetes mellitus, endocrinal and hormonal disorders. It commonly affects women who are pregnant [1].

In carpal tunnel syndrome, symptoms occur due to median nerve dysfunction. This happens as a result of series of changes occurring due to the mechanical pressure on the nerve. It begins with ischemia of the nerve. This is because of the impeded blood flow resulting into blocking of the venous flow, leading to back pressure, and edema [3].

The nerve undergoes demyelination progressing to axonal loss. The amount of pressure that leads to an obstructed blood flow accounts to as low as 20 mm hg. This pressures leads to capillary breakage, edema in and around the nerve and persistent rise in the pressure on the nerve.

Preventive measures involve maintaining a healthy weight which helps in preventing diabetes, arthritis and other diseases. Exercising regularly and avoiding smoking are important. People involved in cash collecting jobs should avoid forceful wrist movements while opening the drawers with keys. People who are involved in type writing work should change the set up of their desks and computers according to convenience. The level of the wrist should be at the level of the elbow or slightly higher.

Breaks from continuous activities are advised to relax and stretch the tensed muscles. Stiffness and pain is more if the environment is cold and hence the temperature should be adjusted or if that is not possible, woolen gloves are to be worn to keep the wrist and palms warm. For writers, a large pen with a soft grip is advised so as to relieve the pressure of the fingers due to tight grip [10].

The carpal tunnel is a narrow tunnel or a canal on the distal area of the wrist at its base. It connects the forearm to the wrist and in this tunnel several muscular tendons along with median nerve pass through.

The compression or the entrapment of this median nerve is called as the carpal tunnel syndrome (CTS). The inflammation of the tissues surrounding the tendons increases the pressure within the canal thus pressing the nerve. Carpal tunnel syndrome comprises of symptoms following this compression [1].

Carpal tunnel syndrome is a syndrome consisting of multiple symptoms due to pressure on the medial nerve in the wrist. The medial nerve passes along the carpel tunnel at the base of the wrist joint. Many muscles, ligaments along with the median nerve pass through the canal.

When this nerve is compressed it results in sensory loss, tingling, numbness, pain, stiffness and aching of the affected hand. The causes are local and systemic. The local causes include compression of the nerve due to excessive and forceful wrist movements commonly seen in those involved in repeated hand movements like typewriting, food packers, foot making laborers etc. local tumors or tendinitis also increase the pressure in the canal leading to pinching of the nerve. Systemic causes are diseases such as diabetes or arthritis.

Treatment consists of pain killers and anti-inflammatory drugs. Surgery is done if pain is severe and not responding to medications. Prevention is done by regular exercise, weight loss, stretching and taking breaks from constant activity [11].

1. Atroshi I, Gummesson C, Johnsson R, Ornstein E et al. Prevalence of carpal tunnel syndrome in a general population. JAMA. 1999 Jul 14;282(2):153-8.
2. Werner RA, Andary M. Carpal tunnel syndrome: pathophysiology and clinical neurophysiology. Clin Neurophysiol. 2002 Sep;113(9):1373-81.
3. Cellocco P, Rossi C, Boustany SE, di Tanna GL, Costanzo G. Minimally invasive carpal tunnel release. Orhtop Clin North Am. 2009 Oct;40(4):441-448.
4. Middelkoop M, Koes BW. Carpal tunnel syndrome. Part I: Effectiveness of nonsurgical treatments -- a systematic review. Arch Phys Med Rehabil. 2010 Jul;91(7):981-1004.
5. Huisstede BM, Randsdorp MS, Coert JH, Glerum S, et al. Carpal tunnel syndrome. Part II: effectiveness of surgical treatments -- a systematic review. Arch Phys Med Rehabil. 2010 Jul;91(7):1005-1024
6. Jarvik JG, Comstock BA, Kliot M, Turner JA, et al. Surgery versus non-surgical therapy for carpal tunnel syndrome: a randomized parallel-group trial. Lancet. 2009 Sep 26;374(9695):1074-1081.
7. LaStayo P, Mills A, Bramlet D. Prospective analysis of splinting the first carpometacarpal joint: an objective, subjective, and radiographic assessment. J Hand Ther. 2000 Jul- Sep;13(3):218-226
8. Wilson KM. Double incision open technique for carpal tunnel release: an alternative to endoscopic release. J Hand Surg Am. 1994 Nov;19(6):907-912.
9. Wilson J. Median mixed nerve conduction studies in the forearm: evidence against retrograde demyelination in carpal tunnel syndrome. J Clin Neurophysiol. 1998 Nov; 15(6):541-46.
10. Wong SM, Griffith JF, Hui AC, Tang A,et al. Discriminatory sonographic criteria for the diagnosis of carpal tunnel syndrome. Arthritis Rheum. 2002 Jul; 46(7): 1914-21.
11. Wiederien R, Feldman TD, herusel LD, Loro WA et al. The effect of the median nerve compression test on median nerve conduction across the carpal tunnel. Electromyogr Clin Neurophysiol. 2002 Oct-Nov; 42(7): 413-21