Thoracic Outlet Syndrome

TOS presents with a wide range of symptoms which greatly vary with the nature of compression involved. It has been observed that nerve compression produces more symptoms than when blood vessels are compressed.

When nerve compression occurs, individuals experience pain in the back, neck and shoulders. Development of weakness is a common phenomenon in such cases which eventually leads to weak grip. In addition, affected individuals also complain of tingling sensation and numbness in the 4th and 5th fingers.

Blood vessel compression gives rise to inflammation of the arms accompanied by redness of the affected area. This basically occurs as the blood supply to the affected area is grossly reduced. As a result, the affected arm becomes cool and fatigued.

The following methods are employed to diagnose TOS:

• Physical examination: A detailed medical history along with a thorough physical examination to evaluate the signs and symptoms is carried out. The arms and hands are evaluated in several positions to arrive at a definitive conclusion.
• Elevate arm stress test: In this method, the individuals are asked to raise their arms over the head for about 3 minutes. During this period, they are also asked to alternatively open and close their fists. If symptoms occur during this activity it is an indication of TOS.
• Imaging studies such as CT scan, MRI, ultrasound and x-ray of the bones, blood vessels are carried out to diagnose the condition [7].
• Other tests such as blood circulation tests and nerve conduction tests also form an important part of the diagnostic procedures [8].

Efforts are channelized to treat TOS with conservative treatment at the initial level. If the disease is diagnosed in the preliminary stages then medications and exercises should be employed. Medications such as pain killers and antiinflammatory drugs are prescribed for reducing the swelling and pain. Regular exercising strengthens the muscles and gradually reduces the pressure exerted on the nerves or blood vessels.

Surgery is the treatment of choice if other modes of treatment have failed to yield positive results [9]. Surgical intervention is employed to correct structural deformities or relieve the nerves or blood vessels from the pressure [10].

In majority of the cases, the prognosis is favorable only after surgical procedures to correct the anatomical defects are carried out. In case of physical trauma too, surgery is an effective option. However, there have been instances when patients have reported recurrence of symptoms even after treatment [6].

Compression of the nerves between the collarbone and the first rib is the major cause of TOS. The nerve compression can occur due to the following reasons:

• Physical trauma: Car accidents are one of the major causes of nerve compression. Physical trauma can lead to internal changes that cause the nerves or the blood vessels in the thoracic outlet to get compressed.
• Structural defects: Certain type of congenital defects in the anatomical features can also give rise to nerve compression. Presence of an extra rib or tight fibrous band that connects the spine to rib also causes TOS [3].
• Postural defects: Poor posture habits such as drooping shoulders or keeping the head in forward position can predispose an individual to develop nerve compression.
• Sports: TOS is also thought to be a common phenomenon in athletes who regularly participate in sports that force them to undergo repetitive movements using their arms and shoulders. Such a condition can cause wear and tear of the tissue leading to nerve compression.

The exact incidence of TOS is not known. However, with the available data, it can be estimated that such a type of condition occurs in 3 – 80 cases per 1000 population. TOS is more prevalent in women probably due to poor muscular development, poor posture or anatomical defects in this gender [4].

The thoracic outlet is basically the space between collarbone and first rib. In this space, there are numerous blood vessels, nerves and muscles. In conditions, when the muscles of the shoulder are unable to support the collarbone it may slip from its original position thereby exerting pressure on the nerves, muscles as well as the blood vessels. Such series of events give rise to various symptoms such as pain in the arm, shoulder and neck accompanied by numbness and tingling sensation in the fingers. These are the characteristic features of thoracic outlet syndrome [5].

The onset of TOS cannot be prevented. However the development of debilitating complications can certainly be prevented by following certain simple steps. Individuals experiencing symptoms of TOS are advised to religiously exercise to avoid extra pressure on already compressed nerves. The practice of carrying heavy bags on shoulder should also be discontinued to avoid increase in pressure on the thoracic outlet.

Thoracic outlet syndrome (TOS) is more common in women than men and strikes individuals between 20 to 50 years of age. In addition to the pain in the affected region, the condition can also cause development of tingling sensation in the fingers accompanied by numbness. Physical trauma, repeated injuries, structural abnormalities or physiological conditions such as pregnancy can lead to development of TOS [2].

Definition

Thoracic outlet syndrome (TOS) is characterized by development of pain in the arm, shoulder and neck due to nerve compression in the thoracic outlet. It is a common phenomenon for women and athletes. The age of onset of the disease condition is 20 – 50 years.

Cause

Nerve or blood vessel compression due to repeated pressure on the thoracic outlet is the sole reason for development of TOS. Physical trauma, structural abnormalities or any underlying disease condition causes the nerves to compress giving rise to debilitating symptoms.

Symptoms

Individuals with TOS experience pain in the neck, shoulder and the arms. They also complain of tingling sensation accompanied by numbness in the fingers. In such individuals the arm movement gets limited which makes it pretty difficult to carry out daily tasks.

Diagnosis

Diagnosis of TOS is made after a thorough preliminary physical examination is carried out to carefully study the symptoms reported by the individual. In addition, an elevated stress arm tests is also done to confirm the diagnosis. Imaging studies such as CT scan, MRI, ultrasound and x-ray of the bone are carried out to study the extent of nerve compression.

Treatment

If TOS is diagnosed in the preliminary stages, then conservative approach is enough to treat the condition. Medications and exercises have proven to be beneficial for patients with TOS. However when these fail to show any effect then surgical intervention to relieve the nerve compression is carried out.

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