KIM’S KORNER: Thoracic Outlet Syndrome

Pain, numbness and tingling in the arm can be worrying.  There are many causes of this uncomfortable phenomenon and quite often our first thought is that it could be a sign that there is a problem with the heart; but there are other factors that could be causing the symptoms, one possibility being thoracic outlet syndrome.

Thoracic outlet syndrome (TOS) is a term used to describe symptoms that arise from an area between the collarbone and first rib. TOS can affect the nerves as they come from the spinal cord to the neck and arm. This is known as neurogenic TOS, or it can affect the blood vessels, in which case it’s known as arterial and venous TOS. The majority of cases involving TOS affect the nerves, with about 5% affecting the blood vessels.

The condition is caused by compression of the muscles, nerves and blood vessels in the narrow passage between the collarbone and the first rib and this can cause pain and a range of symptoms. There is not always a known cause of this condition but there are several factors that can lead to symptoms:

• After an injury such as a car accident or a fracture to the collarbone.

• Repetitive stress injuries either through sports like swimming and volleyball or a job that requires lots of movement of the arms.

• Poor posture, especially if the shoulders are extremely rounded.

• Physical defects, some people are born with an extra rib which reduces the space even further.

• Excessive pressure on the upper back, such as carrying a backpack or being overweight.

• Pregnancy, the extra weight can put a strain on the muscles around the collarbone, especially if they are already weak.

Symptoms tend to be exacerbated by movements of the arm, especially lifting the arm up to the side (abduction). The actual symptoms experienced will depend on which structures are under pressure. Nerve pain usually presents with:

• Pain or aching in the neck, shoulder or arm.

• Numbness and tingling in the arm, sometimes all the way down to the fingers.

• Decreased power, especially when trying to grip objects.

If the blood vessels are being constricted the most noticeable symptoms are:

• Discoloration of the hand, usually a bluish or reddish tinge, or paleness.

• Cold hands.

• Pain and swelling in the arm and hand.

• Light pulse.

• Throbbing by the neck.

• Weakness and/or fatigue of the arm and hand.

This is a condition that is more common in people between the ages of 20 and 40, and is seen in women more than men, but is actually a condition that can affect anyone. 

Diagnosis of this condition will depend on the symptoms, but is confirmed by a health-care provider after a thorough examination that will depend on the symptoms. Neurogenic TOS can be hard to diagnose as the symptoms can mimic other conditions such as arthritis, nerve compression, damage to the rotator cuff or carpal tunnel and even conditions like fibromyalgia and multiple sclerosis. Venous and arterial TOS on the other hand is much easier to diagnose due to the changes in skin colour and pulses.

One of the most obvious tests is the reaction of the symptoms when the arms and head are moved into certain positions. An X-ray can also show if there is an extra rib present and also if there is a reduced space between the first rib and collarbone. If it is suspected that the blood vessels are being compromised then an ultrasound scan may be recommended to identify any narrowing or blockages of the blood vessels.

The treatment of TOS will depend on the cause of the symptoms. If the cause is neurogenic then physiotherapy may be recommended for pain management and to give advice on the correct exercises to stretch and strengthen the muscles of the neck, shoulders and upper back and advice on posture and positioning. Medication may also be recommended by a doctor to relax the muscles, reduce swelling and relieve the pain. If the symptoms are due to a compromise of the blood vessels it may be necessary to have a procedure known as TOS decompression. This involves surgery to increase the space so the nerves and blood vessels can pass through more easily.

As always, the best treatment is prevention. Taking a few simple steps may help to avoid this painful condition—stay fit and healthy not only promotes a trim body but also helps to improve posture and prepare the body for added challenges like carrying heavy bags or sitting for hours at a desk.