Thoracic Outlet Syndrome

What is thoracic outlet syndrome?

Thoracic outlet syndrome (TOS) is the general term used to describe a condition caused when the nerves and blood vessels below your neck (between the collarbone and the first rib) are compressed. Types of thoracic outlet syndrome include:

• context Neurogenic (neurological) thoracic outlet syndrome - occurs when the brachial plexus is compressed. The brachial plexus is a group of nerves that come from the spinal cord and control muscle movements and sensations in the shoulder, arm, and hand.
• context Vascular thoracic outlet syndrome - occurs when one or more of the blood vessels (veins or arteries) under the collarbone are compressed.
• context Nonspecific-type thoracic outlet syndrome - people with this syndrome have chronic pain in the area of the thoracic outlet that worsens with activity, but a specific cause of the pain cannot be determined.

What are the occupational factors of thoracic outlet syndrome?

• context Work activities involving prolonged restricted postures, such as carrying heavy shoulder loads, pulling shoulders back and down, or reaching above shoulder level, can cause inflammation and swelling of tendons and muscles in the shoulders and upper arms. When swollen or inflamed, they can compress the nerves and blood vessels between the neck and shoulders. Weak shoulder muscles, long necks and sloped shoulders, poor posture and obesity may contribute to thoracic outlet syndrome. Repetitive injuries from sports-related activities can also be a cause of this syndrome. Examples of occupations that are at risk of this syndrome can include dental hygienists, typing on a computer, working on an assembly line, or lifting items above your head.

What are the general causes of thoracic outlet syndrome?

The cause of the compression can vary but include: Slightly more women than men may develop this syndrome. It is more common in young adults between 20 and 40 years old.

• context Poor posture - drooping shoulders or holding the head in a forward position.
• context Trauma - Trauma, such as from a car accident.
• context Anatomical defects - how your body is formed at birth may include an extra rib located above the first rib or an abnormally tight fibrous band that connects the spine to the rib.
• context Pressure on joints - obesity and carrying an oversized bag or backpack can put an undue amount of stress on joints.
• context Pregnancy - as joints loosen during pregnancy, signs of thoracic outlet syndrome can appear.

What are the symptoms of thoracic outlet syndrome?

Depending on which structures are compressed, symptoms can vary. When nerves are compressed, symptoms of neurological thoracic outlet syndrome can include: Signs and symptoms of vascular thoracic outlet syndrome can include:

• context Numbness or tingling in the arms or fingers
• context Muscle wasting in the fleshy base of the thumb
• context Pain or aches in the neck, shoulder, or hand
• context Weakness in your hand grip strength
• context Numbness or tingling in fingers
• context Discoloration of hand (bluish colour)
• context Blood clots in veins or arteries in the upper area of the body
• context Throbbing lump near the collarbone
• context Cold fingers, hands or arms
• context Arm pain and swelling
• context Weak or no pulse in the affected arm

How is thoracic outlet syndrome recognized?

• context The diagnosis is made by medical history and physical examination. Special laboratory tests can confirm the diagnosis.

How is thoracic outlet syndrome treated?

• context The initial treatment of patients with thoracic outlet syndrome consists primarily of a carefully planned program of exercise therapy. Avoidance of work activities suspected of causing the condition may be necessary. Physicians may prescribe anti-inflammatory drugs to reduce the pain and inflammation. In some cases, surgery may be necessary if symptoms persist for a long time.