Reviewed by Brian R. Robinson, MDThoracic outlet syndrome (TOS) is a compression of the blood vessels or nerves located in the thoracic area of the body, which is the area behind the collar bone. TOS is a cumulative trauma or repetitive stress disorder that can be aggravated by repetitive motion, such as typing on a keyboard, assembly line work or stocking shelves overhead.
TOS develops when a neurovascular bundle (a tight network of nerves and veins) in the chest suffers an abnormal compression or, in the case of repetitive stress injuries, a series of abnormal compressions, by bone, muscle, or connective tissue in the area. TOS is usually caused by hyperextension neck injuries, such as whiplash or repetitive stress that exert pressure against the blood supply or nerves leading to the arms. In a small percentage of cases, TOS results from an extra rib in the neck, called a cervical rib. People with cervical ribs are ten times more likely to suffer from TOS than people without them.
The most common symptom of TOS is pain and tingling in the arm, shoulder, and hands. Other symptoms may include:
• swelling or puffiness in the arm or hand
• bluish discoloration of the hand
• the presence of a lump above the clavicle
• pain in the neck and shoulder which increases at night
• easily fatigued arms and hands
• superficial vein distention in the hand
• weakness of grip or loss of sensation in arm, hand or fingers
• difficulty moving shoulder, arm, hand, or fingers due to numbness and weakness
TOS can be diagnosed with the application of several tests of mobility and sensation in the area, as well as an examination of the area for physical abnormalities. Attention to case history, such as whether the patient engages in repetitive, heavy lifting or other activity that could cause a repetitive stress injury, or whether the patient has recently suffered an injury that can lead to TOS, can also be of help in diagnosis.
Most cases of TOS are resolved through rehabilitative therapy and exercise. A doctor or physical therapist can help to correct postural abnormalities that contribute to compression and establish an exercise program to strengthen the shoulder muscles and stretch the neck muscles.If vascular impairment (cutting off of circulation to the area) is present, your doctor may recommend surgical decompression. Most TOS sufferers recover via non-surgical methods.
