As recently presented in Rocketfacts. The thoracic outlet is a ring formed by ribs located immediately below the collarbone. Thoracic outlet syndrome (TOS) occurs when nerves or blood vessels are compressed by the rib, collarbone, or neck muscles at the top of the thoracic outlet. Neurogenic TOS is most common. It affects a set of nerves in the spinal cord called the brachial plexus. These nerves control sensations and movement of muscles in the arms, shoulders, and hands. The subcategories in the second type of TOS, venous and arterial, involve compression of veins and arteries each with its own symptoms.
About TOS Risk Factors
Estimates are that up to eighty people out of one thousand may be affected by TOS. Here we list the most common risk factors:
Women are found to be susceptible to TOS as well as males or females between the ages of twenty and forty. Sports such as swimming, golfing, or volleyball that involve repetitive shoulder and arm movement create the likelihood of developing TOS. This risk factor also applies to work that requires heavy lifting as well as strenuous weightlifting. Severe injuries from sports accidents, falls or car accidents may cause compression of thoracic nerves. Doctors advise caution when engaged in high-impact exercises. The same caution is advised with respect to posture while sitting at a computer or worktable. Depression, anxiety, and stress have a negative impact on posture and muscle tone and should also be considered risk factors for TOS.
TOS and Obesity
Excess weight puts pressure and stress on collarbone muscles and joints thereby causing TOS. Doctors for so many reasons advise reaching and maintaining a healthy weight. In the same manner pregnancy causes pressure on joints and deep leg veins. These symptoms often lead to TOS.
TOS and Enlarged Lymph Nodes
This is one of the symptoms that can be misdiagnosed. Enlarged lymph nodes affect the blood vessels and nerves in and around the thoracic outlet.
TOS and Genetic Defects
Birth defects such as tight fibrous bands or cervical rib are sometimes a precursor to TOS.
The following are visible signs of TOS:
- Gilliatt-Sumner Hand: Deterioration of the flesh on the thumb
- Numbness: Tingling and numbness in fingers, arms, or hands
- Weakening Grip: TOS may prevent patients from being able to grip objects and creates problems with dexterity
- Neck and Shoulder Pain: Nerve compression in the spinal cord will travel to the neck and shoulders
- Edema: Swelling in the hands, arms, or fingers possibly due to a blood clot that is interrupting blood flow
- Discoloration: Hands and/or fingers usually turn blue or reddish in color
- Venous TOS is similar to neurogenic TOS with one exception; in venous TOS the tingling in the arm is exceptionally painful.
TOS and Veins
People with venous TOS tend to have prominent veins in the neck, shoulders, and especially in the hands. People who are involved in sports or exercise requiring exceptional physical strength will find their veins more pronounced.
TOS and Blood Circulation
Arterial TOS presents symptoms similar to venous TOS with similar cases of edema and discoloration of hands and fingers.
TOS and Claudication
Arterial TOS involves pain and at times cramping of the forearm caused by sports or any activity that requires overhead motion. For example, these activities include volleyball, basketball, and weightlifting.
TOS and Embolism
Compression of an artery in the arm or hand causing an embolism requires immediate attention. Mayo Clinic describes an embolism as a cramping type of pain, warmth and tenderness to the touch, and a change in skin tone.
The National Institutes of Health and other institutes support TOS research by way of grants to research institutions throughout the nation. The primary focus of the research is to develop improved methods of diagnosis and treatment of TOS.