Thoracic Outlet Syndrome (TOS)

Thoracic outlet syndrome (TOS) is a medical condition that involves compression, injury, or irritation of the nerves and/or blood vessels (arteries and veins) in the thoracic outlet area, which is the space between your collarbone (clavicle) and first rib. This can cause pain in your shoulders and neck and numbness in your fingers.

Causes and Risk Factors

TOS can be caused by a variety of factors, including:

• Anatomical abnormalities: Such as an extra rib or an abnormal first rib, which can compress the nerves and blood vessels in the thoracic outlet area.
• Repetitive motion or overuse: Activities that involve repetitive movements of the arm, such as swimming, baseball pitching, or computer work, can cause TOS.
• Trauma: A fall or a car accident can cause injury to the nerves and blood vessels in the thoracic outlet area, leading to TOS.
• Poor posture: Slouching or having poor posture can put pressure on the nerves and blood vessels in the thoracic outlet area, contributing to TOS.
• Weightlifting or heavy lifting: Lifting heavy weights or objects can cause strain on the muscles and nerves in the thoracic outlet area, leading to TOS.

Symptoms

The symptoms of TOS can vary depending on whether the compression involves the nerves (neurogenic TOS) or blood vessels (vascular TOS). Common symptoms include:

• Pain or aching: In the shoulders, neck, and upper back.
• Numbness or tingling: In the fingers or hands.
• Weakness: In the arms or hands.
• Coldness or paleness: Of the hands or fingers (in cases of vascular TOS).
• Fatigue: In the arms or hands.
• Swollen or blue-tinged hands: (in cases of vascular TOS).

Diagnosis

TOS can be diagnosed through a combination of:

• Medical history: A thorough medical history to identify any underlying conditions or activities that may have contributed to the development of TOS.
• Physical examination: A physical examination to assess muscle strength, sensation, and reflexes in the affected area.
• Imaging tests: Such as X-rays, computed tomography (CT) scans, or magnetic resonance imaging (MRI) scans to rule out other conditions and confirm the diagnosis of TOS.
• Nerve conduction studies: To assess nerve function and identify any abnormalities.
• Angiography: To evaluate blood flow in the affected area (in cases of vascular TOS).

Treatment

Treatment for TOS typically involves a combination of:

• Physical therapy: To improve posture, strengthen muscles, and increase range of motion.
• Pain management: With medications such as pain relievers or muscle relaxants.
• Lifestyle modifications: Such as avoiding repetitive activities, taking regular breaks, and improving posture.
• Surgery: In some cases, surgery may be necessary to relieve compression on the nerves or blood vessels.

Complications

If left untreated, TOS can lead to:

• Chronic pain: Persistent and debilitating pain in the shoulders, neck, and upper back.
• Nerve damage: Permanent nerve damage or numbness in the hands or fingers.
• Blood vessel damage: Damage to the blood vessels, which can lead to circulatory problems or even gangrene (in severe cases of vascular TOS).