The thoracic outlet is the space between the lower neck and upper chest. Thoracic outlet syndrome (TOS) consists of a group of disorders that occur when the nerves and/or blood vessels of the thoracic outlet become compressed and irritated causing pain in the shoulder, neck and arm. This compression occurs between the collarbone and first rib or between the muscles of your neck and shoulder.
CAUSES
An extra cervical rib or fractured collarbone can reduce the space available for nerves and blood vessels, resulting in thoracic outlet syndrome. Factors that may increase risk of developing thoracic outlet syndrome include:
- Stress
- Depression
- Poor posture
- Sleep disorders
- Traumatic event, such as a car accident
- Injury to neck or back
- Lifting heavy weights
- Repetitive injuries from carrying a heavy load
- Tumors or large lymph nodes in underarm area or upper chest
- Pregnancy
- Repetitive shoulder or arm movement from sports, such as baseball, golf, swimming and others
Thoracic outlet syndrome can affect men or women of any age from 20 to 80. However, TOS occurs more frequently in women around 40 years of age.
TYPES OF THORACIC OUTLET SYNDROME
- Neurogenic thoracic outlet syndrome is characterized by the compression of the brachial plexus – the system of nerves that control motor and sensory movements to the hand, shoulder and arms. Symptoms often include numbness or weakness of the hand, tingling, pain or a prickling feeling in the arms, chest and neck. Most symptoms of thoracic outlet syndrome are neurogenic. Neurogenic thoracic outlet syndrome is the most common type of TOS, making up 96 percent of TOS diagnoses.
- Venous thoracic outlet syndrome is a result of damage to major veins in the upper chest and lower neck region. This type of TOS develops unexpectedly, typically occurring immediately after rigorous exercise of the arms. Symptoms may include heaviness and weakness of the arms and neck, and swelling of the arms, hands and fingers. Veins at the front of the chest may look swollen.
- Arterial thoracic outlet syndrome is the least common type of TOS, but is the most serious. The subclavian artery – the main artery to the arm – either becomes enlarged, forming an aneurysm and a blood clot in the wall of the artery, or, the artery narrows and a blood clot will form inside the artery. Both conditions are dangerous, because the blood clot can travel to the hand and block blood circulation. Symptoms include the hand becoming numb, cold, pain or discoloration, pain or soreness of the fingers, and poor blood circulation to the arms, hands and fingers. Treatment to restore blood circulation is essential.
- Nonspecific-type thoracic outlet syndrome is also known as disputed thoracic outlet syndrome. Some physicians report it as a common disorder, while others do not believe the condition exists. Often, patients with nonspecific-type TOS suffer from a chronic pain in the thoracic outlet that worsens with physical activity; however, doctors are unable to determine the cause of the pain. Symptoms normally begin after a car accident, or other physically traumatic event.
DIAGNOSIS
Physicians diagnose TOS after a complete physical examination and may refer patients for evaluation by a neurologist. Tests to diagnose TOS may include:
- Chest x-ray
- CT scan or MRI of the spine or chest
- Blood tests
- Vascular studies
- Nerve conduction studies
- Arteriogram/venogram
TREATMENT
While thoracic outlet syndrome typically cannot be prevented, treatment options may include:
- Physical therapy is the most common form of initial treatment for TOS and strengthens muscles, promotes better posture and helps to increase range of motion of injured shoulders and neck. Physical therapy exercises may help relieve the pressure on nerves and blood vessels in the thoracic outlet.
- Over-the-counter medications may be prescribed by your doctor such as aspirin, ibuprofen, Tylenol, etc. to help with inflammation, pain and encourage muscle relaxation.
- Surgery is only required for approximately 10-20 percent of TOS patients. The primary goal of surgery for TOS treatment is to eliminate the compression on nerves and blood vessels. Surgery to remove part or all of a rib that may be the underlying cause of the TOS is called decompression. Surgical complications may include nerve injury, bleeding, fluid leakage, or collapsed lung. Typically all patients diagnosed with venous or arterial TOS need surgical treatment while only some patients with neurogenic TOS require surgery.
If left untreated, TOS can cause problems such as:
- Death of body tissue, caused by loss of blood flow
- Permanent nerve damage
- Blood clot
- Permanent arm swelling and pain
- Ulcer(s) on the finger(s) due to decreased blood flow
- Blood vessel obstruction