Overview

Thoracic outlet syndrome is a group of disorders that occur when blood vessels or nerves in the space between your collarbone and your first rib (thoracic outlet) are compressed. This can cause pain in your shoulders and neck and numbness in your fingers.

Common causes of thoracic outlet syndrome include physical trauma from a car accident, repetitive injuries from job- or sports-related activities, certain anatomical defects (such as having an extra rib), and pregnancy. Sometimes doctors can't determine the cause of thoracic outlet syndrome.

Treatment for thoracic outlet syndrome usually involves physical therapy and pain relief measures. Most people improve with these approaches. In some cases, however, your doctor may recommend surgery.

Thoracic outlet syndrome care at Mayo Clinic

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Symptoms

There are a number of types of thoracic outlet syndrome, including:

• Neurogenic (neurological) thoracic outlet syndrome. This form of thoracic outlet syndrome is characterized by compression of the brachial plexus. The brachial plexus is a network of nerves that come from your spinal cord and control muscle movements and sensation in your shoulder, arm and hand. In the majority of thoracic outlet syndrome cases, the symptoms are neurogenic.
• Vascular thoracic outlet syndrome. This type of thoracic outlet syndrome occurs when one or more of the veins (venous thoracic outlet syndrome) or arteries (arterial thoracic outlet syndrome) under the collarbone (clavicle) are compressed.
• Nonspecific-type thoracic outlet syndrome. This type is also called disputed thoracic outlet syndrome. Some doctors don't believe it exists, while others say it's a common disorder. People with nonspecific-type thoracic outlet syndrome have chronic pain in the area of the thoracic outlet that worsens with activity, but a specific cause of the pain can't be determined.

Thoracic outlet syndrome symptoms can vary, depending on which structures are compressed. When nerves are compressed, signs and symptoms of neurological thoracic outlet syndrome include:

• Muscle wasting in the fleshy base of your thumb (Gilliatt-Sumner hand)
• Numbness or tingling in your arm or fingers
• Pain or aches in your neck, shoulder or hand
• Weakening grip

Signs and symptoms of vascular thoracic outlet syndrome can include:

• Discoloration of your hand (bluish color)
• Arm pain and swelling, possibly due to blood clots
• Blood clot in veins or arteries in the upper area of your body
• Lack of color (pallor) in one or more of your fingers or your entire hand
• Weak or no pulse in the affected arm
• Cold fingers, hands or arms
• Arm fatigue with activity
• Numbness or tingling in your fingers
• Weakness of arm or neck
• Throbbing lump near your collarbone

When to see a doctor

See your doctor if you consistently experience any of the signs and symptoms of thoracic outlet syndrome.

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Causes

In general, the cause of thoracic outlet syndrome is compression of the nerves or blood vessels in the thoracic outlet, just under your collarbone (clavicle). The cause of the compression varies and can include:

• Anatomical defects. Inherited defects that are present at birth (congenital) may include an extra rib located above the first rib (cervical rib) or an abnormally tight fibrous band connecting your spine to your rib.
• Poor posture. Drooping your shoulders or holding your head in a forward position can cause compression in the thoracic outlet area.
• Trauma. A traumatic event, such as a car accident, can cause internal changes that then compress the nerves in the thoracic outlet. The onset of symptoms related to a traumatic accident often is delayed.
• Repetitive activity. Doing the same thing repeatedly can, over time, wear on your body's tissue. You may notice symptoms of thoracic outlet syndrome if your job requires you to repeat a movement continuously, such as typing on a computer, working on an assembly line or lifting things above your head, as you would if you were stocking shelves. Athletes, such as baseball pitchers and swimmers, also can develop thoracic outlet syndrome from years of repetitive movements.
• Pressure on your joints. Obesity can put an undue amount of stress on your joints, as can carrying around an oversized bag or backpack.
• Pregnancy. Because joints loosen during pregnancy, signs of thoracic outlet syndrome may first appear while you're pregnant.

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Diagnosis

Diagnosing thoracic outlet syndrome can be difficult because the symptoms and their severity can vary greatly among people with the disorder. To diagnose thoracic outlet syndrome, your doctor may review your symptoms and medical history and conduct a physical examination.

• Physical examination. Your doctor will perform a physical examination to look for external signs of thoracic outlet syndrome, such as a depression in your shoulder, swelling or pale discoloration in your arm, abnormal pulses, or limited range of motion.
• Medical history. Your doctor will likely ask about your medical history and symptoms, as well as your occupation and physical activities.

Provocation tests

Provocation tests are designed to try to reproduce your symptoms. The tests may help your doctor determine the cause of your condition and help rule out other causes that may have similar symptoms.

In these tests, your doctor may ask you to move your arms, neck or shoulders in various positions. Your doctor will check your symptoms and examine you in different positions.

Imaging and nerve study tests

To confirm the diagnosis of thoracic outlet syndrome, your doctor may order one or more of the following tests:

• X-ray. Your doctor may order an X-ray of the affected area, which may reveal an extra rib (cervical rib). X-rays also may rule out other conditions that may be causing your symptoms.
• Ultrasound. An ultrasound uses sound waves to create images of your body. Doctors may use this test to see if you have vascular thoracic outlet syndrome or other vascular problems.
• Computerized tomography (CT) scan. A CT scan uses X-rays to obtain cross-sectional images of your body. A dye may be injected into a vein to view the blood vessels in greater detail (CT angiography). A CT scan may identify the location and cause of blood vessel (vascular) compression.
• Magnetic resonance imaging (MRI). An MRI uses powerful radio waves and magnets to create a detailed view of your body. Your doctor may use an MRI to determine the location and cause of blood vessel (vascular) compression. An MRI may reveal congenital anomalies, such as a fibrous band connecting your spine to your rib or a cervical rib, which may be the cause of your symptoms.
• Angiography. In some cases, you may be given an intravenous dye before a CT or MRI scan. The dye helps to make blood vessels more visible on the images.

• Arteriography and venography. In these tests, your doctor inserts a thin, flexible tube (catheter) through a small incision, usually in your groin. The catheter is moved through your major arteries in arteriography, or through your veins in venography, to the affected blood vessels. Then your doctor injects a dye through the catheter to show X-ray images of your arteries or veins.

  Doctors can check to see if you have a compressed vein or artery. If a vein or artery has a clot, doctors can deliver medications through the catheter to dissolve the clot.

• Electromyography (EMG). During an EMG, your doctor inserts a needle electrode through your skin into various muscles. The test evaluates the electrical activity of your muscles when they contract and when they're at rest.
• Nerve conduction study. These tests use a low amount of electrical current to test and measure your nerves' ability to send impulses to muscles in different areas of your body. This test can determine if you have nerve damage.

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Complications

If your symptoms haven't been treated early, you may experience progressive nerve damage, and you may need surgery. Doctors recommend surgery to treat thoracic outlet syndrome only when other treatments haven't been effective. Surgery has higher risks than do other treatments and may not always treat your symptoms.

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Prevention

Thoracic outlet syndrome that goes untreated for years can cause permanent neurological damage, so it's important to have your symptoms evaluated and treated early, or take steps to prevent the disorder.

If you're susceptible to thoracic outlet compression, avoid repetitive movements and lifting heavy objects. If you're overweight, you can prevent or relieve symptoms associated with thoracic outlet syndrome by losing weight.

Even if you don't have symptoms of thoracic outlet syndrome, avoid carrying heavy bags over your shoulder, because this can increase pressure on the thoracic outlet. Stretch daily, and perform exercises that keep your shoulder muscles strong.

Lifestyle and home remedies

If you're diagnosed with thoracic outlet syndrome, your doctor or physical therapist will instruct you to do exercises at home to strengthen and support the muscles surrounding your thoracic outlet.

In general, to avoid unnecessary stress on your shoulders and muscles surrounding the thoracic outlet:

• Maintain good posture
• Take frequent breaks at work to move and stretch
• Maintain a healthy weight
• Avoid carrying heavy bags over your shoulder
• Avoid activities that worsen symptoms, or find ways to adapt activities so that they don't cause symptoms
• Create a work area that allows you to keep good posture and doesn't make symptoms worse

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Coping and support

Symptoms associated with thoracic outlet syndrome can be caused by a number of other conditions, which makes it difficult for doctors to diagnose the condition. Many people experience thoracic outlet syndrome symptoms for years before they are diagnosed with the condition, which can cause stress and frustration. Be sure to discuss your concerns with your doctor if your symptoms persist and a diagnosis hasn't been made.

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Risk factors

There are several risk factors that seem to increase the risk of thoracic outlet syndrome, including:

• Sex. Females are far more likely to be diagnosed with thoracic outlet syndrome than are males.
• Age. Thoracic outlet syndrome is more common in young adults, between 20 and 40 years old.

Source: http://www.mayoclinic.com