Thoracic outlet syndrome

Overview

Thoracic outlet syndrome (TOS) is a group of conditions caused by pressure on blood vessels or nerves in the area between the neck and shoulder. This space is known as the thoracic outlet. Pressure on the blood vessels and nerves can cause shoulder and neck pain. Also, it can cause the fingers to feel numb.

There are three types of thoracic outlet syndrome:

• Neurogenic thoracic outlet syndrome. About 95% of people who have TOS have this type. In neurogenic TOS, nerves around the shoulder are pinched. These nerves form the brachial plexus. They come from the spinal cord and control movements and feeling in the arms, shoulders and hands. When the nerves are pinched, pain or numbness may happen in these areas. When the condition is severe, nerves can be damaged and muscle strength or tissue can be lost.
• Venous thoracic outlet syndrome. About 4% of people with TOS have this type. In venous TOS, a vein under the collarbone called the subclavian vein is squeezed and damaged. This can cause swelling, pain and changes in skin color in the shoulder, arm or hand. When the condition is severe, blood clots may form.
• Arterial thoracic outlet syndrome. This least common type happens in about 1% of people with TOS. In this type, an artery under the collarbone called the subclavian artery is pressed. This can cause pain, coldness, and changes to the pulse or skin color in the arm or hand. When the condition is severe, the pressure can damage the artery. This can lead to a bulge in the vessel, also known as an aneurysm. An aneurysm is a life-threatening condition that can cause blood clots to form more easily.

Common causes of thoracic outlet syndrome include differences in the body, such as having an extra rib or one that is shaped differently. Trauma, repeated movements, or strain in the area between the neck and shoulders also can cause TOS. Sometimes the cause of thoracic outlet syndrome is not known.

TOS isn't common, but that may be because it's hard to diagnose. When it is diagnosed, people ages 20 to 50 tend to have the highest risk, especially women. One exception is venous TOS, which tends to affect younger men.

Treatment often involves physical therapy and pain relief. Most people get better with these treatments. For some, surgery may be needed.

Causes

Thoracic outlet syndrome often is caused by pressure on the nerves or blood vessels in the thoracic outlet. This is the area between the neck and shoulder. The cause of the pressure varies and can include:

• Differences in the body. Some people are born with an extra rib in the neck, above the first rib. The extra rib, known as a cervical rib, can press on nerves or blood vessels. Also, there may be a tight, thick band of tissue connecting the spine to the rib that causes pressure.
• Posture. How you hold your body can affect how much pressure is on the thoracic outlet. Drooping your shoulders or holding your head too far forward can put pressure on this area. Also, changes in posture that happen during pregnancy or when carrying a heavy bag over the shoulder can increase pressure on the nerves and vessels in the thoracic outlet.
• Repeating movements. Repeating the same arm movements for a job, sport or other daily activity can cause strain. Over time, this strain can damage the nerves and blood vessels of the thoracic outlet.
• Trauma. A traumatic event, such as a car accident, can cause changes inside the body that compress the thoracic outlet. As the body responds, injured tissues may swell or thicken. This process can put pressure on the nerves and vessels in this area and cause TOS.

Complications

Complications are health issues that can develop as a result of thoracic outlet syndrome. The type of thoracic outlet syndrome you have can affect what complications develop:

• Blood clots or aneurysms. These are a complication of arterial or venous TOS. When blood vessels are pinched, the arm may become swollen and painful and show a change in skin color. If this happens, seek medical care right away. You may need urgent treatment.
• Chronic pain or disability. This is a complication of neurogenic TOS. When the nerves are pinched over time, long-term damage can happen. Neurogenic TOS can be confused with other joint or muscle injuries. If symptoms don't get better, see your healthcare professional for testing.

Diagnosis

Diagnosing thoracic outlet syndrome can be hard. Symptoms can vary greatly among people. Members of your healthcare team will likely ask you questions and give you a physical exam. Also, you may need imaging and other types of tests.

Imaging and nerve study tests

To confirm the diagnosis of thoracic outlet syndrome, you may need one or more of the following tests:

• Ultrasound. An ultrasound uses sound waves to create images of your body. It's often the first imaging test used to help diagnose thoracic outlet syndrome. This test may be used to see if you have venous or arterial thoracic outlet syndrome or other vascular conditions.
• X-ray. An X-ray can reveal an extra rib, known as a cervical rib. X-rays also can help to rule out other conditions that could be causing your symptoms.
• Computerized tomography (CT) scan. A CT scan uses X-rays to get cross-sectional images of your body. A dye may be injected into a vein to view the blood vessels in greater detail, known as CT angiography. A CT scan may identify the location and cause of blood vessel compression.
• Magnetic resonance imaging (MRI). An MRI uses radio waves and magnetic fields to create a detailed view of your body. An MRI may be helpful to determine the location and cause of blood vessel compression. Sometimes dye is injected to better see the blood vessels. An MRI may reveal differences in anatomy, such as a fibrous band connecting your spine to your rib or a cervical rib. These differences in anatomy may be the cause of your symptoms. A healthcare professional may place your head, shoulders and neck in different positions. This may allow for a better view of the blood vessels in your arm.

• Arteriography and venography. In these tests, a thin, flexible tube called a catheter is inserted through a small cut, often in your groin. During arteriography, the catheter moves through your major arteries. During venography, the catheter moves through your veins. The catheter is threaded to the affected blood vessels. Then a dye is injected to show X-ray images of your arteries or veins.

  Healthcare professionals 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, a needle electrode is inserted through your skin into various muscles. The test checks the electrical activity of your muscles when they contract and when they're at rest. This test can determine if you have nerve damage.

Lifestyle and home remedies

If you're diagnosed with thoracic outlet syndrome, a physical therapist may tell you to do exercises at home. The exercises can strengthen and support the muscles around your thoracic outlet.

To support your shoulders and the muscles around the thoracic outlet:

• Keep good posture.
• Take frequent breaks at work to move and stretch.
• Keep a healthy weight.
• Create a work area that allows you to keep good posture and doesn't make symptoms worse.
• Gently massage your shoulders and thoracic outlet.
• Apply a heating pad to the area.
• Practice relaxation exercises such as deep breathing, meditation and stretching.

Preparing for an appointment

You're likely to start by seeing a member of your care team. Or you may be referred to a doctor trained in blood vessel conditions or blood vessel surgery, known as a vascular surgeon.

Here's some information to help you prepare for your appointment.

What you can do

• Be aware of anything you need to do ahead of time. When you make the appointment, ask whether there's anything you need to do before you come in.
• Write down any symptoms you're having. Include any that don't seem related to the reason you scheduled the appointment. Be as specific and detailed as possible in describing your symptoms. Include what part of your body is affected and how the discomfort makes you feel.
• Write down key personal information. Include any physical traumas you've experienced, even if the injuries happened years ago. Traumas may include a car accident or work-related injury. Note any physical activities or movements you tend to repeat now or repeated in the past. These may include movements done for work, sports, hobbies or other recreational activities.
• List key medical information. Include other conditions for which you're being treated. Also include the names of all prescription and nonprescription medicines or supplements that you're taking.
• Take a family member or friend along. Someone who comes with you may remember something that you missed or forgot.
• Write down questions. Ask members of your care team to answer them.

Preparing a list of questions helps you make the most of your time. For thoracic outlet syndrome, some basic questions to ask include:

• What's the most likely cause of my symptoms?
• What kinds of tests do I need?
• What treatments are available, and which treatment do you recommend for me?
• How likely is it that nonsurgical treatments will improve my symptoms?
• If nonsurgical treatments aren't effective, is surgery an option?
• Is there anything I can do to prevent symptoms from coming back?
• Will I need to change my job?
• Do I need to limit or give up activities that may be causing my symptoms?
• If you're recommending weight loss, how much weight do I need to lose to help my symptoms get better?
• I have other health conditions. How can I best manage them with this condition?
• Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?

Don't hesitate to ask any other questions you have.

What to expect from your doctor

Your healthcare professional will likely ask several questions, such as:

• When did you first notice your symptoms?
• How would you describe your symptoms?
• Have your symptoms changed over time?
• Where does your pain seem to start and where does it go from there?
• Does the pain or numbness worsen when you lift your arms overhead?
• Does anything else seem to worsen your symptoms or make them better?
• What activities do you do at your job?
• Do you or did you play sports?
• What are your hobbies or the recreational activities you do most often?
• Have you been diagnosed or treated for any other medical conditions? When?
• Have you noticed a lack of color or a change in color in one or more of your fingers or your entire hand? Have you noticed other changes to the area?

What you can do in the meantime

While you're waiting for your appointment, try taking a nonsteroidal anti-inflammatory drug (NSAID), such as ibuprofen (Advil, Motrin IB, others). Your discomfort also may lessen if you keep good posture and avoid lifting heavy objects and repeating the movements that cause strain.