What is Thoracic Outlet Syndrome?
Thoracic outlet syndrome (TOS) is a general term used to describe a range of conditions that cause compression on the nerves and blood vessels passing through an area in the upper body called the thoracic outlet. This was first identified by Rogers in 1949 and later accurately described by Rob and Standeven in 1958. There are five different kinds of TOS, as suggested by Wilbourne, which include versions caused by vein problems, artery issues, trauma, nerve damage, and a type that is disputed or unclear.
The thoracic outlet, where this condition occurs, is formed by the first rib, the collarbone, and certain muscles in the neck. People with TOS can experience a variety of symptoms, ranging from minor discomforts to very severe issues that can limit normal activities. To identify this condition, doctors often use special imaging techniques to look at the muscles, nerves, and blood vessels in that area. If it’s suspected that the condition is caused by nerve damage, tests to check the nerves’ function can also be helpful.
Both non-surgical treatments and surgical procedures are available to manage TOS. If treated accurately, most patients recover well, with majority of them finding complete relief from their symptoms.
What Causes Thoracic Outlet Syndrome?
Thoracic Outlet Syndrome (TOS) happens when pressures in the area between your collarbone and your first rib (known as the thoracic outlet) get too high, pinching blood vessels or nerves. This added pressure could be due to a variety of physical abnormalities like an extra rib in the chest area or tumors. Muscular people or those who overuse their muscles might experience this even without any physical abnormalities.
Past injuries or the way one positions their neck could also lead to this condition—it’s considered one of the most common reasons people get TOS.
Other, secondary causes could bring about TOS too. For instance, if a patient has a weak trapezius muscle (a major muscle in the back), it might cause their shoulder to hang low. This, in turn, can narrow the thoracic outlet and result in TOS. Similarly, a broken collarbone could lower the shoulder and cause the same problem.
Risk Factors and Frequency for Thoracic Outlet Syndrome
Thoracic Outlet Syndrome (TOS) comes in different forms, but the most common one is the neurogenic thoracic outlet syndrome, which makes up for over 90% of all TOS cases. TOS generally affects females more, as well as those with weak muscles or poor posture, or both. Because the symptoms are so general, it’s hard to figure out exactly how many people have TOS. However, estimates suggest that for every 1,000 people, between 3 to 80 could have TOS.
Signs and Symptoms of Thoracic Outlet Syndrome
Thoracic outlet syndrome (TOS) is a condition that can cause a variety of symptoms, and these can vary based on what’s causing the issue in the first place. One of the most commonly reported symptoms across all causes is a vague sense of pain. For example, a blockage in a vein could result in swelling in the upper arm, visible swollen veins, and pain ranging from the hand to the forearm. This might even lead to deep vein thrombosis (DVT) in the upper extremity.
If TOS is caused by an arterial issue, the patient may notice color changes in the upper extremity and weakened pulses. Neurogenic thoracic outlet syndrome, the most common type, occurs due to pressure on the brachial plexus (a network of nerves coming from the spinal cord and going to the arm). Symptoms of this type can include a vague sense of pain similar to the other types, weakening of the hand muscles, and sensory deficits.
- Vague sense of pain
- Swelling in the upper arm, visible swollen veins
- Pain ranging from the hand to the forearm
- Color changes in the upper extremity
- Weakened pulses
- Weakening of the hand muscles
- Sensory deficits
Physical exams are crucial for diagnosing TOS and understanding its cause. Checking posture, symmetry, and range of motion of the arms are typical starting points. Doctors may perform several exams and tests, like Spurling’s test, Adson Maneuver, and a neurological exam focusing on the upper extremity. The roos stress test might also be performed to examine fatigue and symptom reproduction.
Testing for Thoracic Outlet Syndrome
To diagnose thoracic outlet syndrome, a condition that causes tingling and pain in the neck and shoulders, doctors start with a physical exam. After the physical examination, they can confirm the diagnosis with additional tests.
The first test is usually a simple chest or neck x-ray. These x-rays can provide important information about the person’s body structure, which could be contributing to the problem.
An ultrasound might be used, but it’s not always helpful for thoracic outlet syndrome because it can’t visualize the entire affected area. But, according to Longley and colleagues, a test involving ultrasound achieved a 92% success rate for correctly identifying venous thoracic outlet syndrome, which is a variant of the condition that involves veins, and a 95% success rate for identifying true instances of the condition.
Angiography is a technique that produces detailed images of the blood vessels. In theory, it could be ideal for diagnosing arterial thoracic outlet syndrome, a form of the condition that affects the arteries. The problem is that arterial thoracic outlet syndrome often comes and goes and is difficult to trigger on demand, making this approach controversial.
Another test that may be utilized is a venous Doppler, which checks the flow of blood through your veins and can detect compression within vessels in the thoracic outlet. The great benefit of this method is that it allows doctors to have the patient mimic movements and positions that typically intensify thoracic outlet pressure.
Finally, electrodiagnostic studies (EMS) are a traditional method for diagnosing neurogenic thoracic outlet syndrome, which affects the nerves. Although this type of thoracic outlet syndrome can likewise be transient, if the test is positive, it confirms the diagnosis. A positive result is considered when there is a reduction in nerve speed of less than 85 meters per second. If the overall speed is less than 60 meters per second, it’s usually considered a sign that surgery is needed.
Treatment Options for Thoracic Outlet Syndrome
Thoracic outlet syndrome, a condition that involves pain in the neck and shoulder, numbness and tingling of the fingers, is usually treated through either lifestyle changes and physical therapy, or surgery. Often, the preferred first response is to try lifestyle modifications and physical therapy, unless the patient’s symptoms are extremely severe and debilitating.
Lifestyle changes required can include maintaining a correct posture, sleeping without elevating the arms, and using supportive splints or padding in work settings that require repetitive motions. The goal is to help relieve pressure thus reducing symptoms.
Physical therapy is a common first treatment for this condition. The aim is to strengthen the muscles around the thoracic outlet (the space between your collarbone and your first rib), thereby easing the pressure on the affected area. This type of therapy has been found to help manage and alleviate symptoms in many patients.
In more extreme cases, where toracic outlet syndrome has caused notable structural damage or significant complications, rehabilitation comes in. Rehabilitation mimics physical therapy in its goal to strengthen the affected muscles but it also includes efforts to restore any lost normal functions.
Surgery is a more controversial treatment option. While it may be recommended for those experiencing severe problems or muscle loss in the hand, surgery should only be considered when there is credible and substantial evidence. Due to the symptoms of thoracic outlet syndrome being often general and vague, it can be difficult to get this evidence. Hence, recent studies suggest that surgery should be cautiously approached as it might lead to complications and work disabilities post operation. Therefore, many doctors typically don’t advise surgery unless absolutely necessary.
What else can Thoracic Outlet Syndrome be?
Thoracic outlet syndrome (TOS) can be quite complex to diagnose because the symptoms have similarities with many other pain conditions or injuries. One condition that’s often mistaken for TOS is Pectoralis minor syndrome (PMS). People with PMS usually feel pain in the front part of their chest wall, the large muscle of their upper back (trapezius muscle), and near their shoulder blades. However, they also experience arm and hand pain or abnormal sensations. The cause of PMS is due to the pectoralis minor muscle pressing on nerves, rather than an issue in the thoracic outlet where TOS originates.
Other conditions that can be mixed up with TOS include:
- Brachial plexus injuries – an issue with the network of nerves that sends signals from your spine to your shoulder, arm and hand
- Cervical spine injuries – injuries to the neck portion of the spine
- Cervical radiculopathy – an irritation or swelling of a nerve in the neck that can cause symptoms in the arm or hand
- Shoulder impingement syndrome – irritation or damage to the rotator cuff from rubbing against a part of the shoulder blade
- Overuse injuries of the elbow or forearm
- Acromioclavicular joint injury – a problem with the joint at the top of the shoulder
What to expect with Thoracic Outlet Syndrome
In general, people with thoracic outlet syndrome – a condition in which nerves or blood vessels in the space between your collarbone and your first rib are compressed – have excellent chances of recovery. Around 90% of patients find relief from their symptoms through non-surgical treatments. Most of these patients do not experience a recurrence of the condition, particularly if their injury was not caused by repetitive movements. For those whose condition was triggered by repetitive actions, changes in lifestyle habits can play a crucial role in preventing another episode.
It’s recommended that activities where the arms remain raised for long periods of time should be avoided if possible for the best outcome.
Possible Complications When Diagnosed with Thoracic Outlet Syndrome
TOS, or Thoracic Outlet Syndrome, tends to have a mild nature without many complications because it develops slowly and most treatments are non-threatening. However, if the blood supply gets cut off, it can lead to tissue damage. In severe cases, venous gangrene, which is the death of body tissue due to lack of blood flow, or phlegmasia cerulea dolens, a rare condition where blood clots block veins in the legs, can occur.
Most of the complications come from surgical treatment, which is why most doctors suggest non-surgical therapies. Potential complications from surgery include accidental nerve damage, lung collapse from the removal of a part of the top rib, and bleeding which is less common but still a risk.
Side Effects:
- Tissue damage due to lack of blood supply
- Venous gangrene
- Phlegmasia cerulea dolens (rare, severe condition where veins in the legs are blocked)
- Accidental nerve damage from surgery
- Lung collapse from surgical removal of a part of top rib
- Bleeding due to surgical complications (although less common)
Preventing Thoracic Outlet Syndrome
Thoracic outlet syndrome (TOS) is a group of problems that occur when either blood vessels or nerves in a certain area are squeezed too tight. This pressure can cause a variety of symptoms such as numbness, tingling, and weakness in the affected area. Though medical imaging can be used to help figure out what might be causing the issue, it isn’t always required to diagnose TOS.
The first line of treatment for TOS usually involves non-surgical methods like physical therapy, and most patients respond well to this approach. In more severe cases, other treatment options might be necessary, including botox injections and surgery.
Once a patient’s TOS is under control and the symptoms have disappeared, they may need to continue with physical therapy to help prevent the problem from coming back. Alongside these preventive treatments, it’s also recommended that patients avoid repetitive tasks and refrain from lifting heavy objects over their heads as much as possible. This helps to reduce the chance of the condition reoccurring.
