What is Thoracic Outlet Syndrome?
Thoracic outlet syndrome (TOS) is not fully understood except we know it can be very painful and in some severe cases disabling. The condition affects blood vessels (arteries and veins), nerves, or both that travels from the spine, behind the collarbone and through the space above the first rib (costoclavicular space). Within this space, blood vessels and/or nerves are compressed causing pain, numbness, tingling, and possibly decreased blood flow to the arms and hands.
Most TOS cases are neurogenic, meaning damage to the nerve; however, there are cases that exist where the arteries or veins are affected too. TOS has four categories based on the structures involved and the symptoms. The four categories are:
- Arterial TOS
- Venous TOS
- True Neurogenic
- Disputed Neurogenic
Compression within the costoclavicular area is the most common location for compression; however, there are two other possible compression sites. The anterior and middle scalene muscle that runs along the front of the neck just off to the side and attaches to the first rib. The other, and less common, site are the in the front of the shoulder below the minor pectoralis tendon which attaches to the front of the shoulder area.
Neurogenic TOS is an injury to the brachial plexus nerve bundle. On each side of our body, this bundle of nerves exit the spinal column from the neck travels through the front chest and shoulder area, and down the arm to the hands. The entire bundle may be affected or just a particular nerve within the bundle; this can be determined by the symptoms one may be experiencing.
Our neck is called the cervical spine, and the chest and ribcage area is called the thoracic spine. In the cervical spine, we have seven vertebrae (bones within the spine) labeled C1-C7. Our thoracic spine has 12 vertebrae labeled T1-T12.
C1 is at the base of the skull, C7 is just at the base of the shoulder, and T1 is just below the base of the shoulder. Each level of the spine has a nerve that passes through and exits at the respective level. Levels C1-T1 after leaving the spine “bundle” together to form the brachial plexus. Neurogenic TOS may affect any or all the C1-T1 nerves.
What causes thoracic outlet syndrome?
Several factors are believed to cause thoracic outlet syndrome. There are some of us born with an extra rib, called the cervical rib. In congenital conditions such as this, it does not guarantee you will experience TOS, but it certainly puts you at higher risk. A few more common risk factors and causes of TOS are:
- Bulk muscles in the shoulder and neck from weight lifting
- Poor posture (rounded shoulders and forward head posture)
- Repetitive stress to shoulder with overhead sports (e.g. baseball, volleyball, swimming, etc.)
- Repetitive injuries from carrying weighted loads on the shoulder
- Trauma (e.g. current or previous fracture of the collarbone)
- Tumors in the upper lung or armpit area
- Weight gain
- Whiplash injury
There are some occupational hazards that increase the risk of TOS. For those occupations that have heavy use of the upper arms, this causes added stress to the tissue and structures within the thoracic area. A few jobs at higher risk may be (not all inclusive):
- Assembly line worker or inspector
- Construction (especially with use of jackhammers due to the vibration)
- Dental hygienists
- Drywall hanger or plasterer
- Shelf stocker
Symptoms of Thoracic Outlet Syndrome
More research needs to be done on TOS, but a common side effect is a depression. Researchers are not sure if the psychological changes come from the cause or effects of the injury. Symptoms can be severe and lead to dysfunction or disability of the affected upper extremity which can be challenging and frustrating for those who suffer from this condition.
There are specific symptoms for each of the four categories of TOS. They are:
- Arterial TOS
- Cold intolerance
- Numbness or tingling
- Pain in the hand
- Venous TOS
- Discoloration of the hand (bluish)
- Heavy arm sensation
- Numbness and tingling
- Pain and swelling in the arm
- True Neurogenic
- Cold intolerance
- Dropping items often
- Hand coldness
- Numbness, tingling, and pain in the neck, arm, and hand
- Disputed Neurogenic-all the symptoms of true neurogenic TOS, plus:
- Symptoms are the worst at night
- Tests come back normal or negative (thus disputed, or unexplained)
No matter the category of TOS, typically symptoms get worse with overhead activities, you may experience disturbed sleep, and/or your shoulder range of motion may be affected.
How is thoracic outlet syndrome diagnosed?
Thoracic outlet syndrome is complicated to diagnose due to the various symptoms that mimic other possible medical conditions like ulnar nerve entrapment or cervical radiculopathy. Your physician will complete a full medical history and physical exam of the neck, shoulders, arms, and hands. There are several common assessments your physician will perform to rule in, or out, the diagnosis of TOS. These assessments are:
- Adson test-the chin is lifted-up (neck extension), and the head is rotated towards the affected side; an abnormal result is while inhaling and holding the breath, the radial pulse changes, or it disappears altogether
- Costoclavicular test-downward pressure is applied to the affected shoulder; abnormal response is worsening of symptoms
- Roos test-the affected arm is abducted and externally (palm forward, arm lifted off to the side away from the body) for three mins while client opened and closed his or her fist slowly. An abnormal response is the inability to tolerate the test for three mins
- Wright test-affected arm is abducted and externally rotated; an abnormal response is loss of a radial pulse
These tests alone will not confirm a TOS diagnosis. If your physician suspects TOS, he or she will also likely perform an X-Ray, MRI (magnetic resonance imaging), EMG (electromyography), Doppler ultrasound, or even an angiogram. Each would be performed to rule out other possible medical conditions.
An X-Ray will provide a view of the spacing between the clavicle and 1st rib. An MRI will provide a view of the bone structure as well as the soft tissue in the area. Both the X-Ray or MRI will help your doctor determine where the possible compression is within the neck and shoulder area.
An EMG is a nerve conductivity test to rule in, or out, neurogenic TOS. The goal is to determine not only where the nerve may be compressed, but also how much damage is done to the nerve. The EMG sends signals to the nerve to see how well it is communicating throughout the arm and hand.
Although not widely used, a Doppler ultrasound is a specific test used to diagnose arterial or venous TOS. Research has mixed results of the reliability of a Doppler test; however, in some cases, it may be appropriate for proper diagnosis.
An angiogram may also be used to confirm arterial or venous TOS. A dye is used within the blood vessel to assess proper, or poor, blood flow.
Treatment of Thoracic Outlet Syndrome
Conservative treatment is typically prescribed especially for neurogenic TOS cases. TOS has responded well to physical or occupational therapy (PT or OT) Your PT or OT will complete a full evaluation to assess your condition thoroughly. He or she will establish specific goals with you to reduce symptoms and return you to functional activities.
Your PT or OT will likely do the following interventions to help open up the area of compression to alleviate the symptoms and improve function:
- Manual therapy-complete soft tissue mobilization (trigger point release and deep tissue massage), manipulate, and mobilize the area to improve mobility and to alleviate the pressure
- Muscle strengthening-strengthen proper postural muscles as well as any muscles affected with the injury to regain functional strength
- Posture training-work on proper posture (minimize forward head and rounded shoulders) techniques to reduce the area of compression
- Activity modification-education around activities that increase symptoms, he or she will teach you how to manage symptoms and when possible modify the activity to reduce symptoms
In addition to PT or OT, your physician may incorporate medications to help with pain and reducing inflammation. If conservative treatment is unsuccessful, in rare cases surgical intervention may be indicated.
Surgical intervention typically means the surgeon will remove the cervical rib (if in existence), the 1st rib, which opens up the costoclavicular space to remove the compressive structures. Depending on how the damage was done to the nerves and blood vessels, healing can be slow.
Post-operative PT or OT is typically prescribed by your surgeon. Your therapist will help manage symptoms from surgery as well as follow specific protocols with nerve glides, the range of motion, strengthening, etc. The goal is to return you to functional activities safely.
Early intervention to thoracic outlet syndrome is important. The sooner you address your symptoms, the more likely conservative care will work for you. As a consumer of health care, you have a choice in finding the right provider for you. Do your homework and search for a health care provider, like a physical therapist, with excellent outcomes, great customer reviews, and can provide you the care you need for a reasonable cost.
Most states have direct access to a physical therapist, meaning you can go directly to a physical therapist without a physician order. To determine if your state has direct access, please visit the American Physical Therapy Association’s website Physical Therapy Direct Access By State.
OTs typically work directly with your physician and surgeon on TOS protocols. He or she will collaborate with you and your physician and proper treatments and interventions. Direct access to OTs varies state to state and from insurer to insurer. It is best advised if you check with your insurance about OT coverage and requiements.
To get started with conservative care today, you can find a highly qualified PT or OT in your area. There are many qualified PTs and OTs, so to find one near you, please click on the following link (FOTO PT database link). This link will help you find a PT or OT that has top national rankings for treating conditions such as TOS.