What is Thoracic Outlet Syndrome?
Thoracic Outlet Syndrome or TOS is a condition where the superior thoracic outlet is compressed resulting in compression in the middle scalene and anterior scalene of a neurovascular bundle (consists of the C8 and T1 nerves plus the brachial plexus and subclavian vein and artery).
The syndrome can compress the subclavian artery or the brachial plexus. The brachial plexus is the collection of sensory and motor nerves that innervate the hand, arm, and the shoulder girdle whereas the subclavian vein and artery supply blood to the area.
The Thoracic Outlet
Thoracic outlet syndrome can be static or positional. Static TOS is caused by conditions such as spasm or enlargement of muscles adjacent to the blood vessels or brachial plexus. Positional TOS is brought about by movement of the shoulder girdle or the clavicle.
Thoracic Outlet Syndrome
Thoracic Outlet Syndrome can be classified by:
Structure affected and symptomatology Thoracic outlet syndrome can be classified according to the structures involved which include:
a. Arterial Thoracic outlet Syndrome– involves the compression of the subclavian artery
b. Neurogenic Thoracic Outlet Syndrome– involves the compression of the brachial plexus. This is the most common type of TOS and accounts to almost 95% of the cases.
c. Venous Thoracic outlet Syndrome– involves the compression of the subclavain vein
Thoracic outlet syndrome can be caused by several factors including trauma and non-ergonomic postures.
Structure causing Constriction
Thoracic outlet Syndrome can also be classified according to the structure that causes compression which include:
- Cervical Rib syndrome – involves the compression of the neurovascular bundle as a result of congenital bone growth above the first rib.
- Scalenus anticus syndrome– this involves the compression of the neurovascular bundle as a result of muscle growth
- Costoclavicular syndrome – this involves the compression of the neurovascular bundle as a result of narrowing at the space between the first rib and clavicle
Thoracic Outlet Syndrome Symptoms
Symptoms of TOS usually involve the upper extremities. Symptoms include:
- Continuous pain in the arms and hands, side of the neck, axilla, pectoral in the clavicle, upper back, rhomboid and trapezius area
- Cold, clammy hand in comparison to the other hand
- Swollen, cyanotic arm after strenuous activity (could be a sign of venous compression or thrombosis)
- Heavy feeling on the arms
- Superficial vein distention observed in the arms and hands
- Weakness of the arms
- Tingling sensation or paresthesia in the forearm and palm, neck and shoulders
- Pain characterized as burning, sharp or aching
- Pain can be felt on all parts of the hand or in a particular part only such as the 5th finger
- Atrophy of the muscles in the hand
- Muscles cramps in the arm
- Poor fine motor skills
Compression of the neurovascular bundle can be caused by:
Prolonged static posture can be experienced by students, line workers, cashiers, and others which yield compression of the space between the first rib and the clavicle.
Weakness of the bones can lead to an increased kyphosis that result in TOS
Carrying of heavy loads on the shoulders or arms
This stresses the supporting structures in the clavicle or shoulders. Costoclavicular approximation (compression of the space between the first rib and the clavicle) due to poor posture or weight lifting may result.
Repetitive overhead movement of the arms
Compression can result from hyperextension of the shoulder joint as seen in painters, electricians, volleyball players, swimmers, baseball pitchers, tennis players. The trauma results from stretching of the muscles which results to tears. There is also resulting pectoralis minor tightness caused by repetitive shoulder elevation.
Congenital Cervical Rib
The growth of an extra rib above the first rib may cause compression of the brachial plexus passing on the area. Tightness of the anterior scalene muscles caused by nerve root irritation may also result. Other causes may include:
- Tumors on the upper chest that compresses the neurovascular bundle
- Large lymph nodes on the neck, thorax and axilla
- Sleep disorders
- Whiplash injury that results in injury to the neck and back
Diagnosis of TOS involves several tests and radiographic imaging. Specific diagnostic procedures include:
X-ray is usually done to determine the exact cause of TOS whether it is positional or static.
This test involves the placement of probes at the arms and fingertips and the patient is asked to perform various arm maneuvers. The presence of diminished arterial blood flow as seen in the graphs with sensation of pain and numbness indicates compression of the subclavian artery.
MRI of the brachial plexus is done to determine compression of the network.
Local anesthetics such as xylocaine are injected on the anterior scalene muscle, pectoralis minor or subclavius muscle. The presence of relief in one to two hours indicates the presence of compression in the area.
Thoracic Outlet Syndrome Tests
Orthopedic tests are also done to diagnose specific types of TOS. These tests include:
This test is done by rotating the head of the patient toward the affected arm while tilting it backward. The examiner extends the arm and palpates for the radial pulse. The sudden disappearance of the radial pulse while doing the maneuver is a positive indication for TOS.
This is performed by locating the pulse then drawing the shoulder downwards and backwards. The patient maintains an exaggerated lifting of the chest (attention stance). Positive result is when the pulse disappears.
Hands-Up test of East Test
The hands are brought up with the elbows behind the head. The patient then slowly opens and closes the hand for about 3 minutes. Presence of pain, weakness and paresthesia on the arms indicate a positive result.
Stick them up Hand Raise
The arms are bent on a right angle at the elbows overhead. A positive test involves paleness on the affected arm due to compromised circulation in the area.
Pressure is placed on the medial humeral head and clavicle. Numbness or radiation of pain in the affected arm is a positive result.
This test involves the flexion of the elbow at 90 degrees by the examiner while the shoulder is rotated laterally and extended horizontally. The patient turns the head away from the tested arm and the disappearance of pulse while the patient turns the head is an indication for TOS.
Thoracic Outlet Syndrome Treatment
Managements of TOS include conservative treatments and surgery. Thoracic Outlet Syndrome Physical Therapy Physical therapy is needed to allow the affected arm to move optimally. Physiotherapy relieves compression in the thorax, blood vessels and nerves. It also improves the condition of the ligaments, tendons, bones and muscles. Physical therapy is also used to maximize the result of surgery. Physiotherapy is employed by physical therapists. The specific treatment depends on the cause and type of TOS.
Thoracic Outlet Syndrome Stretches
Self-stretching routines help in alleviating pain and other symptoms. However, these do not directly cure the condition. The stretching techniques should be performed wherein the stretch should be felt with no pain. The position is held for 30 seconds and repeated up to five times with an interval of 10 seconds. Whenever symptoms persist, it is best to consult a physician.
Stretching the back and side of the neck
This is done while sitting in a chair. Do this by holding the head with the unaffected arm and grasping the side of the chair with the affected arm. Gently pull the head side ward away from the affected shoulder while using the affected arm to grasp the side of the chair.
Stretching the chest
Place hands clasped behind the head. Bring the elbows back while inhaling, as far as possible. After this, bring the elbows in front while inhaling, as far as possible.
Stretching the shoulder
Sit in a chair at a side of a table. Extend the arms over the table with palms down. Slowly slide the palms as far as possible while bending at the waist. This can also be done by sitting in a chair then grasp the side of the chair with the affected arm. Lean side ward as far as possible.
Stretching the first rib
Do this by placing a large cloth across the affected shoulder. Meet the two ends of the cloth at the opposite hip like placing a sash. Slowly pull the ends downward to stretch the first rib.
Aside from stretching, exercise is also done using the following:
Nerve gliding exercise
This exercise relieves tension on the nerves affected. This is done by abducting the affected arm while tilting the head to the unaffected side. This exercise must create a pulling sensation on the affected arm. It may create pain at the start, but disappears while the exercise is repeated.
Perform active breathing exercises while in an ergonomic position to maintain a good posture.
Thoracic Outlet Syndrome Surgery
Some TOS cannot be solely managed using conservative treatments discussed earlier. First rib resection or scalenectomy may be employed to permanently relieve the compression. These procedures remove the first rib, compressive fibrous tissues or the scalene muscles itself. Surgery relives compression and improves blood flow to the area. The presence of a cervical rib may also be removed using rib resection.
Cold and warm packs
Cold compresses aid in reducing swelling and inflammation while warm packs relieve muscle spasms. This can be done alternately for 15 to 30 minutes.
Cortisone can be injected into a muscle or joint to relieve inflammation.
Small amounts of Botox injections can be administered over a spastic or tight muscle to temporarily relax the muscles. Botox treatment usually takes effect for 3 to 4 months and can be quite expensive.
Thoracic outlet syndrome has a good prognosis. The outcome of the treatment depends on the type and cause. Most of the cases are responsive to physical therapy, stretches and other exercises. However, neurogenic TOS or vascular TOS may need surgical intervention to effectively release the compression.
When left untreated, Thoracic outlet syndrome may result to the following:
- Gangrene of the affected area
- Permanent swelling and pain on the arms
- Pulmonary embolism
- Ischemia of the fingers
- Ulcerations due to poor perfusion
- Permanent nerve damage
Thoracic outlet syndrome not caused by congenital cervical rib can be prevented by the following measures:
- Avoid heavy lifting. Use mechanical lifters instead.
- Ensure adequate rest periods in between activities that hyper abducts the arms and shoulders.
- Carry shoulder bags or suitcases at different side of the shoulder to prevent overuse of one side.
- Maintain good posture at all times.
- Engage in exercises involving the arms and shoulders.
- Maintain a neutral sleeping position.
- Include calcium in the diet to prevent osteoporosis.
Some TOS types cannot be prevented such as in cases of a cervical rib, large lymph nodes and tumor in the upper chest. In these cases, prompt consultation is needed to prevent complications.
Thoracic Outlet Syndrome Pictures