Thoracic Outlet Syndrome (TOS): Causes, Symptoms, and Treatment

What is Thoracic Outlet Syndrome?

Thoracic outlet syndrome occurs when there is pressure or compression of the brachial plexus (a network of nerves that control the muscles and sensation of the arm and hand) or the subclavian artery/vein. The condition is categorized into three main types based on which structures are being compressed:

1. Neurogenic TOS: Compression of the brachial plexus nerves, which is the most common form of TOS (over 90% of cases).

2. Venous TOS: Compression of the subclavian vein, leading to swelling and possible blood clots in the arm.

3. Arterial TOS: Compression of the subclavian artery, leading to reduced blood flow to the arm and hand, and in rare cases, can result in aneurysms or blood clots.

Causes of Thoracic Outlet Syndrome

Several factors can lead to thoracic outlet syndrome, including anatomical anomalies, repetitive trauma, and poor posture. Common causes include:

1. Anatomical Abnormalities:

   • Extra rib (cervical rib): Some people are born with an extra rib above the first rib, which can compress the brachial plexus or blood vessels.

   • Abnormalities of the collarbone or first rib: Any abnormal growth or shape of the collarbone or first rib can decrease the space in the thoracic outlet, leading to compression.

2. Postural Issues:

   • Poor posture: Slouching or forward head posture can cause the muscles and ligaments around the thoracic outlet to become tight and compress the nerves or blood vessels.

3. Repetitive Movements:

   • Jobs or activities that involve repetitive overhead motions, heavy lifting, or arm movements can lead to TOS, as the muscles and tendons in the area can become irritated, inflamed, and lead to compression of the neurovascular structures.

4. Trauma or Injury:

   • Car accidents or sports injuries can lead to damage or scarring of tissues around the thoracic outlet, leading to restricted space and compression.

5. Obesity:

   • Excess weight or carrying heavy loads can lead to additional strain on the shoulder and neck muscles, contributing to TOS.

Symptoms of Thoracic Outlet Syndrome

The symptoms of thoracic outlet syndrome can vary depending on the type of compression (neurological, venous, or arterial) and the severity of the condition. Common symptoms include:

Neurogenic TOS (Nerve Compression):

• Pain: A dull ache or sharp pain in the neck, shoulder, and upper arm, which may worsen with overhead activities or lifting.

• Numbness and tingling: A sensation of "pins and needles" in the fingers, hand, or arm.

• Weakness: Difficulty with hand strength or grip, and a general sense of weakness in the arm and hand.

• Muscle atrophy: In severe cases, the muscles in the hand or forearm may shrink or weaken over time.

Venous TOS (Vein Compression):

• Swelling: Swelling in the arm or hand, particularly after activity or prolonged use of the arm.

• Discoloration: A bluish or reddish tint to the hand or arm due to reduced blood flow.

• Pain: A deep ache or heaviness in the affected arm or hand, which may worsen after physical activity.

Arterial TOS (Artery Compression):

• Coldness: The arm or hand may feel cold to the touch, particularly when holding it in certain positions.

• Paleness: The affected arm or hand may appear pale due to reduced blood flow.

• Weak pulse: A weak or absent pulse in the arm due to restricted blood flow.

• Clots: In rare cases, blood clots may form in the affected arm or hand, leading to more severe complications like deep vein thrombosis (DVT).

Diagnosing Thoracic Outlet Syndrome

Diagnosing thoracic outlet syndrome involves a comprehensive clinical evaluation, which may include:

1. Physical Examination:

   • A healthcare provider will conduct a thorough examination, assessing posture, muscle strength, and the range of motion of the neck, shoulders, and arms. Special tests, such as Adson's test, Roos test, or Wright's test, may be used to check for compression of the nerves or blood vessels in the thoracic outlet.

2. Imaging Tests:

   • X-rays can reveal structural abnormalities, such as an extra rib or changes to the collarbone and first rib.

   • MRI or CT scans can provide more detailed images of soft tissues, including nerves, muscles, and blood vessels, to assess for compression.

   • Ultrasound can be used to evaluate blood flow and detect venous or arterial blockages.

3. Nerve Conduction Studies:

   • These tests measure the electrical activity in the nerves and can help assess whether the brachial plexus is being compressed.

Treatment for Thoracic Outlet Syndrome

Treatment for thoracic outlet syndrome aims to relieve compression of the nerves or blood vessels and restore normal function to the arm and hand. Treatment options vary based on the type of TOS and its severity.

Non-Surgical Treatment

1. Physical Therapy:

   • Posture correction: A physiotherapist can guide posture training to reduce stress on the thoracic outlet and improve the alignment of the shoulders and neck.

   • Strengthening exercises: Targeting the muscles around the thoracic outlet, including the shoulder girdle and upper back muscles, can help alleviate pressure on the nerves and blood vessels.

   • Stretching exercises: Gentle stretches of the neck, shoulders, and upper back muscles can relieve tightness and improve mobility.

   • Neurodynamics: Techniques that aim to mobilize the nerves and reduce their compression.

2. Pain Management:

   • Non-steroidal anti-inflammatory drugs (NSAIDs): Medications like ibuprofen can help reduce pain and inflammation associated with TOS.

   • Corticosteroid injections: In some cases, injections of corticosteroids can be used to reduce inflammation and alleviate pain.

3. Ergonomic Adjustments:

   • Modifying workstations or activity environments to improve posture and avoid repetitive strain can help prevent further episodes of TOS.

   • Use of proper lifting techniques and avoiding prolonged overhead positions can reduce symptoms.

4. Heat and Cold Therapy:

   • Applying heat or cold packs to the affected area can help reduce inflammation and relieve muscle tightness.

Surgical Treatment

If conservative treatments are ineffective, surgery may be recommended to address structural causes of thoracic outlet syndrome, such as an extra rib or severely compressed nerves. Surgical options may include:

1. First Rib Resection:

   • Removal of the first rib or part of the rib may be performed to create more space in the thoracic outlet and relieve pressure on the nerves or blood vessels.

2. Scalenectomy:

   • The removal of a portion of the scalene muscles in the neck can help alleviate compression of the brachial plexus nerves.

3. Decompression of Blood Vessels:

   • If the compression involves blood vessels (artery or vein), surgical procedures to remove the compression or repair damaged vessels may be required.

Recovery and Prognosis

The prognosis for thoracic outlet syndrome depends on the underlying cause and the timeliness of treatment. Many people experience relief with physical therapy and conservative treatment, while others may require surgery.

1. Recovery Time:

   • Non-surgical treatments: Many individuals will experience significant improvement within a few weeks to months of starting physical therapy and pain management.

   • Surgical recovery: Recovery after surgery may take several months. Physical therapy post-surgery is typically needed to restore function and strength to the shoulder and arm.

2. Prevention:

   • Maintaining good posture, avoiding repetitive overhead motions, and strengthening the shoulder and upper back muscles can help prevent recurrence of TOS.

Prevention of Thoracic Outlet Syndrome

To reduce the risk of developing thoracic outlet syndrome:

1. Posture: Maintain proper posture, particularly when sitting for long periods or performing repetitive tasks. Avoid slouching or leaning forward.

2. Strengthening: Regular exercises to strengthen the muscles of the neck, shoulders, and upper back can reduce strain on the thoracic outlet.

3. Ergonomic Adjustments: Ensure your workstation is set up correctly, with the proper chair height, keyboard placement, and screen angle.

4. Avoid Overhead Activities: Limit activities that require repeated overhead motions or heavy lifting without proper training or support.

Expert Care at Palms Physiotherapy & Allied Health

At Palms Physiotherapy & Allied Health, we specialize in diagnosing and treating thoracic outlet syndrome. Our experienced physiotherapists will work with you to develop a tailored rehabilitation plan to address your specific symptoms, improve your posture, and reduce any compression of the nerves or blood vessels.