What is thoracic outlet syndrome (TOS)?
Thoracic Outlet Syndrome (TOS) refers to a group of conditions characterized by compression of nerves, arteries, or veins in the thoracic outlet area, located between the base of the neck and the armpit. One common test used to diagnose TOS is the military brace test, also known as the military position test. This diagnostic maneuver involves positioning the shoulders and arms as if at attention, which can exacerbate symptoms in affected individuals.
A prevalent subtype of TOS is Costoclavicular Syndrome, where compression occurs between the clavicle and the first rib. Symptoms of TOS can vary but often include pain, numbness, tingling, or weakness in the upper extremity. During the costoclavicular test, clinicians may also assess for a weakened or absent radial pulse, indicating vascular involvement.
A cervical rib, an extra one above the first rib, can predispose individuals to TOS. Additionally, performing the military brace test or deep breath maneuvers may elicit positive findings, further supporting the diagnosis. Treatment options for TOS range from conservative measures like physical therapy to surgical intervention, depending on the severity and underlying cause. Early detection and intervention are crucial for managing symptoms and improving the quality of life for individuals with TOS.
What are the symptoms?
According to the National Institute of Neurological Disorders and Stroke (n.d.), thoracic outlet syndrome encompasses three related syndromes involving compression of nerves, arteries, and veins in the lower neck and upper chest area.
Thoracic outlet syndrome (TOS) encompasses three related syndromes involving compression of nerves, arteries, and veins in the lower neck and upper chest area, resulting in pain in the arm, shoulder, and neck. Symptoms vary based on the type of TOS:
- Neurogenic TOS: Symptoms include the "Gilliatt-Sumner hand," characterized by severe wasting in the fleshy base of the thumb. Other symptoms may involve:
- Paresthesias (tingling or numbness) in the fingers and hand.
- Changes in hand color.
- Cold hands.
- Dull aching pain in the neck, shoulder, and armpit.
- Venous TOS: Manifestations comprise:
- Pallor (paleness) in the affected arm.
- Weak or absent pulse in the affected arm, which may feel cool and appear paler than the unaffected arm.
- Numbness, tingling, aching, or swelling of the arm and fingers.
- Weakness of the neck or arm.
- Arterial TOS: Symptoms include:
- Changes in hand and finger color.
- Sensitivity to cold in the hands and fingers.
- Swelling, heaviness, tingling, numbness, and poor blood circulation in the arms, hands, and fingers.
The prognosis varies by TOS type. Most individuals experience improvement with exercise and physical therapy. However, those with vascular TOS and true neurogenic TOS often require surgery to alleviate pressure on the affected vessel or nerve. Early diagnosis and appropriate management are crucial for improving outcomes and relieving symptoms associated with TOS.
Diagnostic process
The diagnostic process for thoracic outlet syndrome (TOS) is thorough, starting with a detailed review of the patient's medical history, focusing on symptoms and any activities that exacerbate or relieve these symptoms. The physical examination is comprehensive, incorporating visual inspection of the patient's posture, observation of any skin changes or hand muscle atrophy, and palpation to detect any unusual signs.
During the physical examination, the healthcare provider performs several provocative tests to provoke symptoms characteristic of TOS. These tests include the supraclavicular pressure test, Adson test, Eden's test (costoclavicular test/maneuver), Wright test, Roos test (elevated arm stress test), and Cyriax release test. It's important to note that these tests can yield false positives, so results should be interpreted with caution.
Further diagnostic testing is essential for confirming the presence of TOS and may include a variety of imaging and functional tests. X-rays and CT scans are utilized to identify anatomical abnormalities such as cervical ribs which may contribute to compression. Additionally, Electromyography (EMG), Nerve Conduction Velocity (NCV) tests, vascular ultrasound, and angiography are employed to assess the extent of nerve and vascular involvement.
