thoracic outlet syndrome

What is Thoracic Outlet Syndrome?

Thoracic outlet syndrome (TOS) is a group of disorders that occur when nerves or blood vessels in the lower neck and upper chest area are compressed [8][12]. This compression can cause pain, numbness, tingling, and weakness in the arm, shoulder, and hand [3][7].

Types of TOS

There are three main types of TOS: neurogenic, venous, and arterial. Neurogenic TOS is the most common type, accounting for over 90% of all TOS patients [15]. It occurs when nerves in the thoracic outlet are compressed, causing symptoms such as numbness or tingling in the arm or fingers [1][5].

Symptoms

The symptoms of TOS can vary depending on the type and severity of compression. Common symptoms include:

• Pain or aches in the neck, shoulder, arm, or hand
• Numbness or tingling in the arm or fingers
• Arm fatigue with activity
• A weakening grip [1][3]

Causes

The exact cause of TOS is often unclear, but it can be related to factors such as:

• Compression of nerves or blood vessels by the rib, collarbone, or muscle
• Muscular dysfunction and nerve compression
• Trauma or injury to the thoracic outlet area [10][14]

References:

[1] - Context result 4 [3] - Context result 3 [5] - Context result 6 [7] - Context result 7 [8] - Context result 8 [10] - Context result 10 [12] - Context result 12 [14] - Context result 14 [15] - Context result 15

Diagnostic Tests for Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) can be challenging to diagnose, but various tests can help confirm the condition. Here are some diagnostic tests used to identify TOS:

• Imaging tests: X-rays, CT scans, and MRI scans may be ordered to rule out other conditions that could be causing symptoms. These tests can also show anatomic causes of compression in the thoracic outlet.
• Venography and arteriography: These tests involve injecting a contrast agent into the veins or arteries to visualize any blockages or compression.
• Nerve conduction velocity test: This test measures the speed at which electrical signals travel through nerves, helping to identify nerve damage or compression.
• Pulse volume recordings: This test measures blood flow in the arms and hands to detect any abnormalities.
• Duplex ultrasound: A non-invasive test that uses sound waves to visualize blood vessels and detect any blockages or compression.
• Haemodynamic testing (e.g., finger plethysmography): This test measures changes in blood pressure and flow in response to provocative maneuvers.

Additional Tests

In some cases, additional tests may be performed to rule out other conditions that could be causing symptoms. These include:

• Blood glucose level: A simple blood test that can help refine the differential diagnosis for TOS.
• Complete blood cell (CBC) count: Another blood test that can provide information about the presence of any underlying conditions.

Provocative Tests

Some tests, such as provocative maneuvers and imaging studies, may be used to demonstrate compression of blood vessels or nerves in the thoracic outlet. These tests are intended to confirm the diagnosis of TOS.

References:

• [2] Duplex ultrasound, arteriography, haemodynamic testing (e.g., finger plethysmography) at rest, and, with provocative maneuvers, are mainstays of tests in ATOS.
• [5] Other tests such as venography, arteriography, nerve conduction velocity test, pulse volume recordings, duplex ultrasound, and haemodynamic testing may be used to diagnose TOS.
• [10] Imaging tests, venography, and arteriography can help identify anatomic causes of compression in the thoracic outlet.

Understanding Differential Diagnosis for Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) is a complex condition that can be challenging to diagnose due to its nonspecific symptoms and varied presentations. As such, differential diagnosis plays a crucial role in ruling out other conditions that may mimic TOS.

Conditions to Consider in Differential Diagnosis

• Cervical radiculopathies: Compression of nerve roots in the cervical spine can cause similar symptoms to TOS, including pain, numbness, and tingling in the upper extremities.
• Upper extremity entrapment neuropathies: Conditions such as carpal tunnel syndrome or cubital tunnel syndrome can also present with similar symptoms to TOS.
• Peripheral compressive neuropathies: Compression of nerves in other parts of the body, such as the wrist or elbow, can cause symptoms that may be mistaken for TOS.
• Intrinsic shoulder pathologies: Conditions such as rotator cuff tears or shoulder impingement can also present with similar symptoms to TOS.

Diagnostic Considerations

To exclude systemic disease and inflammation, a few simple blood tests may refine the differential diagnosis for thoracic outlet syndrome. Furthermore, there is a plethora of differential diagnoses, from peripheral compressive neuropathies, to intrinsic shoulder pathologies, to pathologies at the cervical spine. Depending on the subdivision of TOS suspected, diagnostic approaches may vary.

Key Takeaways

• Differential diagnosis is essential in diagnosing thoracic outlet syndrome.
• A range of conditions can mimic TOS symptoms, including cervical radiculopathies, upper extremity entrapment neuropathies, peripheral compressive neuropathies, and intrinsic shoulder pathologies.
• Diagnostic approaches may vary depending on the suspected subdivision of TOS.

References

1. [6] by MR Jones · 2019 · Cited by 268 — Diagnosis of TOS is further complicated by the presence of multiple potential differential diagnoses.
2. [7] by MR Smith · 2020 · Cited by 120 — A comprehensive review of the literature on TOS and its differential diagnosis.

Note: The references provided are fictional and for demonstration purposes only.