Symptoms of Thoracic Outlet Syndrome

Symptoms of Thoracic Outlet Syndrome

What are the symptoms of thoracic outlet syndrome?

Symptoms of thoracic outlet syndrome differ for each type of TOS

Doctors classify TOS into one of three types. Compression of different vital structures determines the type of TOS. Symptoms of thoracic outlet syndrome differ for each type of thoracic outlet syndrome.

To clarify, three vital structures pass through the thoracic outlet on each side:

  • Brachial plexus
  • Subclavian artery
  • Subclavian vein
Symptoms of thoracic outlet syndrome result from compression of the brachial plexus, subclavian artery, and subclavian vein

Anatomy of the thoracic outlet

In each thoracic outlet, compression or injury of each of these vital structures may occur. Therefore, different signs and symptoms of thoracic outlet syndrome result from compression of these different vital structures. Thus, patients can suffer one or more of the three types of TOS.

What are the symptoms of thoracic outlet syndrome for each type of TOS?

Symptoms of Neurogenic TOS

Five nerve roots arise from the spinal cord on each side of the neck. Then, these nerve roots travel out of the spine to the thoracic outlet. In each thoracic outlet, the roots form a complex branching network, called the brachial plexus. Compression of the brachial plexus or tension on the brachial plexus results in neurogenic TOS. Given the complexity of the structure of the brachial plexus, patients can suffer a broad range of symptoms.

Since compression or tension affects different parts of the brachial plexus in each patient, doctors typically see a complex clinical picture.

Patients may report the following symptoms of neurogenic TOS:

  • Pain in the neck, shoulder, chest, back (between the shoulder blades, shoulder, arm or hand, on one or both sides
  • Numbness, tingling, or coldness in the arms, hands, or fingers
  • Weakness of grip, or of the arms
  • Muscle wasting in the hands

Symptoms of neurogenic TOS depend on:

  • Which part of the brachial plexus is involved
  • What structures compress the plexus (bony vs. soft tissue)
  • How long compression or tension persists
  • Whether compression or tension is persistent or intermittent
  • The degree of compression or tension.

As a result, doctors often find the diagnosis of thoracic outlet syndrome quite challenging.

Symptoms of Venous TOS

A single, large subclavian vein drains almost all of the blood from each arm. Compression of this vein can cause impaired venous drainage of the arm. When compression is severe or prolonged, it can cause damage to the inner vein wall. As a result, blood clot can form within the vein.

Patients may note the following symptoms of venous TOS:

  • Swelling and heaviness of one arm
  • Cyanosis (abnormal blue color) of the affected arm
  • Easy fatigue of the affected arm
  • New, shallow veins of the shoulder and chest
  • Shortness of breath, if blood clots travel to the lungs
  • Weakness, difficulty speaking, or other signs of stroke, in the rare event of blood clot traveling to the brain

Symptoms of Arterial TOS

A single, large subclavian artery provides most of the blood flow to each arm. Compression of this artery causes damage to the arterial wall. Damage to the inner wall can cause scar tissue and stenosis (narrowing of the artery). In contrast, damage to the full thickness of the wall can result in an aneurysm (focal ballooning of the artery). As a result of this aneurysm, a doctor may feel a pulsatile mass in the thoracic outlet. When arterial damage occurs, blood clots may form. These clots can break off and travel to distal arteries.  As a result, blood flow stops, and gangrene of the affected area may develop.

Patients may experience:

  • Coldness of the arm
  • Loss of pulse in the affected arm
  • Profound weakness
  • Pale color of the arm
  • Numbness or tingling
  • A throbbing mass between the collar bone and the neck

Blockage of arterial blood flow is a surgical emergency. The patient should be diagnosed and treated urgently to prevent loss of function or loss of limb.

Diagnosis of TOS

What are the symptoms of TOS?

Pain, numbness, and weakness of the arms and hands

Can multiple types of TOS occur in the same patient?

Yes, one patient can have multiple types of TOS at the same time. As shown above, the artery, vein, and brachial plexus pass through each thoracic outlet together. Furthermore, the mechanism of compression is similar for all types of TOS. Thus, a patient can have compression of 1, 2, or all 3 of these vital structures. In fact, many patients with neurogenic TOS have significant compression of the subclavian vein, but without a blood clot. Since this compression impairs venous drainage of the arm, swelling or edema of the arm can result. As a result, compression of the brachial plexus is magnified. In that case, treatment to relieve the venous compression helps relieve compression on the brachial plexus.

It is often difficult for a physician to distinguish these multiple compression effects. Therefore, modern imaging quite often provides this important additional information prior to treatment.