Diagnosis of Thoracic Outlet Syndrome

Signs and Symptoms of Thoracic Outlet Syndrome

Onset of symptoms of thoracic outlet syndrome (TOS) is usually very vague. Initially the patient may ignore the symptoms because they are mild and/or intermittent. As time progresses, symptoms may increase in frequency and intensity to the point where the patient seeks medical attention, typically when they achieve no relief from moving their arm, changing position, or taking over-the-counter medication. The patient may or may not remember a precipitating event, such as trauma.

Symptoms that patients typically describe when they seek medical care include:

  • Neck/shoulder pain that may spread to the upper arm and forearm
  • Pain radiating down the arm
  • Dull, aching pain in the shoulder and/or arm
  • Numbness/weakness along the forearm, hand, and little finger
  • Paresthesia (burning, prickling or tingling sensation)
  • Headache involving the occipital (back of the head) or orbital (around the eyes) areas
  • Anterior chest wall pain (pseudoangina)

Clear cut cases of vascular TOS are somewhat easier to identify than neurogenic TOS. Symptoms with which the patient may present to the physician (in addition to those listed above) that are indicative of vascular TOS include:

  • Swelling of the arm/hand
  • Coldness in the hand/finger
  • Bluish color of the hand/finger
  • Wasting (atrophy) of the hand (in severe, chronic cases of TOS)

Neurogenic signs are much harder to diagnose definitively as thoracic outlet syndrome. In severe cases, (e.g., hand muscle atrophy), it may be possible to clearly identify compression of the brachial plexus and, although surgery is performed, it does not always resolve the symptoms. For patients who present with sensory symptoms, (e.g., paresthesia, numbness, or pain) there is no test to definitively reach a diagnosis of TOS. Therefore, some health care providers feel that thoracic outlet syndrome is overdiagnosed while others think it is underdiagnosed. Both, however, agree that:

  • No single test is reliable to definitively determine a diagnosis of TOS
  • Electrodiagnostic studies are typically normal
  • Surgery results in little improvement of symptoms

Symptoms follow the pattern of deterioration of the nerve. The aching is related to the muscles that are innervated by the compressed nerve. The compression of nerves is accompanied by complaints of intermittent paresthesia and, finally, numbness. When tested, patients will initially exhibit symptoms only during provocative tests of arm positions and, as the deterioration continues, patients can maintain the elevated position for less and less time due to intense discomfort. Deterioration to the point of muscle atrophy of the hand is rare.

Symptoms of Neurogenic Thoracic Outlet Syndrome

  • Pain in the neck on the affected side. The pain may radiate up to the head and cause hemicranial headaches (headache on one side of the head) or headaches in the occipital region (lower back of the head). Pain may also radiate into:

    • mandible (jaw)
    • face
    • temple

  • Pain that may radiate posteriorly to the back, across the shoulders, upper chest, and down the outer arm

  • There may be numbness and tingling of the ear, cheek, back of the shoulder, or outer arm
  • Discomfort around the shoulder, front and/or back
  • Pain radiating down the arm and into the hand
  • Dull aching pain in the arm
  • Weakness, tingling or numbness in the fingers
  • Pain spreading up the side or back of the neck and to the back of the head (occipital area)
  • Severe headaches which may radiate over the top of the skull (headaches are usually related to arm movement)
  • Paresthesia may occur in the presence of pain or alone
  • Arm may feel like it's "going to sleep" when elevated

Symptoms typically intensify following exertion (e.g., after exercise) and/or elevation of the affected arm. Some patients report that symptoms are worse at night following a day of heavy use of their arm. Symptoms can also be initiated following positional changes of the arm, including:

  • Reaching out for something
  • Activities during which the arm is raised for an extended period as in painting, using a hair dryer, applying makeup, or changing overhead bulbs.
  • Heavy lifting in which the arm is pulled downward
  • Sleeping with the arm above the head and elbows flexed

As thoracic outlet syndrome advances, the patient may experience weakness of the hand and loss of dexterity. In advanced cases, there may be muscle atrophy and reduced use of the arm but no paralysis. It is rare that TOS deteriorates to this extreme situation.

Symptoms of Vascular TOS

Arterial TOS

In arterial TOS, the patient may also not be mindful of early symptoms. The patient may complain of heaviness or weakness of the arm and may experience numbness or paresthesia. Patients may also experience headaches at the back of the head (occipital) or in and around the eyes (orbital). Typically, symptoms are exacerbated by using the arm especially if it involves any overhead positions. Later symptoms associated with arterial TOS include:

  • Pallor (paleness of the limb)
  • Erythema (skin turns red)
  • Affected arm may be cold
  • Fatigue of the arm with exercise

Early emboli (clots no longer attached to the wall of the blood vessel and can travel in the blood stream) usually do not lead to significant complications. But chronic embolic episodes can lead to ischemia (lack of oxygen supply) of the limb and progression of tissue damage. If the diagnosis is delayed over a long period, severe symptoms can develop (e.g., limb-threatening ischemia and other thromboembolic complications). At this point, surgical management becomes difficult, especially if the clots have traveled down the arm and are blocking smaller blood vessels. Advanced cases that cannot be managed by surgery may result in amputation of the limb. This is very rare.

Venous TOS

The unique symptoms associated with venous TOS include:

  • Swelling of the entire affected arm, forearm, and hand
  • Edema
  • Cyanosis
  • Venous distention
  • Discomfort of the arm that is aggravated with activity or exercise

Patients may or may not experience pain with this condition. The affected limb may have a diameter 1-3 inches greater than the unaffected arm. Visible superficial veins may also be present. Venous thrombosis may develop at the location of the compression. The diagnosis of venous TOS is often delayed until there is evidence of thrombosis (sudden edema with cyanosis and limb discomfort) at which point treatment must be initiated immediately in order to prevent complications.

Although vascular TOS is often seen in young patients who are physically very active particularly with their arms, at the time of diagnosis they are approximately 10-15 years older than those with neurogenic TOS since vascular symptoms are frequently overlooked until they become severe.