Delayed Diagnosis of Thoracic Outlet Syndrome

  • TOS Case Studies-Delayed Diagnosis of Thoracic Outlet Syndrome

A 50 year-old woman fell down a flight of stairs at work. Pain, numbness and tingling developed rapidly in her left arm, and then in her right arm.

The patient sought help from a series of doctors. None of these diagnosed a reason for the patient’s symptoms. The patient continued to seek help, but several additional doctors told the patient she was depressed. Other doctors told the patient her pain was more likely due to emotional causes than to physical causes, given that no test had shown any pathology.

Fortunately for the patient, she eventually found a neurologist who suspected the diagnosis of thoracic outlet syndrome. This neurologist has extensive experience diagnosing thoracic outlet syndrome. He felt that the patients physical exam findings were strongly suggestive of thoracic outlet syndrome, and he ordered a NeoVista® MRI examination.

First, the MRA (MR angiogram) proves marked extrinsic compression of the left subclavian artery (first image below). A second image from the MRA shows an aneurysm of the subclavian artery just distal to the point of maximum compression. Severe narrowing of the artery is known to create turbulent, high-velocity blood flow. Under the right conditions, this causes damage to the arterial wall, resulting in an aneurysm. Left unaddressed (or unknown without this imaging test), blood clots can form in the aneurysm, and cause distal gangrene.

Note the dark background of the MRA. This has been done intentionally, to maximize the signal from the arteries. Unfortunately, we have no way of knowing what structure is causing the arterial compression from these images alone.

TOS Case Studies-Delayed Diagnosis of Thoracic Outlet SyndromeTOS Case Studies-Delayed Diagnosis of Thoracic Outlet Syndrome

Second, the MRI clearly demonstrates small to moderate bilateral cervical ribs. None of the patient’s medical records showed that her doctors were aware of these extra ribs.

Third, the MRI shows focal marked thickening of the left brachial plexus as it crosses the cervical rib.

The MRI images below demonstrate these findings. Note that the bright arteries previously seen on the MRA are now black, and almost impossible to assess.

TOS Case Studies-Delayed Diagnosis of Thoracic Outlet SyndromeTOS Case Studies-Delayed Diagnosis of Thoracic Outlet Syndrome

Fourth, provocative imaging with the patient’s arms over her head proves marked compression and angulation of the brachial plexus at the point of thickening. The MRI images below are performed with the patient’s arms raised. Compared to the images above (with the arms down) these images show how arm motion causes compression of the brachial plexus.

TOS Case Studies-Delayed Diagnosis of Thoracic Outlet SyndromeTOS Case Studies-Delayed Diagnosis of Thoracic Outlet Syndrome

Key Points:

  • Multiple types of TOS may be present in the same patient.
  • MRI and MRA in combination can demonstrate pertinent pathology underlying all forms of thoracic outlet syndrome. X-rays would have shown the cervical ribs, but would not have show the arterial aneurysm or brachial plexus compression.
  • Patients with chronic pain may suffer from depression, or appear overly emotional. The presence of depression does not exclude underlying pathology.
  • This patient required a specialized surgical approach, to decompress the brachial plexus and subclavian artery, and to repair the brachial plexus. The NeoVista® MRI examination changed the patient’s diagnosis and treatment plan.

NeoVista answers the important questions

This case is one example of the value that NeoVista® can bring to your doctor. No substitute. No compromise.

By |2019-01-23T05:51:26+00:00January 1st, 2019|Categories: TOS Case Studies|Tags: , , , , |0 Comments

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