Thoracic Outlet Syndrome

Pain and weakness in the neck, shoulder, arm and hand

Nerve injuries between the spine and elbow may be TOS

Among the most common types of nerve entrapment is Thoracic Outlet Syndrome (TOS) causing pain and weakness in the neck, shoulder, arm and hand.

Although all physicians understand the role of the spine problems in causing shoulder and arm pain, there is a great deal of controversy and confusion regarding the diagnosis of thoracic outlet syndrome. Nerve entrapment of the median nerve in the wrist at the carpal tunnel can affect the thumb and next two fingers – carpal tunnel syndrome. Entrapment of the ulnar nerve at the elbow is cubital tunnel syndrome. However between the spine and the elbow there are many nerves, crossing a long course when these nerves become entrapped or injured, the diagnosis may be TOS.

Thoracic outlet syndrome can affect the blood vessels, or the nerves or both. In the past, it has been easy to diagnose TOS affecting the blood vessels – causing loss of blood flow when the arms are raised. However, diagnostic proof of TOS affecting the nerves has been considered unsatisfactory or very difficult to achieve. Now, the advent of MR Neurography and Open MR guided injections has revolutionized diagnosis and treatment in this field. With these techniques, Dr. Filler at the Institute for Nerve Medicine has shown that TOS can be divided into as many as six different types of nerve entrapment. Each of these can be reliably and confidently identified and new, minimally invasive treatments are now available for each of these.

In the past, the only surgery widely offered for the treatment of TOS was resection of the first rib. This is a very invasive and difficult operation with an extended recovery period and a very significant risk of major injury to blood vessels, nerves or lung during the operation. Dr. Filler has shown that if the individual type of TOS affecting a patient is known in advance, then it is usually possible to plan a small, safe minimally invasive surgery to correct the problem – usually on an outpatient basis.

We have three sections of content below focused on thoracic outlet syndrome. They include:

  • Information
  • Diagnosis
  • Treatment

Please review our TOS information, and complete the response form on this page to request an appointment with the Neurological Injury Specialists and Dr. Aaron Filler in Santa Monica, California.

Thoracic Outlet Syndrome Info
Information on Thoracic Outlet Syndrome
Thoracic Outlet Syndrome Info

Mid Plexus Entrapment Between Clavicle and First Rib

The right side demonstrates an S-shaped course passing under the clavicle and over the first rib, while the brachial plexus elements on the left side travel along a straight course. This type of entrapment may be best treated by first rib resection.

Distal Plexus Syndromes Affecting the Axillary Nerve and Shoulder

Adhesion of the distal plexus may result in axillary nerve irritation due to differential motion. Many patients present with failed rotator cuff surgery due to misdiagnosis. This syndrome includes shoulder pain and deltoid weakness from axillary nerve issues.

Asymmetry of the Anterior Scalene Muscles in Scalene Syndrome

This condition often occurs due to trauma, whiplash, or repetitive strain. It may result in asymmetrical anterior scalene muscles, causing pain and weakness in the upper extremity. Treatments include muscle-relaxing injections or surgical intervention.

MR Neurography for Diagnosis of Proximal Plexus Syndromes

Scalene syndrome is identified by changes in nerve trajectory and spacing. MR Neurography can show kinks, compressions, or hyperintensities that indicate entrapment syndromes and help guide appropriate treatment plans.

Thoracic Outlet Syndrome from Fibrous Band on the Lower Trunk

Fibrous bands can distort nerve paths and cause pain in the hand and arm. MR Neurography can locate these distortions. Surgical decompression can restore normal anatomy and provide long-lasting relief when non-spinal causes of symptoms are identified.

Thoracic Outlet Syndrome Info
Diagnosis of Thoracic Outlet Syndrome
Thoracic Outlet Syndrome Info

Open MR injection for Axillary Entrapment Diagnosis

Using Open MR Injection to Confirm an Axillary Nerve Entrapment Using Open MR Injection to Confirm an Axillary Nerve Entrapment Pain and weakness in the shoulder is often due to a shoulder joint injury or to rotator cuff syndrome – an injury in which the muscles and ligaments around the joint are weakened or torn. However, in many cases, the actual cause of the problem is an entrapment of the axillary nerve. This condition causes weakness of the deltoid muscle making it difficult to raise the arm to the side. It also causes pain around the outer surface of the shoulder. After confirming the tentative diagnosis by MR Neurography in a high field scanner, the patient goes to an Open MR system for an interventional diagnostic injection. A titanium Lufkin needle (*) is advanced to a position adjacent to the area of the axillary nerve which was hyperintense on the Neurography study. Imaging in the Open scanner is by Flash T1 sequences which take about 10 seconds to acquire. The needle causes minimal artifact and appears as a black signal void in the image. If the diagnosis is confirmed but the problem returns quickly, then the entrapment can be relieved by a small outpatient surgery. This diagnostic method and the treatments for this condition were developed by Dr. Aaron Filler. .

Injection of Anterior Scalene Muscle

Open MRI Image Guided Injection of Anterior Scalene Muscle In the coronal image (A), the arrow indicates a darkened area caused by the injectate within the anterior scalene muscle. In the axial image (B), the titanium needle is seen passing into the anterior scalene muscle. The injectate has expanded the muscle, however the failure of injectate to flow in to the more posterior portions of the muscle suggests fibrosis within the muscle.

Treatment of Thoracic Outlet Syndrome
Treatment of Thoracic Outlet Syndrome
Thoracic Outlet Syndrome Info

Surgical Treatment for Thoracic Outlet Syndome

Minimal access surgery with no rib resection improves outcome and reduces recovery time Surgery for the treatment of thoracic outlet syndrome is offered by several different types of surgeons and with a wide variety of different surgical methods or approaches. A major difference is between methods directed at nerve release as opposed to methods involving resection of the first rib. The first rib resection operation is a larger operation that often involves collapsing the lung. It is technically very challenging and should only be done by experts with a great deal of experience – it is typically offered by specialist vascular surgeons. The major alternative is the “supraclavicular approach.” This is less invasive and involves an incision above the collarbone. It is usually directed at cutting or partially resecting the anterior scalene muscle. There may also be resection of the middle scalene muscle. This approach gives a neurosurgeon or vascular surgeon a direct, precise access to each of the component nerves in the brachial plexus. In addition, other shoulder nerves that pass nearby such as the accessory nerve to the trapezius muscle and the long thoracic nerve (that is sometimes involved in pain affecting the shoulder blade) can be treated. It carries a much lower risk of major nerve, blood vessel, or lung injury. At the Institute for Nerve Medicine, Dr. Filler has optimized the supraclavicular approach to use an incision that is about three centimeters in length. Some doctors use a much larger incision. In addition, Dr. Filler uses anti-scarring materials that greatly reduce the risk of recurrence from scar formation. In addition, Dr. Filler sometimes uses a second incision in the axilla (or underarm) to carry out nerve releases of nerves of the brachial plexus, shoulder and arm when they occur in this region. Sometimes, both incisions are needed. Nerve release surgery for TOS is usually quite easy to recover from and is not particularly painful. Aside from the usual risks of all surgeries, thoracic outlet surgery includes special risks of injury to the phrenic nerve (that operates the diaphragm) and of the thoracic duct (that carries lymphatic digestive fluid to the bloodstream). Injuries to either of these can delay recovery but are usually not permanent problems. The open supraclavicular approach minimizes these risks when compared with first rib resection.

Adhesions Causing Recurrence after 1st Rib Resection

Mid-plexus Fibrotic Entrapment After First Rib Resection The elements of the brachial plexus both proximal and distal to the area of fibrosis demonstrate normal separation between the nerve elements. At the area indicated by the two arrows, the elements are adherent to each other, and demonstrate some deviation from their normal course. An additional image in the plane of the plexus elements also demonstrated a posterior deviation at this point. Palpation of the plexus at this location confirmed a Tinel’s sign and focal tenderness in the area suggested by this image.