Thoracic outlet syndrome: what is it, symptoms, treatment, prognosis

What is thoracic outlet syndrome?

Thoracic outlet syndrome (SGV, or neurovascular compression syndrome) Is a condition in which the hands complain of pain, numbness, tingling, and weakness. The reason is compression (compression) in the neck of the nerves and blood vessels going to the arm. Depending on which structure is compressed, there are three types of SGW: 1. Neurogenic GBS nerve compression accounts for 95% of all GBV 2 patients. Venous GBV compression of the main vein is 4% of all patients with GBV 3. Arterial GBS compression of the basilar artery is less than 1% of all GBS patients. 4. Vascular GBS is a term that is sometimes used, but this type of GBS does not exist. This term refers to GBS due to compression of an artery or vein (arterial or venous GBS). Use the appropriate terms, arterial or venous, and discard the term vascular. The three types of GBS are very different from each other. Each will be described separately below.

Signs and symptoms

Thoracic outlet syndrome is manifested by pain, weakness, numbness, and tingling in the arm and hand. In addition, neck pain and headache in the back of the head are common.

Venous GBS, also known as Paget-Schrötter disease, is manifested by hand swelling, blue discoloration or darkening, and a feeling of fullness or pain in the hand.

Arterial thoracic outlet syndrome manifests as cold, numbness, tingling, pain, and discoloration of the fingers or the entire hand. Spasms of the forearm and hand during activity (lameness) are common. The pain usually affects the hand and arm, but not the neck or shoulder.

Causes and risk factors

Neurogenic thoracic outlet syndrome most often occurs as a result of neck injuries, whiplash or repetitive stressful injuries at work, which are the most common symptom-causing events. The injury results in over-stretching of the muscles in the neck, which are healed by the formation of scar tissue in the muscle. This, in turn, puts pressure on the nerves in the arm, which causes symptoms.

Venous neurovascular compression syndrome is often caused by strenuous use of the arm that irritates the main vein in the arm (subclavian vein) behind the collarbone. The pressure on the vein is due to differences in normal anatomy. Most people have enough room for the main vein to run from hand to heart. However, some people are born with a very narrow space through which a vein passes. It is these people who can develop blockage and blood clots in a vein due to excessive activity in the arms and shoulders.

Thoracic outlet syndrome is caused by a clot in the arm (subclavian artery) just behind the collarbone. Even when a clot (blood clot) forms, most people do not develop symptoms until after the clot breaks up into small pieces that run down the arm, blocking arterial circulation in the elbow, or hand. Clotting occurs due to changes in the artery as a result of a congenital extra rib called the cervical rib or abnormal first rib.

Symptomatic disorders

Symptoms of the following conditions may be similar to those of thoracic outlet syndrome. Comparisons can be useful for differential diagnosis:

Pectoralis minor syndrome (Wright-Mendelovich syndrome) Is a condition that causes pain, numbness, and tingling in the arm and hand. The disorder often coexists with thoracic outlet syndrome (GBS) but can also occur on its own. Symptoms are similar to those of GBS: pain, weakness, numbness, and tingling in the arm and hand. But pectoralis syndrome also has pain or tenderness in the chest wall below the collarbone and often in the armpit as well. As with GBS, pain can be higher than the scapula in the back as well as in the neck. Although theoretically it can touch the nerves, veins and arteries of the arm, as with GBS, it rarely affects the vein and artery. First of all, when the disorder is, pressure is exerted on the nerves.

It is caused by compression in the pectoralis minor (located just below the collarbone), which is located just below the pectoralis major muscle in the front of the ribcage, below the breast. The condition is often caused by a neck injury or over-stretching of the shoulder. It is important to note that not only are the symptoms similar to thoracic outlet syndrome, but the two conditions often coexist.

A hallmark of Wright-Mendelovich syndrome is soreness in the chest area just below the collarbone, as well as soreness in the armpit. The best test for Wright-Mendelovich syndrome is the blockade of the pectoralis minor. Physical therapy is the initial treatment. Cutting the tendon of the pectoralis minor muscle at the point of attachment to the bone below the clavicle (coracoid process) is the main surgical method of treatment.

In children, pectoralis syndrome is often caused by sports competitions in which involves the use of the hand, such as swimming, baseball, volleyball and other similar activities activities.

Diagnostics

Thoracic outlet syndrome is diagnosed by provocative actions to identify (or provoke) symptoms. These actions place the neck and arms in specific positions that put stress on the nerves in the arm and cause symptoms of pain, numbness, and tingling in the arm, shoulder, and neck. Some of these actions have proven to be unreliable, since positive responses are found in many healthy people. These include the Adson test, the Roos test, and the Wright test. Other provocative actions that provide greater reliability and are rarely positive in healthy people people include turning the neck or tilting the head to one side, which causes symptoms on the opposite side side. Another provocative method is extending one arm to the side, flexing the wrist upward and tilting the head in the opposite direction (called the upper limb tension test).

Few tests can help diagnose neurogenic syndromes. The most useful test is scalene muscle block. It is performed by injecting a small amount of local anesthetic directly into the scalene muscles of the neck. A positive response is an improvement in symptoms at rest, as well as with provocative maneuvers that occur within one or two minutes after injection.

Nerve tests, such as EMG / NCV tests, are usually normal. The only exception is that in people who have an extra rib (cervical rib) plus weakness of the arm and muscle atrophy of the hand, usually abnormal nerve tests occur, indicating anomalies of the ulnar nerve. However, the recent introduction of a new nerve test, the medial anterior cutaneous nerve test, has proven to be very beneficial, especially in people who have symptoms in only one arm. In these people, a good hand serves as a starting point for comparing a symptomatic hand.

X-rays are usually normal, but should be done as they may show an extra rib on the neck. Although less than 5% of patients with neurogenic syndrome have an extra rib, its presence helps confirm the diagnosis. Newer diagnostic tests that have yet to prove themselves include MRI of the brachial plexus and injections of dye around the brachial plexus (neurography). The problem with recent tests is that many healthy people show abnormalities in these studies.

Arteriography is useful in diagnosing arterial GBS but should not be used to diagnose neurogenic GBS. The reason is that in healthy people, narrowing of the artery can be found when the arm is raised. This makes the demonstration of hand artery narrowing in patients with nerve symptoms useless in diagnosing a nerve problem.

Recognizing arterial and venous GBS is usually not that difficult, as there are objective tests to confirm the diagnosis and very few other conditions that resemble them. However, neurogenic GBS, which is the most common type of GBS, is more difficult to diagnose because other neurogenic conditions mimic it. An understanding of the anatomy of the nerves of the hand is helpful. The nerve is like a telephone wire running from a telephone pole down the street to your home. Damaging the wire anywhere in its path will lead to the same result, namely the phone disconnecting. The nerves of the hand start from the neck and extend to the fingers, like a single wire. Pressure on the nerve anywhere along its length will cause the same symptoms in the arm, namely numbness, tingling, pain, and weakness. The pressure points at which this can occur are in the wrist causing carpal tunnel syndrome, under the collar bone, under the chest muscle causing small chest syndrome, in the side of the neck, causing thoracic outlet syndrome, or in the cervical spine, caused by cervical disc disease or arthritis of the cervical spine spine. Therefore, pressure at any of these points produces symptoms similar to neurogenic GBS, and each of these conditions must be looked for by physical examination and checked using diagnostic tests nerves.

Venous GBS is fairly easy to recognize by swelling the whole arm and hand. Superficial veins that lie just under the skin are more visible on the affected arm, shoulder, and above the chest wall of the affected side.

The only tests that help diagnose venous obstruction are Doppler or duplex examination and venography (dye injection into a vein in the arm).

Arterial GBS is recognized when the affected arm is cold and pale. Pulse at the wrist is usually low or absent.

Tests useful in diagnosing arterial GBS are non-invasive recording of pulse volume (non-invasive laboratory testing of blood vessels) and arteriography (dye injection into an artery).

Standard treatments

Basically, there are two ways to treat thoracic outlet syndrome: a nonsurgical one, which is called conservative, and a surgical one. Neurogenic GBS is always treated first with physical therapy. For many patients, this treatment helps, and in the future nothing is required.

Neurogenic GBS can be treated surgically if conservative therapy fails and the patient still has significant symptoms. Surgery involves relieving pressure from the nerves on the arm by removing the scalene muscles in the neck, removing the first rib, which requires removal of the scalene muscles, or removal of the scalene muscles and the first rib. The choice of operations depends on the experience of the surgeon, since each of these operations has approximately the same probability of success.

Venous GBS is initially treated with thrombolytic drugs and anticoagulants (blood thinning drugs). After the original blood clot dissolves, surgery may be needed to treat the underlying condition that caused the clot to prevent it from recurring.

Venous GBS is treated surgically by resecting the first rib, including removing the ligaments surrounding the subclavian vein. In patients with a completely blocked vein, a bypass bypass is sometimes performed to restore venous circulation in the arm.

Arterial GBS does not require non-surgical treatment. Physiotherapy does not help.

Surgery for arterial GBS includes two stages: first, removal of an extra or abnormal rib; then the damaged artery is excised and circulation is restored by suturing the two ends of the artery together if the aneurysm was small, or with an arterial graft.