Thoracic outlet syndrome

Introduction

Introduction to thoracic outlet syndrome Thoracic outlet syndrome (TOS) is a series of symptoms caused by compression of the subclavian artery, vein and brachial plexus in the upper thoracic cavity. It is also known as anterior scalene syndrome, cervical rib syndrome, and chest. Small muscle syndrome, rib lock syndrome, excessive abduction syndrome, etc., refers to a series of upper extremity vascular and neurological symptoms caused by brachial plexus and subclavian arteriovenous compression due to some reasons. The general term is that this disease is one of the common causes of shoulder and arm pain. basic knowledge Sickness ratio: 0.0001% Susceptible people: no specific population Mode of infection: non-infectious Complications: Raynaud's disease venous thrombosis

Cause

Cause of thoracic outlet syndrome

Anatomical factors (30%):

The thoracic outlet syndrome causes ligaments due to anatomical factors. The bones and muscles are caused by compression of the subclavian vessels and brachial plexus. Clinical observations have found that people who often take heavy objects can cause shoulder muscles and ligament hypertrophy, causing compression of the neurovascular bundle. Symptoms, workers who often over-extend the upper limbs or certain sports athletes, long-term workers with shoulders extending forward, older people and middle-aged people with hunchback are prone to symptoms of thoracic outlet syndrome.

Abnormal bone mass (25%):

The cause of compression of the neural tube is abnormal bone, such as cervical rib, 7th cervical transverse process is too long, the first rib or clavicle two-legged deformity, exostosis, traumatic clavicle or first rib fracture, humeral head dislocation, etc. In addition, there are bethop muscle spasm, fibrosis; shoulder strap drooping and excessive abduction of upper limbs can cause the thoracic outlet to become narrow, resulting in compression of the subclavian blood vessels and brachial plexus, in addition to the normal movement of the upper limb as above, abduction, shoulder The part is drooping backwards, the neck is stretched, the face is turned to the opposite side, and deep inhalation can also reduce the gap of the rib lock, and the degree of compression of the nerves and blood vessels is aggravated.

Prevention

Thoracic outlet syndrome prevention

Avoid using heavy shoulders, as this will force the collarbone and increase the pressure on the chest outlet. You can also do some simple exercises to make the shoulder muscles strong. Here are four exercises, each of which is done 10 times a day. Once, repeat twice.

1. Stretch in the corner: stand in the corner, about a foot or so away, put your hands on the two walls, lean your body toward the corner, feel the neck pulled, and hold for 5 seconds.

2. Neck stretching: Put your left hand on the back of your head, put your right hand on the back, use your left hand to lean your head to the left, and the right neck has a feeling of pulling. Hold on for 5 seconds, then change hands and practice in the opposite direction.

3. Shoulder joint activity training: shrug the shoulders, then move backwards and downwards, similar to the shoulder joints to make circular arc movements.

4. Neck contraction: Hold your head straight to the ground and keep the squat position for 5 seconds.

Complication

Thoracic outlet syndrome complications Complications Raynaud's disease venous thrombosis

Early thrombosis is a cellulose platelet type, Raynaud phenomenon can occur, sympathetic nerve fiber contraction reflex can aggravate fingertip vascular occlusion, vein is compressed during excessive abduction or adduction, blood reflux stagnation and peripheral vein can be observed The pressure rises and the compression returns to normal. The repeated damage of the vein wall can develop a fibrotic-like change after inflammation. The vein is white, loses translucent state, and the caliber is obviously reduced, forming a collateral circulation. The early development trend is venous thrombosis. If the collateral circulation has not yet formed, it can cause a change in fingertip necrosis.

Symptom

Symptoms of thoracic outlet syndrome Common symptoms Fatigue fatigue lateral sensation of the shoulder arm... Hand numbness varicose sensory dysfunction carpal tunnel syndrome thoracic collapse deformity vascular murmur

In some patients, the pain is atypical, involving the front chest and shoulder areas, and even symptoms of pseudo-angina. Coronary angiography was normal in these patients, but when the ulnar nerve conduction velocity was below 48 m/s, the diagnosis of thoracic outlet syndrome was strongly suggested. Symptoms of the shoulders, upper limbs, and hands often provide clues to diagnose thoracic outlet syndrome. Symptoms of arterial compression include cold, painful, weak or prone to fatigue in the upper limbs and hand skin, and the symptoms of pain are usually diffuse. Some patients have Raynaud's phenomenon, usually unilateral, and are caused by excessive abduction of the upper limbs, head rotation, and hand weights.

Examine

Examination of thoracic outlet syndrome

1. X-ray examination: conventional X-ray film of the cervical lateral radiograph and upper chest radiograph to determine the presence or absence of cervical or upper lung tumors, clavicle or first rib deformity, X-ray examination of the cervical spine and chest Conducive to the discovery of bony abnormalities, especially the degenerative changes of the neck ribs and bones, if there is bone hyperplasia and narrowing of the intervertebral space, it is necessary to photograph the neck CT to exclude the narrowing of the spinal canal and intervertebral foramen and other lesions invading the bone. Symptoms caused by the structure.

2. Angiography: It has certain value for the diagnosis of thoracic outlet syndrome or selective surgery, but it is not a routine examination method, but a means of confirming the positive position examination. The absolute indication for angiography is suspected of having an upper extremity aneurysm and atheroma. Plaque, cervical rib compression arteries and severe arterial spasm of finger ischemia or embolism, venography showed venous thrombosis, demonstrating that the state of important collateral vessels surrounding the obstructed vein is necessary.

Diagnosis

Diagnosis and identification of thoracic outlet syndrome

diagnosis

According to the medical history, local physical examination, chest and cervical X-ray film and ulnar nerve conduction velocity measurement, the diagnosis can generally be confirmed. The differential diagnosis of thoracic outlet syndrome should consider cervical disease, brachial plexus or peripheral nerve disease, vascular disease, heart, lung, and mediastinal disease.

Differential diagnosis

1. Cervical spondylosis:

Cervical spondylosis is more common in men over 40 years old. This disease is more common in women under 40 years of age. Cervical spondylosis is mainly caused by neck and shoulder. This disease is mainly caused by hand numbness. Cervical spondylosis rarely has large and small intermuscular muscle atrophy. There is no sign of vascular compression, X-ray film of the cervical spine, and cervical MRI can help to confirm the diagnosis.

2. Syringomyelia:

The age of the disease is 20 to 30 years old, male is more common, the ratio of male to female is 3:1, the sensory disorder is separated (the pain is disappeared, the tactile presence is serious), and the atrophy and sputum reflex disappear when the cavity is enlarged and the anterior horn cells are damaged. (The dyskinesia of this disease tends to appear first than the sensory disorder, because the circumference of the motor fiber is large, easy to be stressed), although the upper limb has autonomic dysfunction, but no vascular compression signs, MRI is of great value in identifying the disease.

3. Lower motor neuron lesions - progressive muscular atrophy:

There is no sensory disturbance in the medial cutaneous nerve innervation of the forearm, the ulnar wrist flexor muscle is often damaged, the ulnar nerve conduction velocity is slowed down completely, and there are no symptoms and signs of vascular compression.

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