Thoracic Outlet Syndrome

Thoracic outlet syndrome is not uncommonly diagnosed in patients with neck pain who also have pain down the arm, tingling and numbness and cold feeling in the affected hand.
Many patients with cervical nerve root irritation will also get this diagnosis. When the diagnosis of thoracic outlet syndrome is entertained, treatment using surgery for the relief of symptoms is often discussed.

Before considering surgery, patients must be treated as conservatively as possible since most of the symptoms attributed to thoracic outlet syndrome is often caused by pain and spasm of muscles of the neck and shoulder girdle from presence of multiple level cervical nerve root irritation.

Therefore the need for conservative management must be underscored since many patients who undergo thoracic outlet syndrome surgery continue to be in the same degree of pain as before the surgery and some of them have even more pain than before the surgery.

True nerve related thoracic outlet syndrome in the general population is indeed very rare (one case per million).

Thoracic outlet syndrome involves the lower trunk of the brachial plexus, the subclavian artery and vein, or both, at any point between the base of the neck and the arm-pit (axilla). The lower trunk of the brachial plexus and the blood vessels (subclavian artery and vein) can be entrapped in the neck before the level of the scalene muscles, or between the scalenus anterior and medius muscles or beyond these muscles in the space between the clavicle and first rib (costoclavicular region) or by pressure of the pectoralis minor muscle.

In true nerve related thoracic outlet syndrome, there is wasting of the affected thumb muscles due to stretching or angulation of the lower trunk of the brachial plexus over a fibrous band. This fibrous band extends from a small cervical rib or an elongated transverse process of the C7 vertebra, to the first rib. The patients may be affected only on one side although x-ray abnormalities of presence of the cervical rib and the elongated transverse process of the C7 vertebra may be found on both sides.

Since it is the T1 nerve root that is usually angulated or stretched over this fibrous band, the hand wasting or weakness is usually found in the thumb muscles.

The thumb muscle wasting found in thoracic outlet syndrome is similar to that found in carpal tunnel syndrome. However, in thoracic outlet syndrome, the numbness of the fingers is in the last two digits (ring and little fingers) supplied by the ulnar nerve.
In carpal tunnel syndrome, complaints of numbness is primarily in the thumb, index finger, middle finger and the thumb side of the ring finger in the distribution of the median nerve.
In addition to complaints of numbness in the last two digits of the affected hand, the patient with thoracic syndrome also has complaints of numbness in the distribution of the medial cutaneous nerve of the forearm which supplies the inner aspect of the forearm.
The inner aspect of the forearm is not supplied by the ulnar nerve and sensory abnormalities in this distribution indicate abnormalities of the lower trunk of the brachial plexus.

The patient with T1 nerve root irritation from a neck problem will also complain of numbness in the inner aspect of the forearm but in T1 spinal nerve root lesions, the conduction studies of the medial cutaneous nerve of the forearm are not affected.
In thoracic outlet syndrome, there will be abnormalities of the conduction studies of the medial cutaneous nerve of the forearm.

A thorough electrodiagnostic examination is essential to differentiate carpal tunnel syndrome involvement of the median nerve at the wrist or ulnar nerve involvement at the elbow from presence of thoracic outlet syndrome.

To get a true diagnosis of nerve related thoracic outlet syndrome, these peripheral nerve entrapment syndromes must not be present. If the peripheral nerve entrapment syndromes are present, thoracic outlet syndrome diagnosis must not be entertained first.
Tightness of the muscles of the neck and shoulder girdle due to presence of multiple level cervical nerve root involvement from sudden trauma (as with auto-accidents) or insidious cumulative trauma to the neck (as with aging) can produce pain symptoms similar to that of thoracic outlet syndrome.

Tightness of the muscles is the mechanism by which pain can continue even after thoracic outlet syndrome surgery since the original pain is related to mechanical vice-like affect of tight muscles on intramuscular nerves and blood vessels. The pulling effect of the tight muscles on pain-sensitive underlying bone and joints cause additional pain.

Selective muscle activation using eToims Twitch Method to electrically stimulate motor points (trigger points) is the method of choice to produce exercise effects to tight muscles.
On locating the irritated motor point, eToims Twitch Method produces an internal stretch effect that results in relaxation of tight muscles that promotes circulation, ending pain at the areas stimulated.