03/03/2016
Thoracic Outlet Syndrome
Thoracic Outlet Syndrome (TOS) involves the compression at the thoracic inlet, ( known clinically as the superior thoracic outlet), resulting in excessive pressure placed on the neurovascular bundle as it passes between the anterior and middle scalene muscles. It can affect one or more of the nerves that innervate the upper limb and/or blood vessels as they pass between the chest and upper extremity. Usually affected are the brachial plexus and the subclavian artery, and to a lesser extent, the subclavian vein.
TOS may result from a positional cause, for example, by abnormal compression from the clavicle (collarbone) and shoulder girdle on arm movement. There are also several static forms, caused by abnormalities, enlargement, or spasm of the various muscles surrounding the arteries, veins, and/or brachial plexus, a fixation of a first rib. A Pancoast tumor, (a rare form of lung cancer in the apex of the lung) can lead to thoracic outlet syndrome in the progressive stages of the disease. The most common causes of thoracic outlet syndrome include physical trauma from a car accident, repetitive strain injury in a work situation such as frequent use of a keyboard with poor ergonomics. Sports-related activities, and anatomical defects such as having an extra rib may cause it to develop as well. In pregnancy, a woman with an anatomically narrow superior thoracic may find herself suffering from TOS symptoms for the first time. As well, joints loosen during pregnancy especially during the last trimester, making it easier to develop bad posture which can help set the stage for TOS development.
Common orthopedic tests used to diagnose the problem include the Adson's test, the Costoclavicular Maneuver, and the "Hands-Up" test or "EAST" test. Careful examination and X-rays are required to differentially diagnose between the positional and static etiologies, i.e. first rib fixations, scalene muscle spasm, or a cervical rib or fibrous band.
There are three types of thoracic outlet syndrome: nerve compression, vascular compression and neurovascular compression, while nerve compression is the most commonly seen:
1. Brachial plexus symptoms: pain, numbness, paresthesia, usually on fingers and inner side of the arms, may also experience shoulder and neck pain spreading towards the arms. In severe cases, patients may experience loss of sensation, movement disorder and muscle atrophy.
2.Subclavian artery symptoms: pain, swelling, soreness, swelling distal cyanosis
3. Subclavian vein symptoms: pain, swelling, soreness, swelling distal cyanosis
The diagnosis of thoracic outlet syndrome is suggested by the above symptoms and supported by findings of the doctor during certain examinations. Adson’s maneuver, Halstead maneuver, Roo’s test, Allen maneuver and Wright’s test help locate patients’ oppressions.
The key to successfully easing TOS symptoms is an early diagnose. Once the nerves have been compressed for a long period of time, the nerve fibers can be irreversibly damaged, which may lead to vasomotor disorders, blood vessel wall thickening, and thrombosis. It has been shown that it may take as little as 2 grams of pressure on a nerve to result in changes to the way it functions.
Thoracic outlet syndrome is very common among people with occupations or activities that require repetitive or strenuous postures, especially seen with people who use computer a good deal. TOS is often misdiagnosed for cervical spondylitis or rheumatism.
A patient, Mrs. Wang worked at a job for over ten years that required her to use a computer continually. She presented at our clinic suffering pain, numbness and coldness of her right shoulder, arm and hand for over a year, and had been misdiagnosed with cervical spondylitis, rheumatism, and neuritis. I then performed Adson’s maneuver and Allen maneuver on her; both of which were seen to be positive. Palpation and observation showed serious tenderness around the scalene group, a clear sign of TOS symptoms. After only four sessions of acupuncture treatments, her arm pain and numbness was completely relieved. Ms. Wang’s case shows that a correct diagnosis is a prerequisite for efficacy of the therapy.
Acupuncture treatment has a noticeable result treating TOS; commonly used acupoints are Tianliao, Futu, Tianding, Quepen, Hegu, Waiguan. Professional acupuncture treatments applied at accurate acupoints will have good healing results. Acupuncture has been shown to have immediate effects in relieving scalene group congestion, edema and spasm.
