Thoracic outlet syndrome is a relatively rare disorder in which the nerves of the brachial plexus and/or subclavian blood vessels are compressed as they pass from the neck down to the arm. This syndrome usually results from excess pressure placed on them by either muscles in the neck, called the anterior scalene muscles, or bony structures of the thoracic outlet. Patients with thoracic outlet syndrome will most often complain of pain that extends down the arm, usually in the hand - specifically, the fourth and fifth fingers (the ring finger and pinky only) - but can also involve the forearm and upper arm. Most times, this pain may be a sharp burning or aching and cause numbness or tingling.
Thoracic outlet syndrome can affect adults and children of all ages and gender though it tends to not become prevalent until the teenage years and into adulthood. It can also develop spontaneously in middle age when it is seen more commonly in women than men because of poor muscular development and posture. It can be common amongst those who are tall and thin, as with those who have Ehlers-Danlos Syndrome. It may also affect those who participate in sports requiring repetitive motions of the arms and shoulders. This includes swimmers, volleyball players and other athletes competing in baseball and weightlifting. Sports are not the only activity that may result in this syndrome. The repetitive motions required to play stringed instruments and to work in carpentry and construction can also cause thoracic outlet syndrome.
Diagnosis of Thoracic Outlet Syndrome
The WVU Medicine Children’s Brachial Plexus and Peripheral Nerve Clinic is well-versed in diagnosing thoracic outlet syndrome. During a neurological exam, the arm is placed in different positions so symptoms can be reproduced. This helps us determine whether the syndrome is caused by compression of the nerves of the brachial plexus (neurogenic) or by the compression of the subclavian artery or vein (vasogenic), which are in the neck.
In this kind of exam, changes in sensation, motor function and adequate blood flow (decrease in the pulses when arms elevated above your head) can sometimes be seen. Imaging and other studies may also be necessary. X-rays and computerized tomography (CT) scans can be used to evaluate for congenital issues like the presence of cervical or other anomalous ribs which can compress the nerves. Magnetic resonance imaging (MRI) especially if MRA (MR arteriography) or MRV (MR venography) can also be useful because it can show variation/compression in the blood vessels or nerves, which is evidence of compression particularly when the imaging is obtained in the positions that cause the symptoms (i.e., arms raised above the head).
Treatment of Thoracic Outlet Syndrome
Treatment of thoracic outlet syndrome most often involves physical/occupational therapy and medicines for symptomatic pain relief. However, in 10-20 percent of cases that do not improve with those treatments, thoracic outlet surgery can be used to increase the space by which the blood vessels and nerves passed through the thoracic outlet.
Surgery for Thoracic Outlet Syndrome
Surgery for the treatment of thoracic outlet syndrome involves creating more room for the nerves and/or blood vessels to pass from the neck to the arm underneath the clavicle/collarbone. This may involve removing scar tissue, detaching parts of the scalene muscles and/or removal of the cervical rib or first rib. This is an outpatient procedure meaning patients go home the same day, usually just an hour or two after surgery.
The outcomes of surgical treatment for thoracic outlet syndrome are good, with up to 80 percent of patients experiencing improvement in symptoms.