Thoracic Outlet Syndrome
Brachial Plexus and Peripheral Nerve Clinic
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 excessive pressure placed on the blood vessels by either muscle in the neck, called the anterior scalene muscles, or bony structures of the thoracic outlet.
Common Symptoms of Thoracic Outlet Syndrome
Patients with thoracic outlet syndrome most often complain of pain that extends down the arm and in the hand (specifically the ring finger and pinky). It also can involve pain in the forearm and upper arm. Typically, this pain is sharp, burning or aching and causes numbness or tingling.
Risk Factors for Thoracic Outlet Syndrome
Thoracic outlet syndrome can affect adults and children of all ages and genders, though it tends to not become prevalent until the teenage years and into adulthood. It also can develop spontaneously during middle age, when it is seen more commonly in women than men because of poor muscular development and posture. It can be common among those who are tall and thin, as with those who have Ehlers-Danlos syndrome.
Thoracic outlet syndrome also may affect those who participate in sports requiring repetitive motions of the arms and shoulders. They include swimmers, volleyball players, baseball players and weight lifters. Sports are not the only activity that may result in this syndrome. The repetitive motions required to play stringed musical instruments and to work in carpentry and construction also can cause thoracic outlet syndrome.
Diagnosing Thoracic Outlet Syndrome
Thoracic outlet syndrome often is diagnosed with a neurological exam during which 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 is located in the neck.
With this kind of exam, doctors sometimes see changes in sensation, motor function and adequate blood flow (decrease in the pulses when arms are elevated above the head).
Imaging and other studies also may 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 that can compress the nerves. Magnetic resonance imaging (MRI) – especially using MR arteriography (MRA) or MR venography (MRV) – also can be useful because it can show variation in the blood vessels or nerves. This is evidence of compression, particularly when the imaging is obtained in the positions that cause the symptoms (for example, arms raised above the head).
Treatment of thoracic outlet syndrome most often involves physical and occupational therapy, along with medicines for symptomatic pain relief. However, in the 10–20% of cases that don’t improve with those treatments, thoracic outlet surgery can be used to increase the space in which the blood vessels and nerves pass 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, or collarbone. This may involve removing scar tissue, detaching parts of the scalene muscles and/or removal of the cervical, or first, rib. This is an outpatient procedure that allows patients to 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% of patients experiencing improvement in symptoms.