Thoracic Outlet Syndrome
Thoracic Outlet Syndrome (TOS) is a condition in which the nerves, blood vessels, or both are compressed in the thoracic outlet. The thoracic outlet is the area between the base of the neck and the armpit. The pain from TOS is felt in the shoulders and the neck and may include numbness in the fingers.
There are three types of TOS: neurogenic, vascular, and nonspecific. In neurogenic TOS, an extra cervical rib may be present at birth or the brachial plexus may be compressed. The brachial plexus is a set of nerves that extend from the spinal cord through part of the neck and into the armpit, controlling movements in the hand, arm, and shoulder. Neurogenic TOS accounts for the majority of cases. Vascular TOS develops when veins or arteries under the collarbone become compressed. Nonspecific TOS occurs when one suffers from chronic pain of the thoracic outlet, but no neurological deficit is found.
Symptoms of neurogenic TOS include loss of muscle in the thumb area; tingling in the arms or fingers; pain in the neck, shoulder or hand; and a weakened grip. Symptoms of vascular TOS include arm pain, swelling of the arm, blood clots in the upper body veins or arteries, discoloration of the hands or fingers, a weakened pulse in the affected arm, numbness in the fingers, cold hands, loss of strength in the arm or neck, and a throbbing sensation near the collarbone. Symptoms of nonspecific TOS include pain in the area of the thoracic outlet that worsens during movement, but a specific cause cannot be determined
Causes of TOS include, but are not limited to, trauma or injury, tumors, excessive weight gain, extra ribs, weight lifting, pregnancy, joint pressure, repetitive activity, and poor posture. Enlargement of the tissue in the thoracic outlet can also cause TOS. Maintaining relaxed tissue in the upper chest can help prevent TOS.
Diagnosis of TOS is difficult, and oftentimes, a consultation with a neurologist is required. A health professional will need to perform a physical examination, review symptoms, and collect a medical history. A doctor may try to reproduce symptoms while checking for a pulse in the affected area. Several tests may also be conducted in order to obtain a proper diagnosis including X-rays, MRI, CT scan, ultrasound, EMG, angiography, and a nerve-conduction study.
Various types of treatment are available to help with the symptoms of TOS including physical therapy, nerve blocking injections, and acupuncture. Anti-inflammatory medications, clot-dissolving medicines, and muscle relaxants have also proven effective. If all other avenues of treatment fail, surgery is sometimes considered. The type of surgery performed depends on the cause of the TOS. Transaxillary surgery, in which a small incision is made in the chest to remove a part of the first rib to relieve compression, can be performed. Supraclavicular surgery, in which a small incision is made under the neck to repair the compressed blood vessels and remove the muscle that is causing the compression, can also be performed. The first rib may also be removed if necessary. Infraclavicular surgery can be done by making a small incision under the collar and treating the compressed vein.