Thoracic Outlet Syndrome (TOS)

What is it?

Thoracic outlet syndrome (TOS) is a painful condition affecting the nerves (known as the brachial plexus) and/or vessels that course from the base of the neck to the shoulder and arm through a narrow passageway known as the thoracic outlet. Symptoms result from compression or narrowing of these neurovascular structures by various structures – such as scar tissue, thickened neck musculature, or an extra rib (known as cervical rib) – that get in the way. This condition is often seen in overhead athletes, individuals with poor posture, body builders, and people who do work involving repetitive overhead activity, though it can occur in virtually anyone.

What symptoms does it cause?

Patients with TOS typically experience pain in the neck and shoulder often radiating into the arm and hand (usually the last two fingers). The pain can be described as achy or burning in nature, and it is often associated with numbness and tingling. Sometimes there might be swelling of the affected arm with arm elevation. Symptoms are generally worse with activity and with the arms overhead.

How is it diagnosed?

TOS is a difficult thing to diagnose and requires a physician who is experienced with making the diagnosis. Though sophisticated nerve studies often cannot reliably diagnose TOS, they may be used to rule other neurologic problems and can help with making the correct diagnosis. Imaging studies, such as X-ray or MRI, may be used to evaluate the neck, shoulder, and neurovascular structures. In rare cases, if there is concern for a blood clot, special tests can be done to look at the blood vessels.

How is it treated?

Treatment is catered to each individual. Many patients will experience relief of symptoms with a sufficient course of physical therapy. An important part of treatment is avoiding activities that aggravate it. In severe cases, medications may be needed to control the symptoms. When the condition is more severe or abnormal structures are present, surgery may be considered.