Thoracic outlet syndrome (TOS) is a disorder in which pain results from the compression of nerves or blood vessels within the thoracic outlet, the space just below the neck, between the collarbone and ribs. This condition commonly develops as a result of traumatic or repetitive injury. Symptoms of thoracic outlet syndrome vary depending on the type and severity of the condition, but frequently present as pain between the muscles of the neck and shoulder or between the first rib and collarbone. In the majority of cases, the condition is neurogenic, not vascular, in origin.
Causes of Thoracic Outlet Syndrome
Thoracic outlet syndrome presents more frequently in women than in men. The onset of symptoms typically occurs in middle age. Causes of TOS include inborn abnormalities, everyday activities, and accidents, any of which may result in nerve or blood vessel compression. These causes include:
- Traumatic injury, especially vehicular accidents
- Congenital anatomical defects
- Tumors or enlarged lymph nodes
- Poor posture for prolonged periods
- Repetitive stress to the area
Repetitive stress to the neck, shoulder, or arm can occur in a variety of situations, including computer or factory work, or sports activities, particularly weight-lifting.
Symptoms of Thoracic Outlet Syndrome
TOS typically causes uncomfortable sensations in the arm, shoulder, or neck, including:
- Burning, tingling, numbness
- Weakness in the arm, or a weak grip
- Swelling or in the arm
- Pale or bluish color of skin
- Abnormal sensitivity to cold
Throbbing pain in the collarbone is usually the result of vascular compression.
Diagnosis of Thoracic Outlet Syndrome
A simple, commonly used test for TOS is the elevated arm stress test in which the patient is asked to raise closed fists over the head for about 3 minutes. If this action provokes the symptoms, it is likely that the patient has TOS.
Other diagnostic tests for TOS include imaging tests, including:
- CT or MRI scans
- Ultrasound scans
In addition, tests may be performed to evaluate blood circulation and nerve conduction.
Treatment of Thoracic Outlet Syndrome
Treatment of TOS depends, to a certain extent, on the cause of the problem. There are three possible approaches to the disorder; the two more conservative treatments are always tried before a surgical procedure is contemplated.
Medications are administered to patients with TOS to relieve pain, to provide muscle relaxation, and, if the condition has a vascular cause, to either dissolve blood clots (thrombolytic medication) or thin the blood (anticoagulants).
Physical or Chiropractic Therapy
Chiropractic therapy can relieve nerve or blood vessel compression through hands-on manipulation. Both chiropractic and physical therapy serve to improve range of motion. Specially designed physical exercises are usually recommended to assist in strengthening the muscles in the region.
In a relatively small percentage of cases, TOS may require surgery. Sometimes, this means a simple procedure known as an angioplasty, in which a catheter with a balloon attached to it is inserted into the vein and inflated to help open the vascular pathway. In other cases, more extensive must be performed in order to alleviate compression. This surgery, known as decompression surgery, usually involves removing the first rib and any abnormal muscle or fibrous tissue.
Almost all patients with thoracic outlet syndrome recover completely, whether they require surgical intervention or not.