Thoracic Outlet Syndrome (TOS) causes pain, weakness or numb sensations in the neck, arm and hand. Symptoms and signs of thoracic outlet syndrome are due to the compression or irritation of the neurovascular bundle at the various levels of the cervico-axillary and thoraco-brachial passages.
Depending on the exact site of injury and the injury component of the neurovascular bundle, three distinct syndromes or a combination thereof may be encountered (neurological, arterial and venous).
There are at least six causes of TOS. Although these six are the most frequently cited causes, the first two are the most commonly encountered.
(1) muscle spasm secondary to cervical spine abnormality
(2) cervical ribs (normally there are only thoracic ribs)
(3) anomalous muscle insertion or origin
(4) congenital fibrous bands
(5) tumor
(6) vascular abnormality such as a subclavian artery
aneurysm
Symptoms of TOS include:
· Numbness and tingling of the entire upper extremity or
hand.
· Paresthesias (tingling) of the arm and hand (more
common in the little, ring, and middle fingers).
· Nocturnal (night time) symptoms of pain and
paresthesias.
· Pain in the supraclavicular area (above the collar bone),
shoulder, neck and occasionally headaches.
· If vascular abnormality is present, there may be
cyanosis with activity of the upper extremity if arterial in
origin. Swelling of the extremity occurs if venous in
origin.
The hallmark of this diagnosis is reproduction of symptoms with use of the limb in an elevated position such as combing the hair. There is an exacerbation of symptoms with the arm in a forward reaching position such as when carrying things or driving.
Physical examination will find tenderness and swelling at the muscles above the collarbone and the side of the neck. Sensibility is usually normal. Muscle weakness or atrophy is unusual.
Provocative tests include:
· Wright maneuver: reproduction of symptoms with abduction and external rotation of the shoulder.
· Adson's maneuver: reproduction of symptoms, or obliteration of radial pulse with extension of the
arm while the head is rotated to the other side and the patient holds their breath to full inhalation.
A number of tests can help in the diagnosis of TOS:
· Lordotic chest x-ray: to evaluate the apices of the lungs where tumors can arise that can cause
symptoms of thoracic outlet syndrome.
· Cervical spine series: to evaluate the cervical spine and to assess if there are any cervical ribs
present.
· MRI: to assess the cervical spine nerve roots for possible points of compression.
· CT scan: if there is a history of trauma, to evaluate the first thoracic rib for possible fractures.
· Electrodiagnostic tests: helpful in looking at other causes in the differential diagnosis.
· Thermography: to evaluate cutaneous blood flow or sympathetic response.
The vast majority of TOS cases can be successfully treated with non-surgical specialty care. Examples include:
· physical therapy
· myofascial and postural techniques
· vasomotor-effective medications and blocks
· disease management techniques that reduce the total number of factors impeding recovery
