THORACIC OUTLET SYNDROME
( T O S )
Thoracic outlet syndrome (TOS) is a condition whereby symptoms are produced (such as numbness in fingers, pain in shoulder, arm, and neck) due to compression of nerves and/or blood vessels in the upper chest. The passageway for these nerves and blood vessels to exit the chest and supply the upper extremities is referred to as the thoracic outlet.
Muscle, bone, and other tissues border the thoracic outlet. Any condition that results in enlargement or movement of these tissues of or near the thoracic outlet can cause the thoracic outlet syndrome. These conditions include muscle enlargement (such as from weight lifting), injuries, an extra rib extending from the neck (cervical rib), weight gain, and rare tumors at the top of the lung. Often no specific cause is detectable.
Risk factors include occupations that involve heavy usage of the upper extremities against resistance, including jack-hammer operators and dental hygienists, weight lifting, pregnancy, and obesity. Any condition that causes encroachment of the space for the brachial plexus at the thoracic outlet can lead to thoracic outlet syndrome, including poor posture.
Symptoms include neck, shoulder, and arm pain, numbness in the fingers, or impaired circulation and flushed sensations to the extremities (causing discoloration). The involved upper extremity can feel weak. Often symptoms are reproduced or worsened when the arm is positioned above the shoulder or extended. Patients can have a wide spectrum of symptoms from mild and intermittent to severe and constant. Pains can extend to the fingers and hands, causing weakness.
The diagnosis of thoracic outlet syndrome is suggested by the symptoms and supported by findings of the doctor during the examination.
Certain maneuvers of the arm and neck can produce symptoms and blood vessel "pinching," causing a loss of pulse. This includes the Adson's maneuver, whereby the examiner moves the shoulder joint into positions that can cause pinching of both the nerves and artery to the tested arm.
Differential Diagnosis :
■ Extra cervical rib or ligamentous (false) rib.
■ Pancoast tumor.
■ Brachial plexopathy – infective or traumatic.
■ Heart attack (le side).
■ Vertebral artery disease or aneurism.
■ Hyperkyphosis or scoliosis of the thoracic spine.
■ Neck degenerative changes, cervical bars and osteophytes.
■ Radial Neuropathy.
■ Complex Regional Pain Syndrome 1(CRPS1) - RSD.
■ Problems (age related) with the neck including discs and spinal joints.
■ Ankylosing spondylitis.
■ Median neuropathy.
■ Ulnar neuropathy.