It is defined as a brachial plexus and their escorting vascular structures compression, during their itinerary through the neck until they leave the thorax.
This pass is narrow because of its anatomical form, but occasionally rib variations may be found, that difficult neurovascular structures path. In addition, space size would change according to arm position or lifting weight.
There are two types of compression, permanent or static and intermittent or dynamic.
There are three troublesome áreas. Above clavicle there are 2 possible compression spaces; interscalenic triangle (with scalene muscles and first rib vertex) and costoclavicular space (between clavicle and first rib). Through this space passes the brachial plexus roots and the subclavian artery. In the infraclavicular portion there is a third space called subcoracoidal.
Patient will refer arm irradiated pain with finger numbness, nuisance, skin color and temperature changes. Occcassionally these symptoms degenerate when raising arms or carring heavy weight.
There are thee clinical kind of compressions, pure neurologic or pure vascular and mixed.
Diagnosis must be done by exclusión, rejecting other pathologies with same symptoms. Surgeon has to be attentive to it and having wide knowledge and experience in this situation, to make good surgical indication and surgical technique.
Differential diagnosis scheme should be:
- First motor neuron injury: amyotrophic lateral sclerosis.
- Intraaxial injury: syringomyelia, poliomyelitis.
- Motor mononeuropaty: carpal tunnel syndrome, ulnar nerve compression in elbow.
Complete check must be done in the presence of clinical suspicion. Not only clinical provocation tests but also image and neurophysiological test to clarify diagnosis can be done.
Physiological and anthropomorphic factors are defined that influence in this syndrome appearance. Classical biotype is a long neck woman asthenic constitution, explaining scapular joint pain irradiating medial arm, with ulnar forearm numbness to hand and posible abductor pollicis brevis muscle athropy on tenar eminence.
What can surgery achieve?
With surgery we can decompress and release the nerve and vascular structures all along their path through the neck and thorax, obliterating the pain, tingling and changes in skin color and temperature.
In case of cervical ribs, unilateral or bilateral, complete or incomplete to varying degrees, in addition to the neurovascular release, the cervical ribs should be disrupted and resected because the presence of these bony structures increases the reflection angle of the primary inferior trunk above the anterior face of the middle scalene muscle and that causes a nerve compression point in this area.
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