Neurosurgery of the peripheral nervous system: entrapment syndromes of the brachial plexus

Entrapment of the brachial plexus (BP) can be primary or secondary to either trauma or surgery. Most frequently, the BP is entrapped at the “thoracic outlet” resulting in thoracic outlet syndrome (TOS). Hyperabduction syndrome, scalenus anterior (or anticus) syndrome, costoclavicular syndrome, cervical rib syndrome, and long-C7 transverse process syndrome are all entrapment syndromes of the BP. These last terms are used either independently or as part of TOS, although “true TOS” is due to an alteration of the soft tissues at the thoracic outlet and not to bone causes. In 1956, Peet et al. [4] introduced the term TOS to describe a clinical picture with signs and symptoms due to compression of the BP and subclavian vessels at the thoracic outlet. The etiology and clinical presentation of BP entrapment syndromes, including TOS, are variable; diagnosis may be difficult, and treatment is controversial. Knowledge of the anatomy, clinical presentation, diagnostic tools and therapeutic options is very important for correct diagnosis and therapy.