216: BRACHIAL PLEXUS INJURY

Course of the brachial plexus and subclavian artery between the anterior scalene and middle scalene muscles. Dilatation of the subclavian artery just distal to the anterior scalene muscle is illustrated. Immediately distal to the anterior and middle scalene muscles is another potential area of constriction, between the clavicle and the first rib. With extension of the neck and turning of the chin to the affected side (Adson maneuver), the tension on the anterior scalene muscle is increased and the subclavian artery compressed, resulting in a supraclavicular bruit and obliteration of the radial pulse. (From Ropper AH, Samuels MA. Adams & Victor’s Principles of Neurology. 9th ed. New York, NY: McGraw-Hill; 2009.)

Brachial plexus. The numbers in parentheses refer to the segmental origin of the nerves depicted. (Reproduced from Waxman SG. Clinical Neuroanatomy. 26th ed. New York, NY: McGraw-Hill; 2010.)

Brachial plexopathy. Axial (A), sagittal (B), and coronal (C, D) short tau inversion recovery (STIR) MR images demonstrate abnormal enlargement and abnormal high signal involving the right C6, C7, and C8 nerve roots, and the trunks and divisions that originate from these roots (arrows). Diffusion-weighted MR imaging (E) demonstrates abnormal reduced diffusion within the right C6, C7, C8 nerve roots and their corresponding trunks and divisions (arrow). These findings are compatible with radiation-induced brachial plexopathy. (From Longo DL, Fauci A, Kasper D, et al., eds. Harrison’s Principles of Internal Medicine. 18th ed. New York, NY: McGraw-Hill; 2012.)