Brachial Plexus Injury

摘要

Injury to the brachial plexus during birth has been documented in the medical literature for more than 200 years. Although the ability to predict brachial plexus injury antenatally remains elusive, knowledge of its epidemiology, risk factors, variations in presentation, prognosis, and management can guide therapeutic decisions and potentially avoid lifelong disability. Intrapartum trauma to the brachial plexus encompasses a spectrum of injuries involving the lower cervical and upper thoracic nerves (C5 through T1), which supply the plexus. These five spinal nerve roots combine to form the upper (C5 through C6), middle (C7), and lower (C8 through T1) trunks of the plexus, and the peripheral nerves originating from the plexus innervate the muscle groups of the shoulder, upper arm, forearm, wrist, and hand. The phrenic nerve, comprised of fibers from C3 through C5, and the sympathetic fibers of T1 are affected commonly in brachial plexus injuries, resulting, respectively, in ipsilateral diaphragmatic paralysis and Horner syndrome (miosis, partial ptosis, slight enophthalmos and anhidrosis of the affected side).