A<unk>  <unk> , also known as<unk><unk>  lesion, is an injury to the<unk><unk> , the network of nerves that conducts signals from the spinal cord to the shoulder, arm and hand. These nerves originate in the fifth, sixth, seventh and eighth cervical (C5–C8), and first thoracic (T1) spinal nerves, and innervate the muscles and skin of the chest, shoulder, arm and hand.<unk> es can occur as a result of shoulder trauma, tumours, or inflammation, or obstetric. Obstetric injuries may occur from mechanical injury involving shoulder dystocia during difficult childbirth, with a prevalence of 1 in 1000 births. "The<unk><unk>  may be injured by falls from a height on to the side of the head and shoulder, whereby the nerves of the<unk>  are violently stretched. The<unk><unk>  may also be injured by direct violence or gunshot wounds, by violent traction on the arm, or by efforts at reducing a dislocation of the shoulder joint". The rare Parsonage–Turner syndrome causes<unk><unk>  inflammation without obvious injury, but with nevertheless disabling symptoms.
Brachial plexus injury
Posterior cord syndrome
Diastematomyelia
Spinal cord injury
Central cord syndrome
Syringomyelia
Accessory nerve disorder
Cernunnos deficiency