Erb’s palsy, a form of obstetric brachial plexus disorder, is an injury that occurs when the nerves in a baby’s upper arm are damaged. It typically affects one or two of every 1,000 babies. The injury usually occurs as a result of a lesion at Erb’s point, the area near the baby’s neck where the fifth and sixth cranial nerves merge to create the upper point of the brachial plexus.
The nerves in the brachial plexus give movement and feeling to the baby’s arm, hand, and fingers. Erb’s palsy is frequently caused by shoulder dystocia during a difficult birth. Infants with this condition usually can’t move the affected shoulder or upper arm, but they may be able to wiggle their fingers.
Sometimes the injury can affect the whole trunk, and usually it affects the spinal cord’s ability to send messages to the arm, wrist, hand, or fingers through normal nerve impulses. Babies with Erb’s palsy often look as if their arm in the affected area is paralyzed.
Erb’s palsy refers only to brachial plexus damage to the upper nerves. If nerves on both the upper and lower ends of the brachial plexus are stretched and injured, the result can lead to a more severe condition known as total or global brachial plexus palsy.