Erb's Palsy

Also known as brachial palsy or brachial plexus palsy or Erb-Duchenne paralysis

Erb's palsy is a birth trauma caused by the damage to the collection of nerves called the brachial plexus, located in the underarm and shoulder of the infant. It is caused by the abnormal pulling on the brachial plexus in the birth process. It occurs when there is shoulder dystocia or a misfit between the shoulders and the women's pelvis.

A difficult delivery with a large infant and a small pelvis is the main cause of Erb's palsy. The head fits through the pelvis but the shoulders do not fit through and the infant becomes stuck. If the doctor or midwife pulls too hard on the head and shoulders of the infant, it can stretch or tear the nerves in the shoulder or underarm area of the infant, resulting in nerve damage and Erb's palsy. It usually occurs on just one side of the body but can, in rare circumstances, where the doctor pulls on both sides of the shoulders, it can occur on both sides of the body. It can also be caused by pressure placed on the upraised arms of an infant born in the breech position.

Erb's palsy or brachial plexus palsy can occur in different forms. It can affect only the upper arm of the infant in which the infant can't raise or rotate at the upper arm. It can also affect the upper arm and the rotation of the lower arm. In a variant of Erb's palsy, called Klumpke paralysis, the hand is affected. There is also an eyelid droop on the opposite side of the body in Klumpke paralysis in some cases.

Risk factors for brachial plexus palsy or Erb's palsy include having a large infant greater than 9 pounds or so, having a breech delivery in which the shoulders get stuck in the birth canal. It can also occur if there is shoulder dystocia, in which the shoulders do not fit in the birth canal after the head has gone through.

The symptoms of Erb's palsy are often found soon after birth, often within the first few hours after birth. They involve the absence of a Moro reflex on the side of the body affected with Erb's palsy, an arm that is held against the side of the body and flexed at the elbow. There is a decrease in the hand grip on the side of the body affected by Erb's palsy and a loss of spontaneous movement on the lower arm, upper arm or hand of the affected side of the body.

Doctors can test for the presence of Erb's palsy by revealing a lack of a Moro reflex on the affected side of the body. The infant may have paralysis or extreme weakness noted on the arm of the affected side of the body. Doctors need to rule out the presence of a pseudoparalysis of the arm, which is when the infant has a clavicular fracture or collar bone fracture that impairs mobility of the upper arm due to pain in the fracture site.

The treatment of Erb's palsy may simply be watchful waiting. Erb's palsy can spontaneously get better if the nerves are allowed to rest and heal. Doctors simply pin the arm to the side of the baby's body and allow the nerves to heal and regenerate. If the nerves are torn, watchful waiting may not be enough and the infant will still have problems by six months of age. Surgery on the nerves might restore the function of the nerve and tendon transfer surgery may be required to allow different tendons to make the arm work than normally used. Some practitioners recommend gentle massage and exercises directed at increasing the range of motion of the arm while the nerves are healing. This can be done with or without surgery to the affected arm.

Most infants resolve their brachial plexus palsy within six months of the delivery. If there is not spontaneous return to normal functioning, then the doctor may wish to consider surgery to the affected area.