Erbs Palsy

Erb's palsy is the most common nerve injury to infants. It occurs at the time of birth when the doctor pulls too much on the fetal neck, stretching and damaging the nerves of the brachial plexus. This is why it is also called brachial plexus palsy. The end result is weakness or paralysis of the baby's arm on the side the neck and shoulders were pulled on too much. The cause of the disease is shoulder dystocia or having the shoulder stuck at the outlet of the birth canal. The fetal head is born but the shoulders are stuck in the birth canal. Pulling on the neck results in the pulling of the nerves in the baby's armpit area, resulting in Erb's palsy.

There are several different forms of Erb's palsy and it all depends on the location of the problem in the nerve plexus called the brachial plexus. Nerves that affect only the lower arm or the upper arm can be separately affected and there is a condition known as Klumpke paralysis, which involves damage to the nerves affecting the baby's hand. There can be drooping of the eyelid on the opposite side of the injury to the arm.

Symptoms are usually seen immediately after the birth of the child. The usual Moro reflex is diminished on one side of the body in the arm and the arm is held flexed at the elbow, tightly against the body. The grasp is minimal at the time of the birth of the baby and spontaneous movement is lacking on the affected side of the body at the level of the upper arm, the lower arm or the hand.

The cause of Erb's palsy or brachial plexus injuries is difficulty in delivery of the baby. The head can be of a normal size and may deliver relatively easily. It's when the shoulders are supposed to be delivered that the problem occurs. The natural response of the doctor is to pull on the head in different directions to get the shoulders out. Too much pulling yields damage to the brachial plexus. It can happen in a breech delivery when the body is out but the shoulders get stuck. The doctor in this case pulls too much on the upper arm to deliver the head. This stretches the brachial plexus and damages the nerves. Breech deliveries are one risk factor for Erb's palsy. Another risk factor is shoulder dystocia, which means "stuck shoulders". The practice of cesarean section for large or breech infants has made for a much less risk of Erb's palsy in most deliveries. Instrumentation can cause brachial plexus palsy and these fortunately are not used as much today as they used to be used.

You can diagnose Erb's palsy and other types of nerve injuries to the brachial plexus by carefully examining the infant's arm, including the Moro reflex examination. If there is pseudoparalysis or weakness of the arm but not paralysis, you will still see a Moro's reflex. Pseudoparalysis of the arm is actually a fracture of the clavicle or arm that makes movement painful so the infant doesn't use the arm very much. If there is Erb's palsy, you will see a floppy arm on the affected side.

The treatment of Erb's palsy involves gently massaging the affected extremity and doing mild range of motion exercises in order to help the nerves come back to life. It takes about three to six months to see a resolution of Erb's palsy using this method but if it does not occur, the surgeon must do surgery to reconnect the nerves in the armpit. Tendon transfer can be done to help the arm work better if nerve surgery fails. Most infants fortunately recover by the age of six months but if there is not recovery after six months or after surgery, the infant is likely to have some residual paralysis of the affected arm for the rest of their lives.

Doctors can prevent Erb's palsy by predicting which infants will be too large to pass through the birth canal and do a caesarean section on those infants. X-rays or ultrasound can do the prediction of the size of the baby.