Erb’s Palsy (also known as Brachial Plexus and Shoulder Distocia) is a condition that results from nerve injury to the upper plexus involving the nerves that control muscles in the shoulder, arms, or hand.
What is Erb’s Palsy?
Erb’s Palsy is a type of Brachial Plexus injury. The Brachial Plexus is a network of nerves that run from the spine through the shoulder and to the tips of the fingers (shown in the right figure, the labeled nerves are part of the system). Brachial means arm, and Plexus refers to a network of nerves. The Brachial Plexus conducts signals from the spine to the arm and hand. These signals cause the arm and hand muscles to move. In the picture on the right, the Brachial plexus nerves are shown.
Understanding Erb’s Palsy
Erb’s Palsy (a Brachial Plexus injury) is a nerve injury. The nerves that are damaged control muscles in the shoulder, arm, or hand. Any or all of these muscles may be paralyzed. Your child’s disability depends on which nerves are injured and how severely they have been damaged.
Children with Erb’s Palsy are affected in different ways. Here are some examples:
- Some children have no muscle control and no feeling in the arm or hand.
- Some children can move their arms, but have little control over the wrist and hand
- Other children can use their hands well but cannot use the shoulder or elbow muscles.
Erb’s Palsy symptoms range from mild neuropraxia with early recovery to complete disruption with no potential for recovery.
What Causes Erb’s Palsy?
Although Erb’s Palsy (a Brachial Plexus injury) can occur at any time, most cases happen during birth. During the strain of childbirth, the shoulder of the baby could get caught and stretched behind the Pubic Symphysis bone (part of the Pelvis bone). Once the shoulder is caught, the Brachial Plexus can be compressed, stretched or torn as shown in red in the picture to the right.
Many babies with Erb’s Palsy are larger than average at birth. However, newborns of all sizes, including premature babies, can have these injuries. A larger baby will have a greater chance of getting caught behind the Pubic Symphysis bone and getting injured severely.
About 1 or 2 babies in 1,000 suffer from Erb’s Palsy. The symptoms of Erb’s Palsy include a limp or paralyzed arm and/or lack of muscle control in the arm or hand.
There are 4 types of Erb’s Palsy:
- Stretch injuries vary depending on the amount of stretching. The nerves will often be compressed from swelling and bruising from the shoulder being caught. Stretch injuries are the least severe and will usually recover within 1 to 2 years with nearly complete function.
- Neuroma injuries involve scar tissue compressing the nerves and may require surgery to restore function.
- Rupture injuries involve the nerve being torn at several locations and require surgery and therapy to restore normal function.
- Avulsion injuries are when the nerves are pulled from the spinal cord. This is the most severe type of Brachial Plexus injury and requires extensive surgery including a possible muscle transfer to restore function. `
Often the diagnosis is more complicated than one of the four groups above. Because different injury types may cause the same symptoms, it is difficult to know what kind of injury has occured. In addition, sometimes many nerves in the Brachial Plexus may be injured and the nerves may have different types of injuries.
Most cases of Erb’s Palsy are mild and most children will recover in 3 to 4 months. The more severe injuries may take 18 to 24 months to recover. During this recovery time physical therapy may be necessary. Gentle range of motion exercises and electrical stimulation of muscles need to be performed regularly to keep the joints of the arm supple and prevent atrophy. Other treatments that may be necessary are occupational therapy and, in some cases, surgery.