A Nerve Injury
Erb’s Palsy can happen when a nerve is stretched unnaturally as the head and the shoulders pass through the birth canal. As it affects the spinal cord’s ability to send messages to the arm, the infant usually can’t move the affected shoulder or arm.
Common Types of Nerve Injury*
Neuropraxia
Compression or stretch injury causes temporary disruption of nerve conduction, yet the complete nerve stays intact. This injury will usually heal on its own.
Axonotmesis
The nerve is damaged but partially remains intact.
Neurotmesis
There is a complete nerve transection, surgical repair is probable.
Ruptures
The nerve is torn, a rupture injury will not heal on its own.
Avulsions
Avulsions are the most severe types of nerve injuries. The nerve has completely torn away from the spinal coder. The affected nerve can’t be reattached to the spinal cord.
Erb’s Palsy Symptoms
Erb’s Palsy can be identified if the baby shows weakness or cannot move the affected arm. there are a number of symptoms that parents can look for after their baby is born:
- The infant struggles to move their arm or has pain when moving
- The infant keeps their arm against their body with a bend at the elbow
- The baby struggles to grip objects with their hand on the affected side
- Impaired circulatory, muscular and nervous development
- Arm numbness
- Partial or full paralysis of the arm
Causes of Erb’s Palsy
Erb’s Palsy often occurs during difficult labour. The brachial plexus nerves are stretched when the baby is passing through the birth canal due to the baby’s head being turned in one direction while their arm is being pulled in the opposite direction. If the baby comes out face-first, the shoulder may be excessively pulled during birth. This is caused when the baby’s arms are pulled backward over their head so he or she can fit through the birth canal. In some cases, the baby’s shoulder may be dislocated, when excessive stretching causes a nerve injury to the brachial plexus.
Even though most Erb’s Palsy injuries occur during birth, it should be noted that Erb’s Palsy can also occur as a result of major trauma such as a physical knock or pressure to the neck during the baby’s first few months of life.