The brachial plexus is a network of nerves in the neck and shoulder. These nerves carry signals that tell the arm and hand to move. If the brachial plexus is injured, palsy (paralysis) of the arm on that side may result. Although the brachial plexus can be injured at any time, injury is most common during childbirth and usually happens on one side, although it can be on both sides. This condition is not painful and is usually very treatable. Your child can regain full use of the arm. If your child is diagnosed with a brachial plexus palsy, he or she may be referred to a pediatric orthopedist (healthcare provider specializing in treating bone and joint problems in children) or a pediatric neurosurgeon (healthcare provider specializing in treating injuries to the nerves coming from the spine) for evaluation and treatment. Brachial plexus palsy is also called Erb’s or Klumpke’s palsy.
During childbirth, the shoulders may be pulled downward as the baby squeezes through the birth canal. When this happens, the brachial plexus nerves may stretch and be damaged. In some cases, the nerves may even tear. Larger birthweight babies are at a higher risk of brachial plexus palsy because it is harder for them to pass through the birth canal.
The signs of this problem may be noticed at birth or soon after. The problem may be suspected if the infant:
Doesn’t move one arm and the arm hangs limp.
Shows lack of muscle control in the arm, hand, or wrist.
Doesn’t seem to have feeling or sensation in one arm or hand.
Has a droopy eyelid on one side (rare).
The problem is often diagnosed if the doctor notices the signs listed above. Imaging tests may be done to rule out other problems with the baby’s joints and muscles. Nerve tests, such as an electromyography (EMG) or nerve conduction study, may be done to check for nerve signals in the upper arm muscle.
Most children with this problem get better on their own once the nerves heal.
To keep the arm muscles from stiffening, therapy (with an occupational therapist or a physical therapist) may be recommended. During this therapy, the child’s arm is moved through a range of motion. Parents are also shown how to exercise the child’s arm. Parents then do these exercises at home with the infant 2 to 3 times a day.
The child’s condition is monitored regularly for the first 3 to 6 months of the child’s life.
Some healthcare providers recommend botulinum toxin injections to treat deformities and muscle imbalance associated with brachial plexus injury.
In rare cases, when the child doesn’t get better within 6 months or nerve studies indicate that the damage is quite significant, surgery can be done to attempt to restore arm function. Your child’s healthcare provider can tell you more about the surgery if it is needed.
Most children regain close to full movement and flexibility of their arm once the brachial plexus nerves heal. After healing, the arm on the side of the injury may be slightly smaller than the other arm. This size difference won’t get worse, and may improve as the child grows.