The brachial plexus (BRAY key el PLEK sis) is a group of nerves that starts in the spinal cord at the neck and controls the hand, wrist, elbow and shoulder. The nerves signal these parts of the body to move and to feel (Picture 1).
What Causes Brachial Plexus Injury
In most cases an injury happens to the baby during birth. It can happen for several reasons.
The main cause is the birth of a large baby through a small birth passage (Picture 2). It can also happen if the mother has high blood sugar. Mothers with high blood sugar levels are more likely to have big babies.
If labor lasts longer than 24 hours, the doctor might have to use forceps, a suction device or other tools or surgeries to help the birth. Also, if the baby has trouble breathing or is in a hard birth position, the doctor may have to use tools to help the birth. The use of these tools may play a part in the injury.
A brachial plexus injury can happen if the baby’s shoulder is stretched during birth (shoulder dystocia—dis-TO-se-ah) or if he has a fracture, twisted neck muscles or shoulder dislocation.
An injury to the brachial plexus causes problems with the messages the nerves send to the shoulder, arm or hand on that side of the body.
Car accidents, sports injuries or falls may cause brachial plexus injuries in an older child.
Your child may have all or only some of the following symptoms on the side of the injury:
- Limited or no movement
- Muscle weakness or limpness
- Less movement in a joint such as where the shoulder joins the body on the affected side
- Less perspiration (sweating)
- Loss of feeling
- Drooping eyelid
- Constricted (smaller) pupil in the eye
- Contractures (shortening or drawn together) of the muscles at the joints
Types of Nerve Damage
There are several levels of nerve damage.
- Stretch (neurapraxia, ner-ra-PRAK-see-ah): The most common and mildest form of nerve injury. The nerve has been stretched and damaged but not torn. It generally heals on its own in four to six weeks. Children with this type of injury usually recover fully from the injury (Picture 3).
- Tear (rupture): The nerve is torn, but not where it attaches to the spinal cord. Children usually require surgery (Picture 4).
- Scar (Neuroma, ner O ma): A scar may form in a stretch or tear type of injury. Some healing of the nerve may happen without surgery (Picture 5). If healing does not happen, surgery may be required.
- Avulsion (ah-VUL-shun): The nerve root is cut from the spinal cord. Avulsion is the most serious nerve injury and early surgical treatment is necessary.
Positioning Your Infant
- Be careful when moving your child’s affected arm but do not be afraid to gently move it.
- Pick up your child by supporting him under his hips, behind his shoulder blades and under his head.
- When dressing him place his affected arm into clothing first to avoid over-stretching the nerve.
- For sleeping, place your baby on his back and place a rolled towel or small blanket under his unaffected side. He will then be partly lying on his affected side.
- Hold him on different sides during feedings and throughout the day so he turns his head to look at you.
- Position your child so he will turn his head toward his affected arm. Place toys and mirrors on your child’s affected side so he turns his head to look at them.
- Place him on his tummy a few minutes every day to help him get stronger. (See Tummy Time, HH-II-173)
These activities will encourage him to turn his head which prevents tight neck muscles or head flattening.
Treatment of Brachial Plexus Injury
We closely watch your child’s injury through his first nine months of life. If he has a nerve avulsion (see above), he will need surgery in the first few months. After surgery, your child will be better able to move his arm and have increased feeling in his arm and hand. Sometimes other treatments are needed to help your child get and keep full use of his arm. Those may include splints, casts or Botox injections.
If he has one of the milder forms of nerve damage, you will be taught a series of exercises to do with your baby at home. The exercises help him learn to move his arm. He will be seen at ages three, six and nine months to see if he gets better without surgery. At each visit, we will see how your child is doing. We will watch for specific improvements in your child’s arm movement at each appointment. If the use of his arm does not get better with the exercises, your child will need surgery. It will be done between the ages of six and nine months (see ROM exercises, HH-II-186).
Infants may also have mild symptoms which get better in the first month of life. They do not require surgery and completely recover in the first two years of life.
Your child’s treatment plan includes home exercises and regular follow up with the doctor. This is crucial for your child’s full recovery.
If there are any problems or if you have any questions, be sure to call the clinic at (614) 722-6299.
HH I-334 9/13 Copyright 2011, Nationwide Children's Hospital