Q. What is the brachial plexus?
A. The brachial plexus is a term used to describe a person’s nerves as they exit the spine in the neck region and progress toward the arm. A complex interweaving occurs in this area as the small individual nerve roots intermingle, reorganize and ultimately become the large nerves proceeding down the arm.
Q. What is brachial plexus palsy?
A. Brachial plexus palsy may be suspected by an obstetrician or pediatrician in a newborn infant if both arms do not have similar strength. This is most often seen as one arm or hand being limp while the child is moving the other about. The cause of brachial plexus palsy is thought to be related to a stretching event that occurred around the time of birth. Most frequently this condition is seen in children who were born vaginally, were large and had a difficult delivery. There have been reports of brachial plexus palsy occurring in children delivered by Cesarean section, although this is rare. The exact cause being different in each case.
Q. Is a limp arm always the result of a brachial plexus injury?
A. No. The most common cause of a limp arm in a newborn is a fracture of the clavicle, or collarbone. These tend to heal remarkably quickly by simply pinning the baby’s sleeve to their shirt as a sling. Almost always the child begins using their arm normally as the discomfort from the fracture fades with healing. Another common cause of a limp arm at birth is a fracture of the upper arm, the humerus. This also is treated with splinting for comfort, and tends to heal quickly.
Q. How often does brachial plexus palsy occur with births?
A. The incidence of brachial plexus palsy is about 0.5-1.5 for every 1,000 babies born.
Q. What tests should be performed for diagnosis and planning for patients with brachial plexus palsy?
A. The most important test is a careful physical examination. This information, compared with prior or future examinations, is the most important piece of information. Magnetic resonance imaging (MRI) studies of the neck area can be performed but should be reserved for preoperative planning if specific questions exist prior to undertaking possible nerve surgery. Similarly, electromyography (EMG) can be helpful at times, but can also be misleading. Physical examination remains the most critical of all the tests.
Q. What can be done to improve the healing process?
A. The majority of brachial plexus palsy cases heal spontaneously, with no intervention at all. At first, simply resting the arm for comfort is the best thing; the healing process may take anywhere from weeks to months or more. Early referral to therapy is beneficial to prevent tightness from developing, but will not speed up the recovery. Patients who are slow to heal may benefit from surgical interventions. Several time points during development have recently been shown to be important to keep track of, as different paths of treatment may need to be pursued:
- For cases in which the child has developed good strength to bend the elbow in the first two months of life, a full or very near full recovery should be anticipated over the next several years.
- If the child reaches 5-6 months of age and still has significant weakness in bending the elbow, microsurgical exploration/repair of the nerves is warranted. Children with good strength at the elbow by this age have not been shown to benefit from this early surgery, compared to therapy and observation alone.
- Regardless of the path chosen, infants with significant elbow weakness at 6 months of age are anticipated to have some permanent limitations in strength and motion of that arm.
Q. Some doctors recommend operating on my child’s nerves by three months of age to guarantee the best recovery possible; why shouldn’t I do this?
A. Peer-reviewed, published quality research studies have shown that, at 5-6 months of age, the nerve surgery should be considered. There are many children who are still very weak at age 3 months is made, but who are much stronger at 5-6 months of age and don’t need the surgery. Those children would have had unnecessary surgery to achieve the same result by a year or two of age. There are ongoing investigations to attempt to refine these recommendations to be as accurate as possible.
Q. If my child can bend her elbow well at 6 months of age, am I assured 100 percent recovery?
A. Unfortunately, no. Many children who have excellent function of their hands and good function of their elbows still develop significant problems with their shoulders. The most common pattern seen is an inability to turn the arm away from the chest (external rotation) and to elevate the arm above the shoulder (flexion). These limitations, or contactures, will result in early and permanent deformity in the shoulder region if left untreated.
Q. What treatment is appropriate for the shoulder problem?
A. Because the infant cannot move the arm normally, the shoulder may become tight when moving in certain directions. Early therapy and a parent home program with gentle daily stretching will minimize this tightness.
If tightness is significant, the physician may recommend surgery to loosen the structures which are restricting motion of the shoulder, releasing the subscapularis muscle and the shoulder capsule. The physician will determine the best technique and best age to perform this surgery.
In many cases, simply improving motion of the shoulder will not be sufficient. If the child does not have the strength to move his arm though the range of motion available, motion will eventually be lost again. For these patients, a surgery that moves muscles of the shoulder region, which are strong to a new position, replacing a muscle, which is weak, should be considered. Then most common of these surgeries is to transfer the Latissimus dorsi and Teres major muscles from the front of the shoulder to the back to improve external rotation. This surgery is often combined with that to relax the contracted front musculature and capsule.
Following these surgeries, the patient is placed into a special cast to hold the arm in an externally rotated position. Further therapy begins as the cast is removed in stages.
Another shoulder procedure which may be appropriate is called a humeral osteotomy. The goal of this surgery is to redirect the upper arm, resulting in the forearm aiming forward, not tightly across the chest. The patient who may benefit from this surgery is usually an older child or one in which deformity of the shoulder joint has already occurred.
Q. What about the elbow and hand problems?
A. Occasionally, deformities occur in which the elbow does not straighten completely and the hand is turned upward (supinated). These can be partially corrected with surgery to redirect an elbow tendon. The correction is never to achieve normal function, rather to maximize functional abilities of the affected extremity.
Hand deficits are extremely difficult to improve in the patients with brachial plexus palsy, since often there are very few muscles which are working at that level. Treatment is always recommended on a case-by-case basis, due to the unique nature of each problem.