Obstetrical brachial plexus paralysis (OBPP) is an injury to all or a part of the brachial plexus, a network of nerves that provides movement and feeling to the shoulder, arm and hand, which is recognized at the time of delivery. The cause is often due to a stretching or tearing of the baby’s brachial plexus during a difficult delivery when the person delivering the infant must exert more force than usual to extract the baby.
In 1768, the first known description of neonatal brachial plexus palsy was documented by William Smellie. In the late 1800s, Wilhelm Heinrich Erb (Erb’s palsy) depicted cases of upper trunk nerve injuries involving C5-C6 and Augusta Dejerine Klumpke (Klumpke’s palsy) described palsies of the lower brachial plexus where C8 and T1 are involved. The World Health Organization lists the occurrence at 1% to 2% of live births worldwide with higher numbers in underdeveloped countries. In the United States, prevalence is approximately 0.2%.
Jeffrey S. Kanel, MD, an orthopedic surgeon at Pediatric Orthopedic Associates of Silicon Valley in San Jose, Calif., said risk factors of a brachial plexus injury could include anything that would cause a difficult delivery including large birth weight, multiple pregnancies and any type of assistance needed such as vacuum assistance or forceps delivery.
“Interestingly, previous deliveries resulting in brachial plexus palsy are also a risk factor,” said Kanel. “Moreover, even with a Cesarean section, the clinician can still have trouble extracting the child. One would not think this would be the case, but the fact that a woman is having a C-section often means that delivery is difficult.”
Other risk factors include breech presentation at birth, shoulder dystocia and maternal diabetes.
Types of brachial plexus injuries
According to the Cincinnati Children’s Hospital Medical Center’s Web site, too much force on the brachial plexus can cause varying degrees of injury to the nerves. The four types of injuries are:
- Avulsion — the nerve is torn away from its attachment at the spinal cord; the most severe type
- Rupture — the nerve is torn, but not at the spinal cord attachment
- Neuroma — scar tissue has grown around the injury site putting pressure on the injured nerve and preventing the nerve from sending signals to the muscles
- Neuropraxia — the nerve has been stretched and damaged, but not torn.
“Most children have just a neuropraxia and they recover spontaneously,” said Michelle James, MD, a pediatric orthopedic upper extremity surgeon for Shriners Hospital for Children Northern California, Sacramento, Calif. “Usually the children who we see in our brachial plexus clinic have a more severe injury. Often, the four types of brachial plexus will occur in the same child.”
The brachial plexus is made up of at least five different nerve roots originating from C4 to T1 that intersect and form a plexus, explained James. These roots leave the spinal cord at those levels, commingle, and become various peripheral nerves in the upper extremity all the way from the shoulder down to the hand. Some roots may be ruptured, some avulsed and a few could have neuropraxia.
“The injury can be broken down even further into a preganglionic tear versus a postganglionic tear,” said Kanel. “Preganglionic tears have a poor prognosis compared to postganglionic tears.”
The newborn with a brachial plexus injury will often present with a flaccid upper extremity. With Erb palsy, the arm is internally rotated and pronated with no movement at the shoulder or elbow. Hand and wrist flexion are present. With complete brachial plexus paralysis, the entire arm and hand are flaccid with no movement.
“A Horner sign (eye ptosis and myosis) may be noted, which suggests an avulsion directly off the spinal cord,” said Kanel. “A winged scapula implies an injury to the long thoracic nerve which again shows the injury is close to the spinal cord. Both of these are preganglionic tears and have a poor prognosis.”
Even with an upper plexus injury, which is by far the most common, the infant can still have little or no spontaneous movement of the entire upper extremity early on, added Kanel. During the period of the first week or so, the clinician will start to see activity in the hand again.
“Clearly, the hand is not damaged, but the infant shows no motor activity in his or her shoulder yet,” Kanel said.
Recovery and prognosis
Depending on the degree and site of nerve injury, the beginnings of recovery may be noted within a few days. Most clinicians agree that spontaneous recovery of biceps function is the key to healing of this injury. A certain degree of recovery by 3 to 6 months generally indicates that the infant will recover better on their own than with brachial plexus surgical exploration and grafting. Nerves regrow from the neck down the arm and the rate of growth is 1 mm per day or 1 inch per month. An incomplete recovery may occur if the nerves do not fully reattach at their original motor and sensory targets. Depending on the injury, some patients will continue to experience weak muscles, decreased sensation or incomplete range of motion into adulthood. For avulsion and rupture injuries, prognosis is poor unless nerve surgery is performed. And even then, full recovery is not possible. Generally, patients with neuropraxia either recover partially or completely.
Range of motion, contracture prevention
It is crucial that the parents perform passive range of motion exercises on their baby every day to prevent contractures and keep the joints flexible.
“We have a brachial plexus multidisciplinary specialty clinic here and we follow the babies closely to monitor their recovery and to counsel the parents about range of motion exercises,” said James. “The functional impairment from this condition is most commonly seen in the shoulder with a difficulty reaching the face, head and overhead,” she said. “Since it is mostly the shoulder, the child is still able to use his or her hand in front of the body but has trouble positioning the hand in space around the head.”
James uses a method of examining the infants that allows her to tell which muscles are working and how strong they are. If they are not getting a certain amount of recovery by the 3- to 6-month window, nerve exploration and grafting may be recommended.
“These are not curative procedures, but rather a way of jump starting the healing process if the baby is not healing properly,” she said.
If the infant does not need surgery, he or she will be monitored for the development of joint contractures or problems performing activities. She has used different types of orthoses and splints throughout the years. As the children get older, they often develop flexion contractures.
“We will use custom crafted orthoses to help hold the elbows straight,” James said. “The intention is to prevent the elbow contractures from becoming worse and interfering with their function.”
James also uses a shoulder abduction orthosis following shoulder reconstruction surgery.
Surgery options include:
- Neurolysis — removal of the constrictive scar tissue surrounding the nerve
- Neuroma excision — the neuroma is removed and the nerve is reattached either with end-to-end techniques or nerve grafts
- Nerve grafting — when the gap between the nerve ends is so large that it is not possible to have tension-free repair using the end-to-end technique, nerve grafting is used
- Neurotization — usually used when there is an avulsion. Donor nerves are used for the repair.
Additional surgery as the child grows may be considered to improve the overall functioning of the limb. They include:
- Arthroscopic surgery
- Shoulder reconstruction
- Joint fusion
- Muscle and tendon transfers (to rebalance arm)
- Rotational, wedge or sliding osteotomies
- Elbow reconstruction
“Nerve grafting is much more enthusiastically embraced in Europe than the United States, but nevertheless, there are a number of centers in the United States that have active nerve grafting programs,” said Kanel. “The results have varying success. Even with successful nerve grafting, the baby can be left with some dysfunction, the most common being shoulder contracture with lack of external rotation or an internal rotation contracture or an adduction contracture and that can be treated in the older child with either a release or tendon transfer to promote external rotation of the shoulder.”
There is a large chance of deformity of the glenohumeral joint, which could cause dislocation of the shoulder.
“One would want to prevent that at all costs,” he said. “If it does happen, it must be reduced immediately. It is a poor prognostic sign if that happens to an infant.”
Tendon transfer for external rotation of the shoulder is probably the most common secondary reconstructive procedure done for this injury, according to Kanel. Less common surgeries include elbow or hand releases or tendon transfers.
“In the hand and wrist for a distal brachial plexus palsy, the results of any soft tissue surgery or secondary reconstruction are quite variable,” he said. “They have to be individualized and performed only in particular circumstances when you are trying to specifically improve the function of a certain muscle.”
Orthotic intervention in brachial plexus patients does not typically commence until 4 to 5 months of age. The orthotist works closely with the physical therapist and occupational therapist to prevent contractures and maintain range of motion and good functional hand position.
“We will often provide lightweight thermoplastic orthoses splinting made from semiflexible materials that are polyethylene based,” said Kaia Busch, CPO, director of orthotics for Hanger Orthopedic Group in Seattle. “There are several types of custom and off-the-shelf orthoses. The goal is to keep the hand in a functional position. Sometimes, we will use an off-the-shelf device such as a Comfy SplintTM. They are easily modified with a soft covering so children can put it near their faces without injuring themselves.
If there is still weakness present as the child gets older, Busch will continue to use various devices to position the elbow, wrist and hand.
“We also pay close attention to the shoulder to ensure there are no dislocation or subluxation issues,” she said.
It is important that the therapy modalities coincide with the orthotic interventions and that the parents continue to work with the child every day to ensure good functional outcomes, said Busch.
Communication with the parents and getting them involved in their baby’s recovery is vital.
“When dealing with the parents of a newborn, obviously one does not know what the recovery is going to be,” said Kanel.
So he will talk to them about looking for return of bicep function, working on range of motion and watching what happens in the following 6 months. Kanel looks for return of bicep function by 5 months old. He tells the parents that if there is some return, he is content to follow the child and continue to work on range of motion. In the slightly older infant, like 9 months old, he will have the parents help the baby work with hand grasping activities.
“Early on I tell the parents to expect this extremity to be the nondominant extremity,” said Kanel. “I tell them that our goal is to maximize function and to make this the best helping hand they can make it. In the majority of patients with C5-C6 lesions, spontaneous complete or near complete recovery will occur.”
For more information:
- Brachial plexus injury. Cincinnati Children’s Hospital Medical Center. Available at www.cincinnatichildrens.org/health/info/neurology/diagnose/brachial-plexus.htm. Accessed April 19, 2006.
- Anatomy of the brachial plexus in infant – medical illustration. Available at www.doereport.com/generateexhibit.php?ID=1398. Accessed April 19, 2006.
- Brachial plexus injuries, obstetrical. Available at: www.emedicine.com/orthoped/topic466.htm. Accessed April 19, 2006.
- Neonatal brachial plexus palsies. Available at www.emedicine.com/pmr/topic215.htm. Accessed April 19, 2006.
Rachel Kelley is a staff writer for O&P Business News.