Brachial Plexus Palsy: A Perspective on Current Management

Herman A. Hein, M.D.
Professor of Pediatrics
University of Iowa Hospitals and Clinics

First Published: Winter 2000
Last Revised: September 2003
Peer Review Status: Internally Peer Reviewed

Although known to the ancients, brachial plexus palsy (BPP) first attracted significant attention toward the end of the nineteenth century. Duchenne coined the term "obstetric palsy" in 1872 in his book, Traite de L'electrisation Localisee. There he described in detail four cases of proximal root paralysis occurring after delivery.

Unfortunately, the term "obstetric palsy" is still used by some, especially the Europeans, and connotes a cause and effect relationship between the events of delivery and the palsy. As I will discuss below, it is now known that this is not the case in many patients, especially, those with the poorest outcomes.

In the English literature, Erb's name became attached to paralysis of the upper nerve roots through his classic description in 1874. Klumpke's name is associated with lower root paralysis and likely dates to his article in the French literature appearing in 1885.

Anatomy and Pathophysiology

Brachial plexus palsy occurs in 0.1% to 0.4% of live births. The brachial plexus consists of the lower four cervical roots (C5-8) and the first thoracic root (T1) (See Fig. 1). Exiting through the anterior vertebral foramen, then coming through the posterior triangle of the neck, by the clavicle and in the direction of the upper extremity, the brachial plexus may be rather easily injured as a result of traction on the extremity or distraction of the head from the clavicle. Although freely mobile at its origin, more distally the plexus is anchored to stationary tissues around the clavicle. As a result of these points of fixation, the nerves can rather easily be damaged by excessive traction. In addition, trauma, anomalous cervical ribs, and inflammatory processes in this area can all cause severe damage to the brachial plexus. Young adults not uncommonly sustain brachial plexus injuries because of sudden acceleration or deceleration with resultant lateral neck trauma such as seen in victims of motorcycle accidents. Newborns may sustain similar injuries during birth. During the process of birth, forces can be exerted on the neck that put undue stress on the brachial plexus, and the resultant damage can cause BPP.

The type of injury that occurs with stretch damage to the brachial plexus depends on where the injury takes place. Proximal lesions within the spinal canal involve the nerve rootlets and are called avulsions, with the rootlets torn from the spinal cord proximal to the formation of a mixed nerve root. Avulsed nerve rootlets do not recover their function and surgical reconnection of nerve rootlets to the spinal cord does not appear to be possible.

Different types of lesions occur once the nerve rootlets coalesce to form the mixed nerve root that traverses and exits the rootcanal. A complete rupture (neurotmesis) is similar to a laceration and both the neuronal and sheath elements are disrupted. Partial or complete rupture may evolve into a neuroma as the sprouting neurons of the growth bulb of the proximal damaged end form a mass of fibrous tissue and disorganized neurons in their attempt to reach the distal end. Nerve conduction through the neuroma depends on the number of neurons making the correct connection distally.

Axonotmesis is the disruption of the internal neural elements with the sheath elements remaining intact. The proximal nerve growth bulb usually reconnects to the disconnected neural elements inside the neural sheath. Neuropraxic lesions are temporary nerve conduction blocks without permanent structural damage and recovery usually occurs quickly and completely.

Shoulder dystocia is the obstetric factor commonly associated with BPP. Breech presentation and large birth weight are also associated factors. However, Gherman et al, (Am J Obstet Gynecol 1998;178:423-7) recently provided evidence that, taken together with previous reports, suggests that not all Erb's palsy is traction related. Rather, an in utero insult perhaps combined with a susceptibility to pressure or traction may be etiologic. A most important finding of their study was the fact that a significantly higher rate of morbidity was noted among those babies with Erb's palsy without shoulder dystocia. Rather than the expected persistence rate of 1-5%, they noted 41% had permanent injury at one year of life. These authors suggest that many permanent brachial plexus injuries may be due to in utero forces that precede the actual delivery. Thus, before the recognition of the shoulder dystocia, a significant degree of stress or pressure may have already been applied to the brachial plexus. Moreover, even when a brachial plexus injury is associated with shoulder dystocia, it may have occurred independent of traction applied by the obstetrician. Unfortunately, the authors indicate that currently, attempts to predict the babies at risk for permanent brachial plexus injury appear to be medically and economically unsound.

The information provided by Gherman et al is extremely important for physicians to understand. A lawsuit following BPP is commonly settled on behalf of the plaintiff, because the assumption has been made that the delivering physician did something wrong. The Gherman data clearly refute this notion and in fact promote the strong possibility that the infants who do the worst in terms of recovery of function are those who were not influenced by obstetric techniques.

Recognition of BPP in the Community Hospital

As with most neonatal conditions, the history and physical examination can usually lead to an accurate diagnosis. Information about the obstetric history and perinatal period may aid in diagnosing the type and severity of injury and perhaps assist in predicting the prognosis. The physical exam should be complete and all extremities checked, not just the apparently affected one. The sternocleidomastoid should be carefully palpated for contracture or pseudotumor. Shortening or bulging of the sternocleidomastoid may impinge on plexus nerves and cause atonia of the ipsilateral extremity.

Fractures of the ribs, humerus, or clavicle as well as other soft tissue injuries with resultant swelling in the neck and shoulder region should be ruled out with plain radiographs. Swelling as a result of these injuries can yield a pseudoparalysis which can sometimes appear as a BPP. This finding would most likely be associated with total BPP. Infectious processes about the shoulder girdle also mimic BPP.

The baby should be checked carefully for abdominal asymmetry which could indicate paralysis of the hemidiaphragm, a significant prognostic finding. Since the phrenic nerve which innervates the diaphragm is composed of fibers from C3 to C5, this finding would further aid in pinpointing the lesion. Furthermore, ocular asymmetry may indicate involvement of the stellate ganglion with the associated Horner's syndrome (ptosis, myosis, enophthalmosis, and anhydrosis) that indicate possible involvement of TI. This finding would most likely be associated with total BPP. Examination beyond that described above will usually require consultation with an orthopedist and/or a pediatric neurologist.

Management

Until relatively recently, BPP was viewed as a static condition that either recovered on its own or, if it did not, was beyond medical or surgical remediation. This view has dramatically changed and now surgical techniques have been developed that yield up to a 90% significant improvement if applied relatively early. Thus, it is important for the family physician or pediatrician caring for the infant to appreciate the need for early and appropriate intervention.

It is true that the vast majority of cases of BPP resolve spontaneously with physical therapy as the only modality of treatment. The collaborative perinatal study reported the complete return of function in 95% of the infants born with BPP. However, the situation of the other 5% is quite different. If left untreated, they may go on to develop a life long handicap of the affected extremity. As noted above, if treated early, approximately 90% of this 5% can have significant improvement. Late treatment, by contrast, yields only a 50-70% rate of improvement. These results depend not only on timing, but on the specific pathology. Obviously, if the nerves are completely severed, the outcome is not as good.

Given the above considerations, the following are offered for consideration in patient management of BPP.

1. Early recognition of BPP with referral to an appropriate treatment center ensures the best chance for a full recovery.
2. Patients must be referred to centers that have experience with this type of condition so they may be placed in the appropriate treatment protocols and given appropriate physical therapy. One hopes to avoid missing the window of opportunity for earlier, more successful, treatments.

An apparently common misconception in the state of Iowa is that no surgeons within the state have had experience in successfully dealing with BPP corrective surgery. The Department of Orthopaedic Surgery at the University of Iowa has experienced surgeons with the expertise to care for the BPP patient from birth to adulthood.

I asked Dr. Kumar Kadiyala, Assistant Professor of Orthopaedic Surgery at University Hospitals, to add a closing comment regarding management. He provided the following:

"Initial care for the BPP baby focuses on maintaining range of motion of all joints, at times with the assistance of a physical therapist, in anticipation of spontaneous recovery of neural function. This recovery occurs in the vast majority of cases. Physical examination of the infant is the most reliable method of assessing the severity of neural injury and prognosis for recovery. The presence or absence of certain motor functions in the first two to six months points to the need for surgical intervention.

Microsurgical grafting of critical components of the brachial plexus can be done in cases of root avulsion or rupture that don't recover sufficiently. Secondary procedures are also done on patients from infancy into adolescence. These secondary procedures are done far more commonly than microsurgical intervention and can also be done following microsurgical treatment. They include a variety of soft-tissue releases, osteotomies and tendon transfers to address remaining problems about the shoulder, elbow, forearm, and hand."

See related Provider Textbooks about Pediatrics.

See related Provider Topics Brain and Nervous System, Injuries and Wounds, Neurological, Pediatrics or Spinal Cord Injuries.

See related Patient Textbooks about Pediatrics.

See related Patient Topics Brain and Nervous System, Injuries and Wounds, Neurological or Pediatrics.

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