Neonatal Brachial Plexus Palsies 

Updated: Sep 06, 2018
Author: Jennifer Semel-Concepcion, MD; Chief Editor: Elizabeth A Moberg-Wolff, MD 

Overview

Background

The first known description of neonatal brachial plexus palsy (BPP) dates from 1779 when Smellie reported the case of an infant with bilateral arm weakness that resolved spontaneously within a few days after birth. In the 1870s, Duchenne and Erb described cases of upper trunk nerve injury, attributing the findings to traction on the upper trunk, now called Erb's palsy (or Duchenne-Erb's palsy).[1] In 1885, Klumpke described injury to the C8-T1 nerve roots and the nearby stellate ganglion that now bears her name.

Many cases of BPP are transient, with the child recovering full function in the first week of life. A smaller percentage of children continue to have weakness leading to long-term disability from the injury. The mainstay of treatment for these children is physical and/or occupational therapy in concert with a regular home exercise program. A select few patients may benefit from surgical intervention in the early stages to improve innervation of the affected muscles. Others benefit from tendon transfers performed later to improve shoulder and (sometimes) elbow function.[2]

Numerous other nonsurgical treatments, including electrical stimulation and botulinum toxin injections, also may prove effective in the treatment of children with BPP. In view of the variability in presentation, treatment options, and outcome measures, a multidisciplinary approach to the care of the infant with BPP is recommended.

Pathophysiology

To understand the clinical presentation of brachial plexus palsy (BPP) and provide anticipatory guidance for families affected by the condition, the clinician must first know basic anatomy. As seen in the image below, the brachial plexus consists of nerves (the ventral rami) from C5-T1.

Brachial Plexus. Image courtesy of Michael Brown, Brachial Plexus. Image courtesy of Michael Brown, MD.

C5 and C6 join to form the upper trunk, C7 travels alone as the middle trunk, and C8-T1 join as the lower trunk. Each trunk divides into anterior and posterior divisions to create the cords, which then subdivide further into branches that supply the muscles of the arm. Injuries of the brachial plexus may be mild, with only temporary sequelae, or devastating, leaving the child with a flaccid, insensate arm.

Severity depends on the number of nerves involved and the degree to which each level is injured. The basic types of BPPs include the following:

  • Erb's palsy affects nerves arising from C5 and C6.

  • Upper-middle trunk BPP involves nerve fibers from C5, C6, and C7 levels.

  • Klumpke palsy results in deficits at levels C8 and T1, although many clinicians agree that pure C8-T1 injuries do not occur in infants and may be indicative of spinal cord injury (SCI).

  • Total BPP affects nerves at all levels (C5-T1).

  • Bilateral BPP demonstrates bilateral involvement.

When defining the severity of a peripheral nerve injury, differentiation between neurapraxic, axonotmetic, and neurotmetic lesions is helpful.

  • Purely neurapraxic lesions do not affect the axon itself. These lesions generally are reversible and do not leave sequelae.

  • Axonotmetic lesions involve disruption of the myelin sheath and the axon, leading to degeneration of the axon distal to the injury. The connective tissue across the lesion remains intact. These injuries improve gradually over 4-6 months, depending on the level of the lesion.

  • Neurotmetic lesions are the most severe, destroying not only the axon and myelin, but also the supporting structures across a nerve. As the proximal end of the nerve attempts to regenerate without this supportive connective tissue, a neuroma may develop. The extent of improvement in the patient's condition depends on the ultimate number of nerve fibers that reconnect distal to the neuroma. Muscle atrophy from a neurotmetic lesion begins 3-6 months after injury and by 1.5-2 years is irreversible.

Although the traditional mechanism of injury is lateral neck flexion, the upper rootlets (C5-C7) are 25% as likely to be avulsed as the lower roots (C7-T1). The upper roots (C5-C6), however, are far more likely to be ruptured (88%) because of the anatomy of the transverse processes and the degree of flexibility at that level.

The clinician must also distinguish neonatal BPP from traumatic BPP in older children and adults. The damage in neonates usually results from slow traction injuries, unlike the high-energy shearing type of trauma seen in older individuals. Not only are the latter injuries often more severe, but with similar injuries, infants show a better functional outcome.

This clinical observation is confirmed by Vredeveld and colleagues, who studied 14 infants and 19 adults with surgical evidence of complete avulsion of the C5-C6 roots or upper trunk.[3] Electromyography (EMG) showed normal recruitment of biceps and deltoid in the infants and complete denervation in the older individuals. When C7 also was torn, the infants demonstrated complete denervation. Vredeveld and coworkers attributed this observation to neonatal C7 innervation of the biceps and deltoid that subsequently was lost if the C5-C6 roots were functional.

Epidemiology

Frequency

United States

An incidence of 0.5-4.4 cases of brachial plexus palsy per 1000 full-term births has been reported; however, a review by Gilbert and colleagues reported an incidence of 0.8-1 case per 1000 births.[4]

International

Studies in France and Saudi Arabia have suggested an incidence of 1.09-1.19 cases of brachial plexus palsy per 1000 live births.

Mortality/Morbidity

The incidence of permanent impairment is 3-25%.

The rate of recovery in the first few weeks is a good indicator of final outcome. Complete recovery is unlikely if no improvement is noted in the first 2 weeks of life.

Race

Most studies have not found evidence to support a link between race and the risk of brachial plexus palsy. However, a 2007 study in New York City, by Weizsaeker and colleagues, found that being a member of the black population was independently predictive for Erb’s palsy.[5]

Sex

Eng and colleagues examined 191 infants with brachial plexus palsy.[6] Nearly half of them (49%) were male, and 51% were female.

Age

Neonatal brachial plexus palsy is noted at birth.

 

Presentation

History

When an infant is born with a brachial plexus palsy, the condition generally is apparent from birth. In a common scenario, the baby weighs over 4 kilograms and is the product of a difficult delivery to a multiparous woman, requiring the use of vacuum extraction or forceps. Upon delivery, which may involve anterior shoulder dystocia, the arm hangs loosely at the child's side. Respiratory depression may indicate an associated phrenic nerve palsy.[7]

Physical

Newborn findings

The infant with complete brachial plexus palsy (BPP; C5-T1) typically lies in the nursery with the arm held limply at his/her side. Deep tendon reflexes (DTRs) in the affected arm are absent, and the Moro response is asymmetrical, with no active abduction of the ipsilateral arm.

In children with total arm involvement, careful examination of the child's eye often demonstrates Horner's syndrome (ie, miosis, ptosis, anhidrosis), suggesting injury to the stellate ganglion.[8]

Children with intrinsic hand weakness associated with BPP generally have Horner's syndrome, and vice versa.

Respiratory status should be evaluated, since the phrenic nerve can be injured simultaneously.

The infant with an upper plexus palsy (C5-C7) keeps the arm adducted and internally rotated, with the elbow extended, the forearm pronated, the wrist flexed, and the hand in a fist. In the first hours of life, the hand also may appear flaccid, but strength returns over days to months.

The right side is injured in 51% of cases. Left BPP occurs in 45% of patients and bilateral injuries, in 4%.

The infant with a nerve injury to the lower plexus (C8-T1) holds the arm supinated, with the elbow bent and the wrist extended.

Sensation should be assessed closely, with the clinician noting any sensory loss in corresponding dermatomes.

Reflexes, typically absent in the affected limb, should be evaluated. This examination is particularly important in distinguishing BPP from hemiparesis, where reflexes may be brisk. Reflexes do not typically return in BPP except in the mildest injuries.

In the newborn nursery, it is essential that the physician carefully inspect the size of the hand and arm and the bulk of the pectoralis major muscle, along with palmar dermatoglyphics and limb range of motion (ROM), looking for clues indicating when the injury occurred. On occasion, injuries occur during gestation. In these cases, a child may, at the time of delivery, already have a smaller limb with asymmetrical palmar creases, pectoralis muscle atrophy, and/or joint contractures.

Associated injuries

The pediatrician must perform a careful examination of the infant with a BPP to look for associated injuries.

The most common associated (not causative) injuries include the following:

  • Clavicular and humeral fractures

  • Torticollis

  • Cephalohematoma

  • Facial nerve palsy

  • Diaphragmatic paralysis

Findings in older children

The root level(s) and severity of injury ultimately determine the clinical picture and, in part, the outcome as a child ages.

The older child with BPP involving the upper trunk typically has difficulty with active shoulder abduction, forward flexion, symmetrical elbow flexion, and forearm supination.

With shoulder abduction, the medial edge of the scapula often can be seen protruding above the shoulder line, a manifestation referred to as Putti sign.

The reduction in shoulder abduction is due in part to weakness of the deltoid and in part to the lack of external rotation, which is needed for the greater trochanter to slide past the coracoacromial arch.

The term "trumpet sign" describes the child's typical pattern of bringing objects to the mouth (ie, shoulder abduction accompanied by elbow flexion).

Posterior subluxation of the humeral head can develop as the internal rotators of the shoulder overpower the weaker external rotators and become contracted.

Mild shortening and atrophy of the limb are observed.

Biting of the fingernails and hands to the point of tissue damage is not infrequent (4.7%) in children with BPP and is more prevalent in children with total BPP.

The child should be reevaluated on a regular basis to ensure that scoliosis does not develop from muscle imbalance and asymmetrical motor patterns.

Causes

For many years, blame has been placed on the obstetrician when a neonate has been diagnosed with brachial plexus palsy (BPP). The assumption has been that the method of delivery and the traction applied to the head and neck during the birthing process cause the injury as the shoulder crosses the pubic arch. This theory has been supported by the fact that less than 1% of all BPP cases have been found in cesarean section deliveries.

A retrospective study by Jennett and colleagues[9] (reiterated by Allen and coworkers[10] ) questioned this assumption and noted that there are 2 separate populations of children with BPP: those with shoulder dystocia and those without it. Jennett found that 22 of the 39 children with BPP who were studied did not have documented shoulder dystocia. Rather than having the traditional risk factors listed above, these infants had an average birth weight of 2.5-3.5 kg, and most were born to young, nulliparous women.

Gherman and colleagues proposed that the brachial plexus in many cases has been stretched in utero or in the descent of the fetus and may not represent a traction injury associated with the final stages of delivery.[11] They reviewed birth records of 9071 children delivered vaginally to determine the extent of association between shoulder dystocia and BPP. A total of 40 cases of BPP were noted (17 cases without shoulder dystocia and 23 cases with associated shoulder dystocia).

When shoulder dystocia occurred, the risk of BPP was 18.3-32%. According to Gherman, the characteristics of the injury in children with BPP were different in the presence and absence of shoulder dystocia. When dystocia was present, the affected shoulder usually was anterior (81%), but in children with BPP and no shoulder dystocia, the injured shoulder often was posterior (68%). Children who did not have shoulder dystocia but who sustained BPP tended to be slightly smaller than were unaffected children, exhibited an associated clavicular fracture, and were subject to a less favorable outcome.

In 2002, the American College of Obstetricians and Gynecologists recommended cesarean delivery for fetuses with an estimated weight of 5 kg or more, to reduce the prevalence of shoulder dystocia. If practitioners were to follow the recommendation, the affect on the cesarean delivery rate would be negligible, but the shoulder dystocia rate, which in this category of births is 20%, would be reduced.

In 2003, Raio and coworkers identified an increased incidence of brachial plexus injury among fetuses weighting more than 5 kg (2.86% vs 0.85% in fetuses weighing 4.5-4.599 kg), especially fetuses that developed shoulder dystocia.[12] The authors suggested that when the estimated birth weight exceeded 4.5 kg, women should be informed of the increased risk of perinatal morbidity (including brachial plexus palsy) prior to making a decision on the mode of delivery.

Most neonatal BPP occurs in the birthing process.[13] Risk factors for this type of injury, also referred to as obstetrical BPP (OBPP), include the following:

  • Large birth weight (average vertex BPP, 3.8-5.0 kg; average breech BPP, 1.8-3.7 kg; average unaffected, 2.8-4.5 kg)

  • Breech presentation

  • Maternal diabetes

  • Multiparity

  • Second stage of labor that lasts more than 60 minutes

  • Assisted delivery (eg, use of mid/low forceps, vacuum extraction)

  • Forceful downward traction on the head during delivery[14]

  • Previous child with OBPP

  • Intrauterine torticollis

  • Shoulder dystocia

The aforementioned study by Weizsaeker and colleagues compared pregnancies and deliveries involving 45 infants with Erb’s Palsy with 90 controls.[5] The risk for the condition was higher for children whose mother had gestational diabetes. Mothers who did not have gestational diabetes but who nonetheless gave birth to children with Erb's palsy were found to have higher blood glucose values after a 50 g glucose challenge. Other variables found to be independently predictive of Erb's palsy were a long deceleration phase of labor, a long second stage, high birth weight, and high neonatal or maternal body mass. Being a member of the black population also was found to be independently predictive.

Other, less common causes of neonatal BPP include the following:

  • Neoplasm (eg, neuromas, rhabdoid tumors)

  • Intrauterine compression

  • Humeral osteomyelitis

  • Hemangioma

  • Exostosis of the first rib

 

DDx

Diagnostic Considerations

Preplexus lesions are manifestations of the effects caused by the tearing of a rootlet, root, or spinal nerve that feeds the brachial plexus; these lesions may produce the same clinical findings as brachial plexus palsy, but electrodiagnostic testing can distinguish them from BPP lesions.

Cervical spinal cord injury (SCI) may be involved. Bowel and bladder function should be assessed carefully. Magnetic resonance imaging (MRI) of the spine should be performed in any child with bilateral BPP to rule out an associated SCI.

Patients with hemiparesis should demonstrate the presence of DTRs, an absence of apparent abnormalities in EMG findings, and an exaggerated (not a depressed) Moro reflex.

Patients with hypotonia of central origin should have preserved DTRs and an absence of findings on EMG.

Amyoplasia congenita (a form of arthrogryposis) can be distinguished from BPP by rigidity of the joint and skin dimpling.

Children who have sustained humeral fracture demonstrate pseudoparalysis secondary to pain.

Anterior horn cell injury is unusual, but children with congenital varicella or congenital cervical spinal atrophy can present with a weak or flaccid arm accompanied by reduced sensation.

Differential Diagnoses

 

Workup

Laboratory Studies

Lab studies generally are not necessary for the diagnosis of brachial plexus palsy.

Imaging Studies

Until the advent of MRI, computed tomography (CT) myelography was the standard method for evaluating the integrity of the brachial plexus, and it remains arguably the most sensitive radiographic study to detect nerve root injuries. A water-soluble dye is injected intrathecally, and CT scans of the area in question are obtained. The main drawbacks to the procedure are radiation exposure, the need for sedation, a significant false-positive rate, and the lack of information on the distal brachial plexus. Some medical centers have abandoned the use of CT myelography, because direct observation during surgical exploration does not always correlate with CT myelographic findings.

High-resolution MRI is the best imaging study available for evaluating neonatal brachial plexus palsy. MRI requires no radiation exposure, is noninvasive, and provides more detail than does CT myelography. This test is most useful preoperatively to show the extent of trauma, including pseudomeningocele, and the presence of roots in the neural foramen.

While of little use in providing information on the anatomy of the brachial plexus, plain radiographs can be helpful in diagnosing hemidiaphragm paralysis from phrenic nerve involvement and fractures of the clavicle or humerus. Axillary radiographs also should be performed in children who show progressive loss of external rotation, to rule out posterior shoulder dislocation.

A retrospective study by Somashekar et al indicated that ultrasonography can be used for preoperative assessment of the postganglionic brachial plexus in neonatal brachial plexus palsy. For example, ultrasonography had 84% sensitivity for upper trunk neuroma involvement and 84% for middle trunk neuroma involvement. Ultrasonographic examination also revealed the presence of shoulder muscle atrophy in 11 of 21 children evaluated, with the imaging findings leading to nerve transfer surgery in eight of the 11 patients.[15]

Other Tests

Electrodiagnostic studies are used as an extension of the physical examination and can provide data on the severity and timing of the injury. The initial study usually is performed 2-3 weeks after injury, when signs of denervation are seen in children with moderate or severe injuries. Some authors feel that EMG provides useful information to track the reinnervation process and guide in surgical decision-making. Others feel that EMG does not provide prognostic information.

The examination typically includes study of latencies of musculocutaneous and axillary nerves in Erb's palsy. In complete injuries, motor and sensory nerve conduction studies (NCS) of median, ulnar, and, on occasion, radial nerves are performed. Sensory NCS are useful in discerning an avulsion injury; if the sensory nerve potential is intact in the context of a clinically insensate arm, an unfavorable prognosis is suggested. If respiratory distress was noted at birth, ipsilateral phrenic nerve conduction also is tested. Needle EMG is performed on muscles innervated by the affected nerve. In Erb's palsy, these muscles include the supraspinatus, deltoid, infraspinatus, triceps, and biceps; in cases of total brachial plexus palsy, the muscles tested include those above, as well as the dorsal interossei and opponens pollicis.

 

Treatment

Rehabilitation Program

Physical Therapy

The rehabilitation of children with brachial plexus palsy (BPP) must begin in infancy to achieve optimal functional returns. For the first 2 weeks, the child may have some pain in the affected shoulder and limb, either from the injury or from an associated clavicular or humeral fracture. The arm can be fixed across the child's chest by pinning of his/her clothing to provide more comfort. However, some authors have discouraged this pinning in favor of immediate institution of gentle ROM exercises. Parents should be instructed in techniques for dressing the child to avoid further traction on the arm. Often a wrist extension splint is necessary to maintain proper wrist alignment and reduce the risk of progressive contractures.

Therapy is the cornerstone in the management of the symptoms of a child with BPP. The role of the treating physician is to guide the program and make critical decisions regarding the need for further medical or surgical intervention. As the child gets older, bimanual activities (eg, swimming, basketball, wheelbarrow walking, climbing) should be encouraged. A comprehensive therapy program that has been designed and implemented by a pediatric physical therapist is essential for children whose case is being managed conservatively, as well as for children who require surgical intervention.[16]

A pediatric physical or occupational therapist's role is 2-fold. The first responsibility of the therapist is to provide ongoing therapeutic treatment and parental instruction. By the very nature of therapy, the therapist's second function is to provide precise and ongoing assessment of the infant's functional status and recovery, to assist the physician in determining future medical and surgical considerations, and to assess the efficacy of these interventions.

When dealing with infants and young children, the pediatric therapist should evaluate the child based on normal development and age-appropriate skills. The therapist's initial evaluation of an infant with BPP should include specific details about passive and active ROM, the strength of each muscle or muscle groups, and the posture of the affected limb compared with the other extremity, as well details regarding sensibility and overall function.

Formal goniometry should be employed to measure active and passive ROM. Standardized strength testing, although difficult in young children, is necessary for objective documentation of recovery. Physical therapists at the Hospital for Sick Children of Toronto have devised a simple observation tool that evaluates active joint movement against gravity. Based on observations of movement, a clinical grade is assigned to quantify the patient's status, and progress can be tracked over time. Comparison of the movement patterns of the affected and unaffected arm also is useful. Testing of sensation, posture, and functional activity is performed through clinical observation.

A comprehensive therapy program should consist of ROM exercises, facilitation of active movement, strengthening, promotion of sensory awareness, and provision of instructions for home activities. Overall goals should focus on minimizing bony deformities and joint contractures associated with BPP, while optimizing functional outcomes.

Severe contractures should be avoidable with consistent therapeutic exercises, including passive and active stretching, flexibility activities, myofascial release techniques, and joint mobilization.

Over time, these contractures can lead to progressive bony deformity and shoulder dislocation. Early and consistent stretching of internal rotators should minimize the risk of this problem. External rotation, performed with the shoulder adducted alongside the chest and with the elbow flexed to 90°, provides maximum stretch of internal rotators (specifically, the subscapularis) and the anterior shoulder capsule. The scapula should be stabilized while stretching shoulder girdle muscles to maintain mobility and preserve some scapulohumeral rhythm. Early development of flexion contractures at the elbow is common and can be exacerbated by radial head dislocation caused by forced supination. Aggressive forearm supination, therefore, should be avoided.

Active mobility and strengthening initially are facilitated through age-appropriate developmental activities. As the child gets older, standard strengthening exercises are used and specific functional skills are introduced. Specific muscle groups can be targeted for strengthening through functional movement. Compensatory and substitute movements should be avoided, as they may perpetuate weak muscles and deformity.

Static and dynamic splinting of the arm is useful to reduce contractures, prevent further deformity, and in some cases, assist movement. Commonly prescribed splints include resting hand and wrist splints, elbow extension splints, dynamic elbow flexion and supinator splints. Careful selection and timing of splint use is essential to optimization of the desired effect.

Taping techniques may be used by the therapist to control scapular instability and hence to promote improved shoulder mobility.

Sensory awareness activities are useful for enhancing active motor performance, as well as for minimizing neglect of the affected limb. Use of infant massage and drawing visual attention to the affected arm can be incorporated easily into play and daily activities. Weight-bearing activities with the affected arm in all positions not only provide necessary proprioceptive input but also can contribute to skeletal growth.

Instructing parents and family in a home exercise program is instrumental in effective management of BPP cases. A comprehensive program that includes stretching exercises, safe handling and early positioning techniques, developmental and strengthening activities, and sensory awareness should be developed and updated as needed. In older children with persistent disability, the focus on home instruction shifts to independence, with these patients learning self-stretching and strengthening exercises, as well as strategies for achieving specific life skills. The focus of therapy often is directed toward more recreational activities, such as swimming or basketball.[17]

Occupational Therapy

See Physical Therapy.

Recreational Therapy

Bimanual recreational activities, such as swimming, basketball, wheelbarrow walking, and climbing, should be encouraged.

Medical Issues/Complications

Aggressive forearm supination can lead to radial head dislocation. Unlike nursemaid's elbow, radial head dislocation does not relocate easily in children with brachial plexus palsy (BPP) and can lead to a permanent elbow flexion contracture.

A small, but significant, percentage of children mutilate their fingers and hands as toddlers. Parents should be warned of this possibility, and they should take care to avoid cutaneous infection.

Without regular stretching, the child with residual weakness from BPP is at risk for progressive contractures, posterior shoulder dislocation, and agnosia of the affected limb.

Scoliosis can develop from muscle imbalance and asymmetrical motor patterns.

Surgical Intervention

Early surgery/neurosurgical intervention

By the early 1900s, surgeons began performing exploratory surgery on children with brachial plexus palsy (BPP). In 1925, when Sever's series of 1100 cases failed to show significant functional benefit, interest in neurosurgical intervention faded.[18] With the advent of new microsurgical techniques, renewed interest arose in the mid-1980s, and now many centers across the US, Canada, and Europe are performing these procedures for neurologic intervention in patients with BPP.[19]

Debate continues among experts in the field on the timing and indications for neurosurgical intervention.[20] On one side are physicians who believe that spontaneous recovery occurs gradually over the first few years and that early surgical intervention may be unwarranted in many cases. On the other side are physicians who feel that surgical intervention is most effective when performed when the patient is young, in some cases as young as 2 months, and that a delay in surgery results in a less favorable outcome.

Additionally, there is controversy about whether EMG provides useful prognostic information to select appropriate surgical candidates (see Other Tests).[21] Unfortunately, the lack of uniform outcome measures and of large, controlled studies has prevented this debate from being put to rest. Many authors do agree that early surgery should be considered in children who have injuries affecting the entire brachial plexus (ie, C5-T1).

Two neurosurgical options (ie, neurolysis vs excision of the neuroma and nerve graft reconstruction) exist.

Neurolysis involves removal of scar tissue while taking care to avoid damaging the underlying nerve fibers. This procedure is performed most often when nerve grafting is necessary for treatment of more extensive brachial plexus lesions. Generally, intraoperative nerve stimulation is performed to see the extent of transmission across a neuroma. Differences of opinion exist on the criteria for neurolysis. Some surgeons perform neurolysis if there is conduction across the neuroma and appropriate distal muscle contractions, while others resort to nerve grafting when the amplitude of the motor unit action potential drops 50% or more as it crosses the neuroma.[22]

In 2006, Konig and associates studied the use of intraoperative nerve conduction in the management of neuroma-in-continuity associated with upper brachial plexus palsies in 10 children.[23] The investigators found markedly better outcomes in patients without recordable compound nerve action potentials (CNAPs) who were treated with nerve resection than they did in patients with CNAPs present across the neuroma who underwent neurolysis. This report suggested that the use of nerve conduction studies has little utility when they are employed to make surgical decisions in the treatment of neuroma.

Nerve graft reconstruction involves taking a donor nerve, usually sural, and transposing it to the area of the excised neuroma. The nerve is reversed and attached (with fibrin glue or suture) proximally to a donor spinal nerve, in most cases, and then to the nerve fibers distal to the excised neuroma. The arm usually is immobilized for 1 month postoperatively to allow the graft to begin healing. Subsequently, gentle ROM exercises are resumed. When clinical improvement occurs, it usually is noted by 3-9 months after the operation.[24]

Nerve transfer (neurotization) is required in cases where there is not a sufficient donor nerve, as in cases of avulsion or intraforaminal rupture.[25, 26, 27] The source may be extraplexual (ie, spinal accessory) or intraplexual (ie, C5 nerve root).

Tubulization is an adjuvant technique that has been described for use with nerve reconstruction when an insufficient amount of autologous nerve graft is available. It entails using a conduit to help guide the 2 ends of a nerve together. Biologic and synthetic "tubes" have been used in the process, including vein grafts, human amniotic membrane, collagen filaments, and silicone. In 2007, Terzis and colleagues described the successful use of vein grafts in 2 infants with BPP.[28] In comparison with some other materials, the vein's wall is believed to allow diffusion of the proper nutrients for nerve regeneration, act as a barrier against the in-growth of scar, and prevent wastage of the regenerating axons.

Research has focused on the use of neurotrophic factors following brachial plexus injuries.[29, 30] Studies in laboratory animals have shown that when neurotrophic factors are administered following a brachial plexus injury, motor neuron survival is significantly enhanced in comparison with untreated controls. The investigations have concluded that this may be a useful treatment in severe brachial plexopathies, particularly when used in conjunction with reconstructive neurosurgical techniques.

A number of studies have examined outcomes of surgical intervention in patients with BPP. Gilbert and colleagues performed nerve grafts on 178 children with BPP between 1978 and 1986 and reported that their results were superior to those associated with spontaneous recovery.[31] They quoted 0% spontaneous recovery of C5-C6 and C5-C7 injuries at 5 years, compared with 80% and 45% respectively in the surgical group. As a result of their experience, they recommended surgical exploration in patients with total BPP and associated Horner or Erb's palsy if those patients do not demonstrate contraction of the biceps by 3 months.[32, 33]

Gilbert also emphasized the importance of achieving a functional hand after brachial plexus repair.[31] In infants who have extensive paralysis of the hand, a surgical repair of the lower roots at the expense of the upper roots has been recommended.

Laurent and associates performed surgery on 50 infants (aged 2-6 mo in 44 cases and 7-24 mo in 6 cases).[34] Neurolysis was performed if conduction across the neuroma was greater than 50%. In total, end-to-end repairs were performed 60 times and neurolysis was carried out 41 times. One year after surgery, the patients were reevaluated; Laurent concluded that without surgical repair, the children would not have achieved antigravity shoulder function. However, Bodensteiner and associates commented in an editorial that the claims of superior outcome were not based on substantive data and that the surgical outcome quoted was not significantly better than previously published statistics of natural recovery.

Clarke and colleagues performed neurolysis on 16 infants, 9 with Erb's palsy and 7 with total BPP.[22] The average age at the time of surgery was 10 months. The study concluded that neurolysis improves muscle grade and function in Erb's palsy patients but not in patients with total plexus palsy. The authors felt that nerve grafting might offer better functional improvement in patients with total plexus palsy. One criticism of this and several other studies has been the lack of appropriate nonoperative controls.

In 2000, Strombeck and coauthors published the first retrospective series comparing outcomes for children treated surgically and nonsurgically.[35] They analyzed 247 children with BPP of varying severity at age 5 years and compared those who had undergone surgery with those who had received conservative treatment. The groups were matched and assessed for active ROM of each upper limb joint, tactile sensibility, grip strength, and fine motor skills (with the pick-up test). The group that had undergone surgery demonstrated more shoulder movement at age 5 years, but otherwise, the groups had similar outcomes. Children who underwent surgical intervention before or after 6 months demonstrated similar outcomes. The authors discouraged using deltoid or biceps activity at 3 months as the criterion for surgical intervention and came to the conclusion that children with little or no deltoid and biceps activity at 6-9 months were more appropriate surgical candidates.

In 2003, McNeely and Drake reviewed all relevant articles from 1966-2002, with the goal of establishing evidence-based recommendations for the surgical management of brachial plexus injuries.[36] After reviewing 23 articles, the investigators reported that although surgery may be a valid treatment option, no compelling evidence showed a benefit for surgery over conservative management in birth-related brachial plexus injuries.

In 2003, Grossman and colleagues reported on the outcome of combined surgeries performed on the brachial plexus and shoulder girdle in children aged 11-29 months.[37] The surgeries included neurolysis of the upper brachial plexus with nerve grafting, subscapularis release, and Botox injections into pectoralis major and latissimus. While 3 patients required additional surgery before follow-up, all 22 patients demonstrated an improvement of at least 2 grades on the modified Gilbert scale.

In 2006, O'Brien and associates performed a retrospective analysis of 58 cases (52 of which had follow-up data) of brachial plexus surgery, including nerve grafting, neurolysis, and neurotization (nerve transfer).[38] The investigators found that repair in patients aged 6 months who had less than antigravity strength in their biceps, triceps, and deltoid produced improvement in function to at least antigravity strength in these muscles by 2-year follow-up.

Late surgery/orthopedic and plastic surgery

Late surgery for BPP most often involves tendon transfers and/or osteotomies. Tendon transfers are performed most often to improve the flexibility and active movement of the shoulder. Release followed by transfer of the preserved internal rotators (ie, subscapularis, teres major, pectoralis major, latissimus dorsi) to the weaker shoulder abductors and external rotators is most common.[39] Unless the shoulder joint is dislocated, tendon transfers often are delayed until age 2-4 years to allow for motor recovery, because the glenohumeral joint has begun taking its permanent form by this time. If the shoulder is displaced, surgical intervention is expedited in order to promote normal glenoid development. If elbow strength does not permit flexion past 90° with gravity present, surgical tendon transfers may be considered. The most common transfers include (1) triceps to biceps and (2) pectoralis major or latissimus dorsi to biceps.

Osteotomies generally are reserved for children with BPP who present at a later age, once bony changes are seen at the glenohumeral joint. In these cases, a humeral external rotation osteotomy can improve function.

Outcomes of muscle transfer procedures are discussed in several sources. Hoffer and colleagues performed muscle transfers on 8 children (average age 28 months) with posterior shoulder dislocation.[40] The latissimus dorsi and teres major muscles were released and transferred to the rotator cuff. At 3-year follow-up examinations, all children showed improved muscle strength in shoulder abduction and external rotation. Mean active shoulder abduction improved from a baseline of 84° preoperatively to 164° postoperatively. Passive external rotation improved by 62°, and radiographs showed reduction of the shoulder dislocation.

Chuang and colleagues described one technique to improve the flexibility of the shoulder in BPP.[41] As a result of cross-innervation, the existing muscle imbalance is exaggerated. The authors of this study proposed several muscle transfers for the shoulder, specifically, a release of internal rotators (ie, teres major, pectoralis major), followed by a transfer of teres major to infraspinatus and reinsertion of clavicular ends of pectoralis major laterally to augment weak muscles. In the Chuang study of 29 patients, the average age at surgical intervention was 8.5 years. The average improvement in shoulder abduction was from 77° and was 48° in external rotation.

Supination and pronation deformities may be suitable for surgical intervention, such as biceps rerouting and pronator teres lengthening, respectively. Price and associates reported good results in 20 of 21 patients who underwent these tendon transfers.[42] The supinated forearm may also be improved with a radius rotation osteotomy.

Waters and colleagues studied 48 patients prospectively with neonatal BPP to determine the outcomes of humeral derotation osteotomies and compare them with tendon transfers.[43] The patients had sequelae of internal rotation contracture, external rotation weakness, and shoulder dysfunction. CT scanning or MRI of the shoulder was performed to delineate the glenohumeral relationship. External rotational humeral osteotomies were performed on older children (average age 8.4 years) with severe glenohumeral deformity, while younger children (average age 4.9 years) with less glenohumeral pathology underwent tendon transfers (pectoralis major lengthening, latissimus and teres major transfer to the rotator cuff). In both groups, the combined Mallet score increased significantly, from 9.5 to 15.1 in the osteotomy group and from 9.5 to 15.6 in the transfer group

In 2002, Terzis and coauthors suggested that surgical correction to improve scapular stabilization may be of some functional and cosmetic benefit.[44] In a series of 26 patients, they performed a transfer of the contralateral trapezius muscle and/or rhomboids to anchor the affected scapula. In severe cases, the contralateral latissimus dorsi was also used. The investigators found improved scapular stability, as well as gains in active shoulder flexion, abduction, and external rotation.

In 2006, El-gammal and associates studied 109 obstetrical BPP patients with poor shoulder abduction and external rotation who underwent subscapularis release and transfer of the teres major to the infraspinatus, with or without pedicle transfer of the clavicular head of the pectoralis major to the deltoid.[45] Age at surgery was divided into 4 groups: younger than age 2 years, ages 2-4 years, ages 4-10 years, and older than age 10 years. Improvement in abduction averaged 64º (100%), and that of external rotation, 50º (290%), which negatively correlated with the age at surgery (P < 0.001). The investigators found that the best improvements in abduction and external rotation were obtained in patients below age 4 years, with the greatest results in the youngest group.

Assessment Tools

Mallet classification

The Mallet classification is arguably the most widely used tool to measure recovery after brachial plexus injury or subsequent surgical repair (see image below). It primarily reflects the integrity of muscles innervated by the upper brachial plexus. The arm is tested in 5 different natural movements: abduction, external rotation, hand behind head, hand to back, and hand to mouth. Scores can be affected not only by strength, but by joint contracture, bony deformity, and neglect of the affected limb.

Mallet classification. Mallet classification.

Grades II-IV are depicted in the above image. Grade I denotes no active motion and grade V reflects normal movement (equal to the contralateral limb if unaffected). Hence, aggregate scores range from 5-25.

Active Movement Scale

The Active Movement Scale was created by the Hospital for Sick Children in Toronto to assess motor function in infants with brachial plexus injuries. An infant is scored on 15 separate movements based on observational analysis. A muscle grade score of 0 (no contraction) to 7 (full motion) is assigned based on motion elicited. Fifteen movements are evaluated from the affected shoulder to the hand: shoulder abduction, adduction, external rotation, flexion, and internal rotation; elbow flexion and extension; forearm supination and pronation; wrist flexion and extension; finger extension and flexion; and thumb flexion and extension. Studies have denoted good interrater reliability with this tool.[46, 47]

Gilbert shoulder classification

See the list below:

  • Grade 0 is a complete flail shoulder.

  • Grade 1 (poor) is abduction equal to 45°, with no active external rotation.

  • Grade 2 (fair) is abduction of less than 90°, with no external rotation.

  • Grade 3 (satisfactory) is abduction equal to 90°, with weak external rotation.

  • Grade 4 (good) is abduction of less than 120°, with incomplete external rotation.

  • Grade 5 (excellent) is abduction of greater than 120°, with active external rotation.

Pediatric Outcomes Data Collection Instrument

The Pediatric Outcomes Data Collection Instrument is an established tool that measures upper extremity function, transfers and basic mobility, sports and physical function, comfort and pain, and happiness with physical condition.

In 2005, Huffman and colleagues reported on the administration of the test to 23 children with brachial plexus palsy (BPP) who were candidates for shoulder surgery.[48] The investigators found that clear differences existed between these children and age-matched controls in (1) upper extremity function, (2) sports, and (3) global function. The report concluded that the Pediatric Outcomes Data Collection Instrument may have further application as a tool to measure baseline function and postoperative functional gains for children with BPP.

Other Treatment

Neuromuscular electrical stimulation

Neuromuscular electrical stimulation (NMES) is used widely for children with BPP. NMES is a modality in which muscles are stimulated by pulsating alternating currents. The 2 main forms used are threshold and functional electrical stimulation (FES). The former can begin when the patient is young; it involves the application of low-frequency currents to the muscle. This technique has been reported to increase blood flow and possibly muscle bulk but has not been studied rigorously. FES involves stimulation with a higher-frequency current, causing the muscle to contract and the arm to move.

The stimulator needs to be titrated with assistance from the child to allow for sufficient muscle contraction and the avoidance of pain. Many children can cooperate sufficiently with this procedure by age 3 years, and the technique is helpful in prompting weak muscles to contract in functional situations. NMES has been reported in the literature as useful for facilitating muscle contraction and is used widely to minimize atrophy of affected muscles. No large studies have been published on the use of NMES with BPP, and its effect on reinnervation is not clear.

Botulinum toxin A therapy

Botulinum toxin A (BoNT-A) therapy is being used by several facilities to improve the flexibility of shoulder internal rotators. It is also used in the treatment of co-contractions, with the toxin administered to temporarily paralyze the functioning muscles/groups in order to allow weak muscles to become stronger. The usefulness of this intervention still is being studied.

A retrospective cohort study by Michaud et al supported the effectiveness of BoNT-A therapy in neonatal BPP. The study involved 59 patients with the condition, who underwent a total of 75 injection procedures in 91 muscles and/or muscle groups. Results included improvements in ROM for active and passive shoulder external rotation following shoulder internal rotator injections. In 67% of patients who received triceps injections, active elbow flexion improved and was sustained after the toxin was no longer active, and in 45% of patients who were being considered for surgery, the operation was modified, postponed, or avoided, after BoNT-A treatment.[49]

A literature review by Buchanan et al also found BoNT-A to be effective in treating neonatal BPP, with the therapy diminishing internal rotation/adduction contractures of the shoulder, flexion/extension contractures of the elbow, and pronation contractures of the forearm. However, older patients obtained less benefit from BoNT-A, according to the report.[50]

Consultations

If multidisciplinary evaluation is not available, consultations from pediatric physical medicine and rehabilitation, orthopedics, neurosurgery, and plastic surgery should be obtained for evaluation of the patient's suitability for surgical intervention.

 

Medication

Medication Summary

No studies were found to support the use of medications in the treatment of neonatal brachial plexus palsy.

 

Follow-up

Further Outpatient Care

See Rehabilitation Program.

Complications

Children with brachial plexus palsy are at risk of developing complications, such as progressive contractures, bony deformities, scoliosis, posterior shoulder dislocation, and agnosia of the affected limb.

Prognosis

Statistics on children who attain complete recovery after brachial plexus palsy (BPP) vary widely, with reports ranging from 4-93%. This discrepancy is due, at least in part, to the time of evaluation. Many children present to the newborn nursery with temporary weakness (neurapraxia) that resolves prior to discharge and is thus unaccounted for in most of these studies.

Each child with more severe injuries presents with a slightly different degree of injury and responds differently to growth and therapeutic interventions.[51] Experience in treating children teaches that children who present at 2 weeks of age with no signs of recovery generally are subject to development of sequelae, including mild scapular winging, inability to supinate the forearm fully, limitation in shoulder abduction, and forward flexion.

Peripheral nerves remyelinate at a rate of 1 mm/day. Thus, if the nerve is not transected, recovery can be expected by 4-5 months in Erb's palsy, 6-7 months for an upper-middle trunk palsy, and 14 months for a total BPP. Some authors believe that infants who do not show signs of spontaneous recovery by 3-5 months usually are left with residual deficits if managed conservatively. Papazian and associates add that unfavorable functional outcome is related more often to aberrant reinnervation than to lack of reinnervation.[52] Aberrant reinnervation is especially common in brachial plexus lesions secondary to the close proximity of the nerves involved.

As one might expect, findings consistent with a more extensive initial injury (Horner's syndrome and total BPP) portend a less favorable prognosis. The converse also is true; children with isolated upper trunk lesions generally have a better prognosis. The presence or absence of phrenic nerve involvement does not appear to have prognostic value in BPP.

Yilmaz and coworkers compared MRI, electrophysiologic studies, and muscle strength scoring in 13 infants with BPP to determine which indicator provided the most accurate prognosis of the outcome at 1 year.[21] They found that scoring of muscle strength (eg, elbow flexion; wrist, finger, and thumb extension) was the most reliable measure, with 94.8% confidence at 3 months. Electrophysiologic studies, while helpful in identifying patients with an unfavorable prognosis, occasionally are overoptimistic (in 1 of 13 cases). MRI findings of pseudomeningoceles were seen in 2 of 5 patients with an unfavorable prognosis and in 2 of 8 with a good prognosis.

A study by Buitenhuis et al found reduced sensibility of the thumb and index finger in children with neonatal BPP associated with C5 and C6, following either conservative or surgical treatment.[53]

Michelow and colleagues retrospectively studied 66 children with BPP.[54] They found that elbow flexion capacity at 3 months correlated well with good recovery of the arm at 1 year; however, predictions based on the presence or absence of elbow flexion at 3 months were incorrect in 12.8% of cases. When elbow flexion was combined with other physical findings (eg, improved extension of the elbow, wrist, thumb, finger), the prediction was incorrect in only 5.2% of cases.

Eng and associates pointed out that most patients who are treated conservatively exhibit a return of biceps function.[6] Biceps strength at 3-4 months, therefore, should not be the sole selection criterion for neurosurgical intervention. Many children did not show reinnervation of the biceps until 4-6 months of age, the forearm until 7-8 months, and the hand muscles (when affected) until 12-14 months. EMG signs of reinnervation are apparent 3-4 weeks before clinical recovery is seen. With conservative management alone, motor function continues to improve until age 2.5 years.

Eng classified sequelae as mild, moderate, and severe. Mild impairment was defined as minimal winging of the scapula, shoulder abduction to 90° or more, minimal limitation of shoulder rotation and elbow supination, normal hand function, and normal sweat and sensation.[6] Moderate impairment included moderate winging of the scapula, shoulder abduction of less than 90° with substitution by other muscles, elbow flexion contracture, no supination, weak wrist and finger extensors, good hand intrinsic muscles, and some loss of sweat and sensation. Severe impairment was defined as marked winging of the scapula, shoulder abduction less than 45°, severe elbow flexion contracture, no supination, poor or no hand function, severe loss of sweat and sensation, or agnosia of the limb.

Outcomes were followed in 149 children whose cases were managed conservatively. A total of 4% recovered completely, 62% developed mild sequelae, 19% had moderate symptoms, and 15% sustained severe impairment.

In 1999, Waters performed a retrospective analysis of 94 children with BPP, comparing outcomes following neurosurgical repair, tendon transfers, osteotomy of the humerus, and conservative management.[55] The investigators looked at 66 infants with BPP who presented in the first 3 months of life; 6 underwent microsurgical repair after no clinical improvement was seen in biceps contraction and antigravity strength at 6 months. Twenty-seven patients were referred after 6 months, secondary to persistent deficits; latissimus and teres major transfer was performed in 9 patients and a humeral derotation osteotomy in 7 for weakness in external rotation or tightness of the internal rotators.

The patients who underwent microsurgical repair had more favorable outcomes (based on the Mallet classification) than did those who did not have biceps function by 5 months, but their outcomes were not better than those who had a return of biceps function by 4 months. The Mallet scores, 4 in each category on average, after tendon transfers and osteotomy were equal to those of children who spontaneously regained biceps function in the first 3 months of life. Despite the small sample size, the investigators concluded that microsurgical repair leads to improved function in children who have not had clinical improvement of the biceps by 6 months. If biceps function by 3 months has been used as the main criterion for neurosurgical intervention, 39 additional patients would have qualified.

In 2004, Smith and colleagues concluded a 13-year prospective study that looked at the long-term outcome of patients with absent biceps function at 3 months.[56] Of the 170 patients studied, 28 had absent biceps function at 3 months. Twenty-seven of the 28 had at least antigravity biceps function at the time of follow-up. The researchers concluded that patients with C5-C6 injury and absent biceps function at age 3 months often have good long-term shoulder function without brachial plexus surgery.

Fisher and associates studied the utility of elbow flexion as a criterion to recommend nonoperative treatment for obstetrical BPP.[57] They studied 209 cases through retrospective chart review and organized them in 4 groups: Group A, no elbow flexion at 3 months (operative); Group B, elbow flexion at 3 months (operative); Group C, no elbow flexion at 3 months (nonoperative); and Group D, elbow flexion at 3 months (nonoperative). Elbow flexion was measured with the Active Movement Scale. The investigators found that Groups A, B, and C experienced a statistically significant increase in elbow function by the end of the study period (3 years), with no statistically significant differences between the 3 groups by the end of the study period. Group D showed statistically significant improvement by 3 months, compared with the other groups, leading most patients to be discharged from the clinic before the end of the 3-year study period.

Patient Education

See Physical Therapy.