Brachial plexopathy, obstetric

Definition

Brachial plexopathy is any injury to the brachial plexus—the nerve bundles located on each side of the neck that give rise to the individual nerves controlling the muscles of the shoulders, arms, and hands.

Description

Brachial plexopathy occurs most often during birth, when an infant's neck and shoulders are stretched apart during passage through the birth canal. Injury to the brachial plexus is referred to by various names. Some names, such as obstetric Erb's palsy, refer to the specific region of the brachial plexus where the injury has occurred. Other more general names for the condition include:

• obstetric brachial plexus
• brachial plexus injury (BPI)
• brachial plexus palsy (BPP)
• brachial palsy in the neonate

Brachial plexus injuries

The nerves of the brachial plexus are the fifth through the eighth cervical nerves (C5, C6, C7, and C8) and the first thoracic nerve (T1). They run from nerve roots on each side of the upper spinal cord to regions beneath the collarbone where they branch out as the major nerves of the shoulders, arms, wrists, and hands.

Every brachial plexus injury is different, depending on the affected nerve or nerves and the extent and severity of the injury. There are four general types of injury, and an individual brachial plexopathy may include any or all of these injury types, on one or both (bilateral) sides of the body. The types are as follows:

• A stretch, praxis (damage), or traction (pulling or tension-creating) injury, in which the nerve has been overstretched and damaged but is not torn. Most brachial plexus injuries in newborns are of this type.
• A rupture, in which there has been a separation within a nerve. A single nerve may have more than one rupture.
• A neuroma, in which scar tissue has formed around a nerve injury. The scar tissue puts pressure on the nerve and interferes with nerve signal conduction to the muscles.
• An avulsion is the most severe form of brachial plexus injury. It is the detachment of a nerve from the spinal cord.

A minor brachial plexus injury can be a stretched nerve that results in a short-circuit in a few of the nerve fibers, causing temporary paralysis. A more severe injury may involve a complete disruption of the nerve, in which the nerve fibers around the injury become disorganized, all nerve function is lost, and scarring prevents the nerve from healing. Such an injury can result in permanent paralysis.

Obstetrical brachial plexopathy

Most injuries to the brachial plexus during birth involve the C5 and C6 nerve roots, affecting the movement of the shoulder, upper arm, and elbow. Limited shoulder motion can affect the function and strength of the hand. Obstetrical brachial plexopathies are classified according to the extent of the injury.

ERB'S PALSY Obstetric Erb's palsy is an injury in the upper brachial plexus involving C5 and C6 and sometimes C7. It usually affects the upper arm and the rotation of the lower arm. Erb's palsy is known also by the following names:

• Erb's paralysis
• Duchenne's paralysis
• Erb-Duchenne palsy or paralysis
• Duchenne-Erb syndrome or paralysis
• upper brachial plexus palsy or paralysis, Erb-Duchenne type

KLUMPKE'S PALSY Klumpke's palsy or Klumpke's paralysis is an injury to the lower brachial plexus: C7, C8, and sometimes T1. Children with Klumpke's palsy have normal use of the shoulder and elbow but weakness or paralysis in the hand and fingers. An infant also may have a drooping eyelid on the opposite side of the body from the affected hand.

TOTAL PLEXUS PALSY Also called Erb/Klumpke palsy, total plexus palsy involves all of the nerve roots of the brachial plexus to at least some extent. The entire upper extremity is affected.

Demographics

It is estimated that in North America between one and three of every 1,000 newborns are affected to some extent by brachial plexopathy. It appears to be less common than in the past, due to improvements in infant delivery methods and the increased use of cesarean sections (c-sections) to surgically remove the infant through the abdomen. However, some physicians are concerned that the late 1990s and early 2000s trend toward decreasing elective c-section deliveries will result in more cases of brachial plexopathy among newborns.

Erb's palsy is the most common type of obstetric brachial plexopathy. Total plexus palsy accounts for about 10 percent of obstetric brachial plexopathies and Klumpke's palsy accounts for less than 1 percent.

Causes and symptoms

Causes

Brachial plexopathy can result when the following events occur. An individual brachial plexopathy may include any or all of these injury types, on one or both (bilateral) sides of the body. The events are as follows:

• An infant's shoulder becomes stuck on the mother's pelvic bone during birth; the infant's neck may be stretched and the brachial plexus injured as the physician pulls on the baby to free it before circulatory or respiratory stress occurs.
• An infant's head and neck are pulled to one side while the shoulders pass through the birth canal.
• There is excessive stress on the infant's shoulders during a head-first delivery.
• There is pressure on the infant's raised arms during a breech (feet-first) delivery.
• An infant's shoulder is too large to fit easily through the birth canal (shoulder dystocia). An individual brachial plexopathy may include any or all of these injury types, on one or both (bilateral) sides of the body. (However, the association between brachial plexopathy and shoulder dystocia is controversial, with some studies indicating that 4 to 40 percent of shoulder dystocias result in brachial plexopathy and other studies finding no evidence of an association.)

Causes of brachial plexopathy, other than injuries during birth, include:

• any trauma or injury to the brachial plexus, such as might occur with vehicular accidents, sports injuries , puncture wounds , or surgery
• congenital abnormalities that affect the cervical ribs
• pressure from tumors in the region
• damage from radiation therapy
• exposure to some toxins, drugs, or chemicals

RISK FACTORS Although brachial plexus injuries can occur during any birth, there are particular risk factors. The highest rates of brachial plexus injury (7.8%) occur in newborns weighing over 10 lb (4.5 kg) who are born by assisted vaginal delivery to diabetic mothers. Premature and underdeveloped newborns are at a decreased risk for brachial plexopathy. Other risk factors for this injury are as follows:

• Some 50–70 percent of brachial plexus injuries occur in larger-than-average newborns, usually those over 7.7 lb (3.5 kg).
• About 44 percent of brachial plexopathies occur in newborns who experienced fetal distress.
• Breech deliveries increase the risk of brachial plexopathy by 175-fold, often causing bilateral injuries to the lower nerve roots of the brachial plexus.
• Prolonged labor and difficult or abnormal labor or delivery increase the risk of injury.
• Use of forceps or a vacuum device to deliver a baby increases risk.
• Injuries occur more frequently in births to mothers who have had several prior births.
• A mother who has had previous brachial-plexus-injured infants is at a 14-fold-increased risk of having another infant with brachial plexopathy.

Symptoms

The symptoms of brachial plexopathy vary greatly depending on the extent and severity of the damage. Some children with brachial plexopathy have the following limitations:

• They have no feeling or muscle control in the arm or hand.
• They can move their arm but have little control over the wrist and hand.
• They can use their hands normally but cannot use their shoulder or elbow muscles.

Typical symptoms that may be recognized at birth or shortly thereafter include the following:

• lack of spontaneous movement in the upper or lower arm or hand
• weakness in an arm
• weak or no grip
• no Moro reflex (a startled response when an infant's head drops suddenly, characterized by spreading the arms with the palms up and fingers flexed; as the reflex ends, the arms return to the body and the elbows flex and relax)
• weak or absent normal infant position with the arm flexed at the elbow and held against the body
• a limp or paralyzed arm
• lack of sensation in the arm or hand (a completely flaccid arm or part of an arm indicates an avulsion injury)

Other common symptoms of brachial plexopathy include:

• limited range-of-motion (ROM) in the arm or part of the arm
• sensation changes in the arm
• weakness in specific muscle groups
• inability to perform typical movements
• inability to bear weight in the arm
• neglect of the arm
• atypical positioning of the arm
• developmental delays
• torticollis (a shortened neck muscle, causing the head to tilt to one side)

Additional symptoms of brachial plexopathy include:

• arm pain
• facial paralysis on the affected side
• inability to sit up without assistance
• inability to crawl without a therapeutic device

Symptoms of Erb's palsy include:

• decreased abduction (turning outward) and external rotation of the shoulder
• decreased elbow flexion (bending)
• decreased supination (rotation of the forearm so that the palm of the hand is turned forward or upward)
• grasp reflex but no biceps reflex
• normal hand movement but abnormal Moro reflex
• sensory deficits
• paralysis of the diaphragm on the affected side in about 5 percent of Erb's palsy cases

Symptoms of total plexus palsy include:

• paralysis extending from the shoulder to the hand with no grasp reflex
• sensory loss
• Horner's syndrome (pupil contraction, receding eyeball, and sometimes inability to sweat on the affected side of the face) in about one-third of total plexus palsy cases

When to call the doctor

Although obstetric brachial plexopathy usually heals quite rapidly on its own, the infant may begin physical therapy within the first two weeks of life and should be evaluated by a specialist, such as a pediatric neurologist, by six weeks of age.

Diagnosis

A newborn lacking movement in an arm is examined first for fractures of the collarbone, ribs, humerus (the long bone of the upper arm, extending from the shoulder to the elbow), and even the femur (thighbone), as well as dislocations of the shoulder or elbow. Symptoms of such fractures and dislocations may be similar to those of brachial plexopathy and can cause infants to not move their arms. Those at risk for obstetric brachial plexopathy are also at risk for fractures and dislocations during birth. An infant who is not moving a fractured arm because of the pain will still exhibit a Moro reflex. However, when the infant is rolled from side to side, a brachial-plexopathy-affected arm may flop.

Brachial plexopathy is diagnosed by the following:

• an unpredictable or patchy pattern of sensory, motor, and reflex dysfunction in the arm
• x rays that rule out other causes for the symptoms
• a nerve conduction velocity (NCV) test detecting nerve damage (An electrode on the skin stimulates the nerve with a mild impulse and other electrodes record the resulting electrical impulse; the distance between the electrodes and the time the impulse takes to travel determines the conduction velocity; below-normal nerve conduction may indicate damage to the nerve.)
• electromyography (EMG) measures of the muscle response to nerve impulses (A needle electrode is inserted through the skin into the muscle and records the electrical activity of the muscle; EMG can reveal loss of nerve activity within one week of birth and can help determine which nerves are damaged.)
• magnetic resonance imaging (MRI; use magnets and radio waves to obtain images) of the brachial plexus determining the location and type of injury (MRI can be performed when the infant reaches two to three months of age.)
• computed tomography (CT) or computed axial tomography (CAT) scans performed at two to three months of age to reveal injury (CT scans use a thin, rotating x-ray beam to obtain an image as the x rays pass through body parts.)
• myelograms (x rays or CT scans taken after a dye is injected into the spinal fluid) revealing the fluid space surrounding the spinal cord in the neck (Although they may help to determine the location and type of nerve injury, myelograms generally have been replaced by MRI scans of the brachial plexus due to false positives and the invasiveness of procedure.)

Treatment

Nerve regeneration in newborns occurs at 1.8 mm. per day. Therefore, stretch or praxis injuries to the brachial plexus usually heal on their own within about three months, leading to complete recovery. However, many children with brachial plexopathy require treatment. Specialists who may become involved in a child's treatment include:

• physical therapists
• occupational therapists
• neurologists
• pediatric neurosurgeons
• orthopedic surgeons
• plastic surgeons

Physical therapy

Gentle massage and range-of-motion (ROM) exercises usually are initiated immediately, even in infants with very mild brachial plexopathy. Therapy regimes are individualized for each child, depending on the specific injury and its effects.

Treatment for brachial plexopathy may include a combination of exercises and focused physical, occupational, and aquatic therapies. Typically the therapist teaches the child's family to perform the following:

• position the infant properly
• never lift the child under the armpits
• perform passive range-of-motion (PROM) exercises on the infant
• assist with weight-bearing activities, even in a newborn
• help the infant avoid atypical movement patterns
• help thwart the infant's tendency to neglect the affected region
• detect muscle contractions even when no movement is evident
• help avoid tightening of the infant's muscles
• make adaptive equipment for the infant

At home parents may be instructed to do the following:

• perform ten repetitions of all prescribed PROMs two to three times daily
• begin gentle movements with the child's forearm rotated and the palm upward or forward (supination) to increase joint flexibility and muscle tone
• perform joint compression and weight-bearing exercises throughout the affected extremity
• practice aquatic exercises as prescribed
• practice tactile stimulation on the affected extremities, using textured materials, soft balls, vibration, and massage to increase sensory awareness
• actively involve the affected extremity in developmentally appropriate activities to increase strength and coordination, working first without the effects of gravity and later working against gravity
• place pillows or stuffed animals under the child's armpit or along side the affected arm during rest or sleep to obtain a sustained stretch

Play therapy

Play therapies are used to extend ROM from six months of age on in children with brachial plexopathy. General body activities include:

• any activity that forces the child to reach
• any activity that puts pressure on the affected arm or hand
• playing while lying on the stomach
• stacking empty boxes
• playing circle games
• playing "Simon says"
• "making angels" while lying on the floor
• throwing a beach ball overhead
• riding a tricycle or bicycle
• playing and walking in water
• climbing on play equipment
• climbing and sliding down a slide

Activities to increase hand coordination include:

• folding paper napkins
• copying and drawing basic shapes
• using scissors, paste, or toy tools
• painting
• writing on a chalkboard
• sewing cards
• playing with toys in the sink or tub
• playing with wooden puzzles, dominoes, Legos, or blocks
• stringing beads
• rolling dough
• playing in sand
• throwing a soft ball
• picking up and sorting small objects

Surgery

About ten percent of brachial plexus injuries in infants require surgery. Children with total plexus palsy who have not improved by three months of age and children with Erb's palsy who cannot strongly bend their elbow or raise their shoulder by six months of age are candidates for exploratory surgery to examine the nerve damage and perform possible nerve grafting. Surgeries are most successful if performed when the child is five to seven months of age. Surgeries are less likely to be successful if performed after 12 months of age.

Rupture injuries usually require surgery. Avulsion injuries require surgery to reattach the nerve root to the spinal cord. Surgeries that may be performed by a pediatric neurosurgeon include:

• neuroplastysurgery to repair the nerve, including stretching the nerve to relieve tension or reconnecting torn nerves
• neurolysis to destroy damaged nerve tissue or to loosen or remove scar tissue (neuroma) around the nerve
• nerve grafting by transplanting nerves from another part of the body, such as the ankle, to bridge a torn nerve or to reconnect the nerve root after an avulsion injury

Other types of surgery include:

• muscle surgery on a child aged 18 to 24 months if physical therapy has not restored shoulder rotation
• muscle or tendon transfer surgeries to restore function (For example, a child without elbow function might have a leg muscle transferred to the elbow and attached to the nerves.)
• muscle transfer surgeries in which the muscles are rearranged in an attempt to prevent permanent abnormalities
• plastic surgeries

A variety of other surgical procedures may be considered depending upon the specific situation. At least 90 percent of children improve following surgery. Exercise and massage are eventually reinitiated, depending on the type of surgery.

Other treatments

Other treatments for brachial plexopathy can be used. For example, various types of splints are available to position and support the extremity during activities and to increase weight-bearing ability. Also, casts are sometimes used to allow the nerves to heal. Finally, electrical stimulation, in conjunction with EMG, can deliver a small amount of electrical current to the muscle to prevent atrophy; it may be performed either by a therapist or at home. The child is examined regularly, both during and after treatment, for muscle recovery and proper joint development.

Prognosis

About 85 percent of infants with brachial plexopathy make a complete neurological recovery within three to six years. One study of 59 children found that 88 percent recovered by four months of age, 92 percent recovered by 12 months, and 93 percent recovered by 48 months. In another study of 28 infants with damage to the upper brachial plexus and 38 infants with total plexus palsy, 92 percent recovered spontaneously.

However, the prognosis for an individual brachial plexopathy depends on the location, severity, and extent of the damage and may be difficult to predict. In general, damage to the nerve sheath (outer covering) alone has a good prognosis. Praxis-type injuries, in which the nerve is damaged but not torn, usually improve within three months and eventually heal completely. Stretch injuries heal on their own, with 90 to 100 percent of function returning within one to two years. Severed nerves, particularly avulsion injuries in which the nerve is severed at the root, have poorer prognoses. In severe cases there may be permanent partial or total loss of nerve function in the affected nerves and weakness or paralysis of the arm may be permanent.

Erb's palsy has the best prognosis since, although shoulder, elbow, and forearm function may be affected, the hands and fingers are not affected. However, infants with Erb's palsy that involves C7 as well as C5 and C6 have a poorer prognosis. In addition Erb's palsy may lead to secondary deformities as the child grows. The most common problem is internal rotation contracture (permanent muscle contraction) of the shoulder.

Complete recovery from brachial plexopathy may be difficult to define. A Swedish study found that about 30 percent of children who had recovered the use of their shoulder, biceps, and hand by the age of three months still had disabilities at age five, including a weakened hand grip or difficulty dressing or running. The delay in normal functioning caused by brachial plexopathy and any muscle imbalances across a joint can have a major impact on the child's growing skeleton and can result in permanent muscular-skeletal abnormalities.

Long-term effects of brachial plexography may include:

• a weak shoulder girdle
• muscle atrophy
• joint contractures
• a bent elbow (called Erb Engram) with shoulder adduction (pulled in toward the body)
• impaired limb growth
• progressive bone deformities

Prevention

The primary prevention for obstetrical brachial plexopathy is the avoidance of a potentially difficult delivery by choosing cesarean section . Failure to anticipate a particularly large baby before delivery is an important risk factor. Some physicians suggest that women whose previous children had shoulder dystocia should be offered an elective cesarean delivery. However, cesarean deliveries also have risks associated with them, and it appears that increasing the frequency of c-sections would prevent few cases of brachial plexopathy since large-scale studies have shown that 3 percent of brachial plexus injuries occur during cesarean deliveries.

The use of an epidural (local) anesthetic during labor may contribute to the risk of brachial plexopathy since the anesthetic decreases the mother's ability to push during labor and may force the physician to use forceps or a vacuum device to pull the baby out.

Parental concerns

Promoting recovery

Although exercises required to treat brachial plexopathy in infants may be painful, they are essential for preventing much more serious pain and suffering as the child grows. In addition to performing prescribed massage and ROM exercises, parents should:

• always first offer objects or food to the child's affected side
• not allow the child to use compensatory movements, particularly those involving the trunk of the body
• have the child use the unaffected arm as a guide for the affected one so that the affected arm experiences what the unaffected arm is doing

Parents should help their child to become self-sufficient in the movements involved in the following daily tasks:

• toileting
• personal hygiene
• dressing
• performing simple household chores such as picking up toys, cleaning a room, or setting a table

Daily activities that increase ROM are essential even if the child is seeing a physical therapist. Parents should do the following:

• encourage a consistent daily routine and participation in activities
• try to incorporate therapy into daily play and other activities
• have the child participate in play activities that increase ROM for 15 to 30 minutes twice a day
• provide enjoyable and challenging activities
• encourage movement and use of affected joints
• encourage the child to focus on using the affected arm
• focus on the child's abilities rather than lack of abilities
• avoid doing something for the child simply because the child finds it difficult
• reward the child with verbal praise or a treat for attempting or initiating an activity
• allow the child enough time for each activity

Activities

Numerous activities have been found useful for promoting a child's recovery. Activities to increase shoulder flexibility include:

• placing and removing objects from a board or mirror
• popping bubbles
• rolling out dough with a rolling pin
• raising a dowel over the head
• playing basketball

Activities to increase shoulder abduction (movement of the arm away from the body) include playing bird or airplane and turning a jump rope.

Activities to increase elbow flexion (bending) include:

• bringing food items from hand to mouth
• using big jacks or chew toys
• talking into a play microphone
• playing a musical instrument

Activities to increase elbow extension include crawling and reaching out for objects.

Activities to increase wrist extension include:

• shaking rattles
• pulling pegs from a pegboard
• knocking on a door
• playing drums or a xylophone
• banging with a hammer
• splashing water
• painting

KEY TERMS

Abduction —Turning away from the body.

Adduction —Movement toward the body.

Avulsion —The forcible separation of a piece from the entire structure.

Brachial plexus —A group of lower neck and upper back spinal nerves supplying the arm, forearm and hand.

Cervical nerves —The eight pairs of nerves (C1C8) originating in the cervical (neck) region of the spinal cord.

Cesarean section —Delivery of a baby through an incision in the mother's abdomen instead of through the vagina; also called a C-section, Cesarean birth, or Cesarean delivery.

Computed tomography (CT) —An imaging technique in which cross-sectional x rays of the body are compiled to create a three-dimensional image of the body's internal structures; also called computed axial tomography.

Contracture —A tightening or shortening of muscles that prevents normal movement of the associated limb or other body part.

Dystocia —Failure to progress in labor, either because the cervix will not dilate (expand) further or because the head does not descend through the mother's pelvis after full dilation of the cervix.

Electromyography (EMG) —A diagnostic test that records the electrical activity of muscles. In the test, small electrodes are placed on or in the skin; the patterns of electrical activity are projected on a screen or over a loudspeaker. This procedure is used to test for muscle disorders, including muscular dystrophy.

Erb's palsy or paralysis —A condition caused by an injury to the upper brachial plexus, involving the cervical nerves C5, C6, and sometimes C7, affecting the upper arm and the rotation of the lower arm.

Flexion —The act of bending or condition of being bent.

Klumpke's palsy or paralysis —A condition caused by an injury to the lower brachial plexus, involving the cervical nerves C7 and C8, and sometimes the thoracic nerve T1, causing weakness or paralysis in the hands and fingers.

Magnetic resonance imaging (MRI) —An imaging technique that uses a large circular magnet and radio waves to generate signals from atoms in the body. These signals are used to construct detailed images of internal body structures and organs, including the brain.

Moro reflex —A startle response in a newborn, characterized by spreading the arms with the palms up and fingers flexed; the reflex usually disappears by two months of age.

Nerve condition velocity (NCV) —Technique for studying nerve or muscle disorders, measuring the speed at which nerves transmit signals.

Neurolysis —The destruction of nerve tissue or removal of scar tissue surrounding a nerve.

Neuroma —Scar tissue that forms around a nerve; a tumor derived from nerve tissue.

Neuroplasty —Surgery to repair nerves.

Palsy —Uncontrolable tremors.

Total plexus palsy —Erb/Klumpke palsy; a condition resulting from injury involving all of the brachial plexus nerves and affecting the entire upper extremity of the body.

If a child has no hand function, double sided Velcro can be placed around the hand and used to hold rattles and toys with Velcro attached to them. An older child can use a Velcro mitt and balls.

Support groups

There are numerous support groups across the United States for the families of children with Erb's palsy and other brachial plexopathies. Support groups offer encouragement and advice on the following topics:

• coping with pain and crying during therapy
• coping with daily routines
• play therapies and other activities
• sibling issues
• daycare and school
• social issues facing the child

Resources

BOOKS

Gilbert, Alain, ed. Brachial Plexus Injuries. London: Martin Dunitz, 2001.

PERIODICALS

Bavley, Alan. "Birth Injury Begins to Receive More Attention." Kansas City Star (May 7, 2000).

ORGANIZATIONS

Brachial Plexus Palsy Foundation. 210 Spring Haven Circle, Royersford, PA 19468. Web site: <http://membrane.com/bpp>.

Erb's Palsy Lawyers Network. Web site: <www.erbspalsy.com/index.htm>.

National Brachial Plexus/Erb's Palsy Association Inc. PO Box 23, Larsen, WI 54947. Web site: <www.nbpepa.org>.

National Institute of Arthritis and Musculoskeletal and Skin Diseases. National Institutes of Health, 1 AMS Circle, Bethesda, MD 20892–3675. Web site: <www.nih.gov/niams>.

United Brachial Plexus Network. 1610 Kent St., Kent, OH 44240. Web site: <www.ubpn.org>.

WEB SITES

"About Erb's Palsy." The Erb's Palsy Lawyers Network, 2004. Available online at <www.erbspalsy.com/about.htm> (December 24, 2004).

"Brachial Plexus." Hyman-Newman Institute for Neurology and Neurosurgery. Available online at <www.nyneurosurgery.org/brachial_intro.htm> (December 24, 2004).

"Brachial Plexus Birth Injury." Pediatric Orthopedics, 2000. Available online at <www.pediatric-orthopedics.com/Treatments/Brachial_Plexus/BrachialLink/Brachial_Lecture/brachial_lecture.html> (December 24, 2004).

"Erb's Palsy/Brachial Plexus Play Therapy Exercises." United Brachial Plexus Network, 2000. Available online at <www.ubpn.org/resources/playtherapy.html> (December 24, 2004).

"Frequently Asked Questions." National Brachial Plexus/Erb's Palsy Association. Available online at <www.nbpepa.org/faqs.htm> (December 24, 2004).

Stormet, Margaret. "Protocol for Treatment of Brachial Plexus/Erb's Palsy." National Brachial Plexus/Erb's Palsy Association. Available online at <www.nbpepa.org/protocol.htm> (December 24, 2004).

Margaret Alic, Ph.D.