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Brachial Plexus Birth Palsy :Overview

Peter M Waters MD

John E. Hall Professor

Harvard Medical School

Clinical Chief Orthopedic Surgery

Childrens Hospital

Emphasis #1 Anatomy

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The lateral cord of the brachial plexus terminates into two branches. These are the:

A lateral pectoral and suprascapular

B musculocutaneous and median

C musculocutaneous and axillary

D median and axillary

E lateral and medial pectoral

Preferred Response: B

The lateral cord terminates into MCN and lateral root of median nerve. The posterior cord terminates in axillary and radial nerves. The medial cord terminates in ulnar and medial root median nerve. The lateral pectoral arises from lateral cord but not as terminal branch. The suprascapular arises from upper trunk and medial pectoral is first branch of medial cord

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Which of the following nerves originates from the root level of the brachial plexus?

A. Upper subscapular nerve

B. Dorsal scapular nerve

C. Nerve to subclavius

D. Suprascapular nerve

E. Medial pectoral nerve

Preferred Response: BDiscussion: The dorsal scapular and long thoracic nerves originate from the roots of the brachial plexus. The presence of motor function in the rhomboids and serratus anterior, which these nerves innervate, indicates that root avulsion has not occurred at these levels, and nerve repair or graft may be possible.

The dorsal scapular nerve originates from the C5 root and the long thoracic nerve originates from the roots of C5, C6, and often C7. The subscapular nerves (upper and lower) are branches of the posterior cord. The nerve to the subclavius and the suprascapular nerve arise from the upper trunk, and the medial pectoral nerve arises from the medial cord.

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Which of the following nerve branches of the brachial plexus originates at the trunk level?

A. Lateral pectoral

B. Axillary

C. Medial pectoral

D. Long thoracic

E. Suprascapular

Preferred Response: EDiscussion: The suprascapular nerve originates from the upper trunk. The lateral and medial pectoral nerves originate from the lateral and medial cords, respectively. The axillary nerve is a terminal branch of the posterior cord. Spinal roots from C4, C5, C6, C7 and T1 contribute to the long thoracic nerve.

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Progression of Knowledge• Surgeon’s three

dimensional understanding and knowledge growing from simple two dimensional illustrations: requires desire and time

Emphasis #2 Diagnosis

• Physical Exam

• Electrodiagnostics

• Radiology

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Physical Exam• Secure with all

developmental stages: infants, children, adolescents

• Utilize neonatal reflexes, keen observation, simulated play, patience, age appropriate instruction

• Consistency: reliable and valid in repeated exams

Anatomy

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Anatomy

Anatomy

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Anatomy

Anatomy

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Anatomy

In addition to meningoceles, another magnetic resonance imaging finding consistent with nerve root avulsion is

A. avulsion of the sternocleidomastoidB. edema within the anterior scalene muscleC. spinal cord edemaD. omohyoid disruptionE. normal erector spinae muscles

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Preferred Response: CDiscussion: In contrast to CT myelography, MRI tends to underestimate the number of individual nerve root avulsions. The use of three-dimensional fast spin-echo volume acquisition provides T2 weighted images that enhance the cerebrospinal fluid in the thecal sac (MR myelography). This technique improves the detection of nerve root damage. Additional MRI findings of nerve root avulsion (spinal cord edema, syrinx, hemorrhage, absent roots, meningoceles, erector spinae denervation) can be used to increase its accuracy.

Which of the following is true regarding electrodiagnostictesting?

A. Positive sharp waves often appear earlier than fibrillation potentials.B. Positive sharp waves are not present after local muscle trauma.C. Positive sharp waves do not distinguish between neurapraxia and axonotmesis/neurotmesis.D. Fibrillation potentials are usually not associated with axonal degeneration.E. Increased insertional activity is encountered in myopathies.

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Preferred Response: ADiscussion: Positive sharp waves are thought to have thesame significance as fibrillation potentials. However, they often appear a few days earlier and both generally peak at 2 to 4 weeks after nerve injury. False negative studies may be encountered the first 7–10 days following injury. Local trauma to a muscle may result in positive sharp waves. Positive sharp waves aid in distinguishing between incomplete and complete nerve lesions. Axonal degeneration is usually associated with fibrillation potentials, which may also be found with upper motor neuron lesions and myopathies. Myopathies actually result in a decreased insertional activity.

Emphasis #3Natural History

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What does the “Review of the Literature” tell us?

Brachial plexus birth palsies are seen in

• large infants

• maternal gestational diabetes

• difficult deliveries: shoulder dystocia, forceps, vacuum extraction

• breech presentation

There may be:

• associated clavicle, humerus fractures

• confusion related to pseudoparalysis from a fracture alone or sepsis

• other neuropathic processes such as hemiparesis

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What happens to an infant with “Erb’s palsy”?

• few true natural history studies

• range of full recovery cited at 50-95% depending on primary care versus subspeciality publications, texts

• high incidence of patient loss in retrospective case series

Tassin and GilbertThis image cannot currently be displayed.

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CHMC Prospective Study• Comparison of Natural

History, the Outcome of Microsurgery Repair, and the Outcome of Operative Reconstruction in Brachial Plexus Birth Palsy. JBJS81A 1999

Mallet Classification ResultsMallet Classification Results

ABD ER Hd -Neck

Hd -Mouth

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

ABD ER Hd -Neck

Hd -Mouth

1 Month

2-3 Mos.

4 Mos.

5 Mos.

6 Mos.

Microsurg

Expected Natural History Outcomes

• Recovery by one month of life = normal function

• Recovery at two and three months of life has:– near normal recovery.

– Scapular winging universal with some limitation of glenohumeral motion.

– May need secondary tendon transfer rotator cuff in small percentage of patients

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And that…..

• Recovery biceps between three and six months has– progressive decrease in function

– increased scapular winging

– internal rotation contracture/external rotation weakness shoulder common

• Horner’s syndrome poor prognosis

• C5-C6-C7 loss poorer prognosis than C5-C6 alone

• findings consistent with most other centers

This image cannot currently be displayed.

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The best predictor for recovery in brachial plexus birth palsy is:A. the presence of a Horner's syndrome.B. the absence of pseuedomeningoceles on myelogram.C. an M2 deltoid by five months of age.D. an M1 biceps by two months of age.E. the presence of some sensation in the hand at birth.

Preferred Response: DDiscussion: Up to 90% of infants with an obstetrical palsy will recover without surgery. Biceps recovery has been a reliable predictor of further recovery. If the deltoid and biceps have not reached grade M1 by two months of age, complete recovery will be very unlikely. If initial contraction of the biceps and deltoid occur by age three months, recovery can still be good. However, if the biceps has not reached grade M3 by age five months, the outcome will be poor.

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At birth, a global brachial plexus palsy was identified. Six weeks later, the manual motor testing for the biceps and deltoid is 2/5. There has been nearfull recovery of the forearm and hand muscles. The next stage in management would be:A. ObservationB. Brachial plexus MRIC. CT MyelogramD. Operative exploration and sural nerve graftE. Ulnar fascicular nerve to musculocutaneous nerve transfer

Preferred Response: ADiscussion For OBPP, the upper trunk regeneration is followed closely in the first six months. Early recovery is encouraging and should be monitored for 3 to 6 months. Long-term studies demonstrate that a M3 bicep and deltoid at six months are indicators of sufficient natural recovery

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Emphasis #4 Nerve Surgery Indications

• assess for first 3 - 6 months of life

• record timing of biceps recovery by month of life

• Toronto score = return of elbow flexion, wrist extension, finger extension, thumb extension (<3.5 poor prognosis)

• Toronto active motion scale

• perform microsurgery at 5-6 months of age for those infants with no biceps against gravity

• Nerve transfers at 9 months for failed “cookie test”

A five-month-old, large birth weight baby presents with a motionless left upper extremity since birth. Examination showed good digit function and wrist flexion, but absent wrist extension, shoulder abduction, and elbow flexion. The next most appropriate step in management would be:

A. CT myelogramB. Exploration of the supraclavicular plexus brachial plexus. T3,T4 intercostal nerve transfer to biceps branch of musculocutaneous nerve if post-ganglionic rupture of C5 and C6 are identified at time of surgery.C. Exploration of the supraclavicular plexus. Ipsilateral spinal accessory nerve transfer to suprascapular nerve if post-anglionic rupture of C5 and C6 are identified at time of surgery.D. Observation for now with a return appointment to clinic in three months E. Exploration of the supraclavicular plexus. Bilateral sural nerve grafting of C5 and C6 nerve roots to the upper trunk if post-ganglionic rupture of C5 and C6 are identified at time of surgery.

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Preferred Response: EDiscussion: With no biceps recovery at five months of age, supraclavicular brachial plexus exploration is indicated and the results have been shown to decline if primary repair is delayed beyond six months. At time of surgery, C5 and C6 are likely to be ruptured distal to their dorsal root ganglia. In these patients, reconstruction using nerve grafts should be considered. The favored nerve autograft is the sural nerve from the posterior leg. Bilateral sural nerves are often necessary to satisfy the diameter of the upper trunk. A CT myelogram is a difficult and unnecessary procedure in this age group. A T3, T4 intercostal neurotization would be considered if the child had a C5,C6 nerve root avulsion rather than a post-ganglionic nerve root rupture. An ipsilateral spinal accessory nerve transfer to suprascapular nerve would be indicated in a patient with a C5 nerve root avulsion.

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A 6 month old baby presents with brachial plexus birth palsy, including ptosis, and absent shoulder abduction and external rotation, elbow flexion, and wrist extension. She has weak (less than anti-gravity) elbow extension, finger and thumb extension, and finger flexion. You tell her parents that the recommended treatment for her severe birth palsy is:

A. Observation and range of motion exercises until age 2 years, with brachial plexus exploration and reconstruction at that time if no further recovery has occurredB. Observation and range of motion exercises only, no surgery is indicatedC. Brachial plexus exploration and reconstruction with sural nerve graftsD. Tendon transfers to restore shoulder abduction, elbow flexion and wrist extensionE. Brachial plexus exploration and reconstruction with cross chest C7 nerve graft

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Preferred Response: CDiscussion: This infant has a poor prognosis for recovery. At age 6 months, no recovery of elbow flexion, wrist extension, and very weak finger and thumb extension are poor prognostic signs. Her treatment is controversial, but currently available data indicate that she will probably recover more strength with brachial plexus reconstruction performed prior to one year of age. Tendon transfers may not be possible with so few donor muscles available. The results of extra-plexal grafts are not as good as intra-plexalreconstruction, if possible. In most cases of obstetrical palsy, at least one nerve root is not avulsed, and is available for reconstruction.

Surgical Techniques

• Nerve Grafting

• Nerve Transfers

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UPPER TRUNK RUPTURE

• Sural grafts C5-C6 to posterior and anterior divisions upper trunk, suprscapular nerve

AVULSIONC5-C6-C7

• intercostal nerve transfers to musculocutaneous, spinal accessory to suprascapular,

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During exploration of the brachial plexus in an infant with an obstetric palsy, the spinal accessory nerve is best identified:

A. As is emerges from the sternocleidomastoid muscle.B. Adjacent to the mastoid process.C. In association with the greater auricular nerve.D. Distally, within the trapezius muscle.E. In the posterior triangle between the C4 and C5 nerve roots.

Preferred Response: EDiscussion: In obstetrical palsy, the spinal accessory nerve can be identified within the surgical field as it courses into the posterior triangle of the neck. The emergence from the sternocleidomastoid muscle, the mastoid process and thegreater auricular nerve are located too proximal out of the surgical field to be used as reference points. The arborization of the spinal accessory nerve distally in the trapezius makes it difficult to identify. In the adult, identification of the nerve within the trapezius is much easier.

References: Al-Qatttan MM, El-Shayeb A: Identification of the spinal accessory nerve within the surgical field during primary exploration of the brachial plexus in infants with obstretric palsy. J Hand Surg (Am) 30A:808-811, 2005.

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Oberlin Ulnar Motor to Biceps

Motor