Brachial Plexus Palsy

• Brachial plexus palsy may be seen after injury to the brachial plexus during birth.
• The brachial plexus palsy is associated with stretching or contusion of the brachial plexus.
• The incidence is 2 per 1000 of births.
• The incidence has been minimized due to:
  • Modern obstetric diagnosis and care.
  • Induction of early labor when a large infant is anticipated.
  • Recognition of breech and other mal-positions by ultrasonography.
  • Delivery of these infants by cesarean section have prevented cases of traumatic vaginal delivery.

Anatomy

• The brachial plexus arises from the anterior rami of the cervical spine roots of (C5 – C6 – C7 – C8 – T1).
• The Brachial Plexus consists of ( 5 Roots – 3 Trunks – 6 Divisions – 3 Cords – 5 Terminal Branches) respectively.

Also read: Brachial Plexus Anatomy .

Risk factors for neonatal brachial plexus palsy

1. Large birth weight.
2. Breech position.
3. Forceps delivery
4. Previous delivery of a child with a brachial plexopathy.
5. Shoulder dystocia (mechanical factor that results in an upper trunk lesion).
6. Prolonged second stage of labor.

Classification

• Narakas described four categories of anatomic brachial plexus palsy involvement:

• Seddon classification for types of nerve lesions in brachial plexus injury:
  • Neurapraxia.
  • Axonotmesis.
  • Neurotmesis.
• Also there is a Sunderland classification for nerve injuries in the brachial plexus palsy.

Also read: Classification of Nerve Injuries .

Clinical Evaluation

• Decreased spontaneous movement.
• Asymmetry of infantile reflexes such as the Moro reflex or asymmetric tonic neck reflex.
• Fractures of the clavicle, humerus, and other long bones may also be seen:
  • Ipsilateral clavicular fracture is actually a favorable finding in birth-related plexopathy because the fracture allows the shoulder girdle to compress, thus decreasing overall traction on the plexus.
• With involvement of the lower plexus, the grasp reflex may be absent.
• An ipsilateral Horner syndrome consisting of ptosis, miosis, and enophthalmos, or a small pupil with a droopy eyelid, indicates injury to the T1 cervical sympathetic nerves.
• Phrenic nerve involvement is said to occur in up to 5% of upper plexus lesions

Subtypes of brachial plexus palsy:

1. Erb’s Palsy;

• The most common type injury.
• Erb’s Palsy Involves C5, C6 roots.
• Results from excessive abduction of head away from shoulder, producing traction on the brachial plexus.
• Erb’s Palsy manifested as shoulder abductor and external rotator weakness and absence of elbow flexors.
• The upper limb is positioned in adduction, internal rotation, and elbow extension. The wrist is often held in a flexed position (waiter’s tip deformity).
• Prognosis: Erb’s Palsy has the best prognosis.

2. Klumpke’s Palsy

• Klumpke’s Palsy involves C8 – T1.
• All of the small muscles of the hand (ulnar and median nerves) are paralyzed in Klumpke’s Palsy.
• Hand position: wrist in extreme extension – hyperextension of MCP – flexion of IP joints. The so called “claw hand”.
• Prognosis: Klumpke’s Palsy has a poor prognosis.
• Frequently associated with a preganglionic injury and Horner’s Syndrome.

3. Total plexus palsy

• Involves all brachial plexus roots (C5 – C6 – C7 – C8 – T1).
• There is a complete paralysis of sensory and motor functions of the entire extremity.
• Characterized by flaccid arm.
• Prognosis: it has the worst prognosis.

Differential Diagnosis

1. Fracture of the clavicle or humerus or proximal humeral physeal separation:
   • It’s manifested as diminished spontaneous movement.
   • Fracture or injury from child abuse must also be ruled out.
2. Septic arthritis of the shoulder or acute osteomyelitis.
3. Tumors involving the spinal cord or plexus (rare).
4. Congenital malformation of the plexus ( rare).
5. Post infectious plexopathy of the Parsonage-Turner type:
   • Usually results in flaccid paralysis of the muscles innervated by the involved nerves.

Treatment

Non-operative

• It’s the first line of treatment for most brachial plexus palsy.
• The aim of treatment in the initial stages is prevention of contractures of muscles and joints and awaiting return of motor function (in up to 18 months).
• Gentle passive exercises are begun to maintain full range of passive motion of all joints of the upper extremity, especially:
  • full extension of the fingers, hand, and wrist;
  • full pronation and supination of the forearm;
  • full extension of the elbow;
  • full abduction, extension, and external rotation of the shoulder.
• The use of physical therapy with casting as well as botulism toxin injections have been shown to be effective in the treatment of elbow flexion contractures.

Operative

• Nerve injury repair indications:
  1. Patients with no active biceps function by 3 months of age
  2. Age younger than 1 year.
  3. Those with nerve-level injury.
• Nerve grafting and transfer procedures:
  1. Indicated in patients with nerve root avulsions with no improvement by 3 months.

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