- 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.
- 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
- Large birth weight.
- Breech position.
- Forceps delivery
- Previous delivery of a child with a brachial plexopathy.
- Shoulder dystocia (mechanical factor that results in an upper trunk lesion).
- Prolonged second stage of labor.
- Narakas described four categories of anatomic brachial plexus palsy involvement:
|Group I (Duchenne-Erb’s Palsy)||C5-C6||– Upper plexus lesions ( C5 and C6)|
– They are recognized by weakness of the shoulder abductors, external rotators, elbow flexors, and wrist extensors.
|Group II (Intermediate Paralysis)||C5-C7||– C5 – C6 – C7 |
Lack of elbow extension.
– Associated with weaker shoulder adductors.
|Group III (Total Brachial Plexus Palsy)||C5-T1||– C5 – C6 – C7 – C8 – T1|
– Flail extremity without Horner’s syndrome.
|Group IV (Total Brachial Plexus Palsy with Horner’s syndrome)||C5-T1||– C5 – C6 – C7 – C8 – T1|
– Flail extremity with Horner’s syndrome.
- Seddon classification for types of nerve lesions in brachial plexus injury:
- Also there is a Sunderland classification for nerve injuries in the brachial plexus palsy.
Also read: Classification of Nerve Injuries .
- 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.
- 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.
- Septic arthritis of the shoulder or acute osteomyelitis.
- Tumors involving the spinal cord or plexus (rare).
- Congenital malformation of the plexus ( rare).
- Post infectious plexopathy of the Parsonage-Turner type:
- Usually results in flaccid paralysis of the muscles innervated by the involved nerves.
- 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.
- Nerve injury repair indications:
- Patients with no active biceps function by 3 months of age
- Age younger than 1 year.
- Those with nerve-level injury.
- Nerve grafting and transfer procedures:
- Indicated in patients with nerve root avulsions with no improvement by 3 months.