Brachial Plexus Birth Palsy
Brachial plexus is formed by the union of the anterior rami of C5, C6, C7, C8, and T1.
Smellie (1764) was the first to mention paralysis of the arm resulting from injuries to the brachial plexus during delivery.
Duchenne (1872), Erb (1874), and Klumpke (1885) described the mechanism of injury and site of injury to the nerves producing the type of paralysis.
The incidence is 03 to 2.5 per 1000 live birth.
The exact cause of brachial plexus birth palsy is elusive.
The recognized risk factors are – large for gestational age, the prolonged second stage of labor, breech delivery, shoulder dystocia, difficult delivery including extraction technique, fetal distress, and previous births with brachial plexopathy.
The mechanism of injury is the stretch across the plexus (Traction lesions).
New-born with a brachial plexus injury has decreased spontaneous movement and asymmetry of infantile reflexes such as Moro’s reflex or asymmetric tonic neck reflex.
Cephalic hematoma, laryngeal nerve injuries with vocal cord paralysis, and facial nerve paralysis may be seen cases of forceps assisted delivery.
With the involvement of the lower plexus, the grasp reflex may be absent.
Cord level trauma due to root avulsion should be suspected in cases of lower limb weakness or spasticity.
Three main varieties of paralysis are recognized –
Upper arm type (Erb-Duchenne) – This results from injury to the upper trunk of the plexus.
The upper arm is by the side of the body, the forearm is pronated and the elbow is extended or slightly flexed.
During the first few days of life, there may be swelling or tenderness in the supraclavicular region.
Neurological examination shows paralysis of the deltoid, supraspinatus, elbow flexors, and brachioradialis.
Whole arm type – Less common form, with complete affection of upper extremity.
Lower arm type – Predominant injury to the lower part of the plexus (C8 %T1).
There will be paralysis of the intrinsic muscle of the hand and can produce Horner’s syndrome.
Brachial plexus birth palsy is a clinical diagnosis.
An investigation like infantogram is required to rule out bony injuries like clavicle or humerus fracture.
For the first few days after the birth, the limb should be rested to allow the hemorrhage and edema in the nerves to subside. So during the first week, no passive movement or physiotherapy is indicated.
After the first week, passive movements are indicated. At each feed, the shoulder, elbow, and wrist should be put through a full range of passive movements. This should be continued by the mother at home.
During the first several months’ careful repeated observation is needed to establish the pattern of recovery.
Attention should be paid towards the assessment of the shoulder range of movement especially maintaining the passive external rotation is critical.
Surgical exploration and nerve grafting or nerve transfer are indicated if the elbow is not recovered between 3 to 6 months.
Later treatment is indicated if motor recovery is not adequate to maintain shoulder muscle balance, early contracture release and muscle transfer to the external rotators should be considered before established joint deformity occurs.
The natural history varies and reported rates of complete recovery range from 10 to 95%.
The presence of Horner syndrome, total plexus involvement, and failure of return of function especially antigravity motor recovery by 3 to 6 months of life indicate a poor long term outcome.