Overview
Definition:
Brachial plexus birth injury (BPBI) refers to damage of the brachial plexus nerves, a network of nerves extending from the spinal cord in the neck to the shoulder, arm, and hand, occurring during childbirth due to excessive stretching or compression.
Epidemiology:
Incidence varies globally, reported between 0.4 to 3.8 per 1000 live births, with higher rates in macrosomic infants, difficult vaginal deliveries, and breech presentations
Risk factors include maternal diabetes, prolonged labor, and shoulder dystocia.
Clinical Significance:
BPBI can lead to significant motor and sensory deficits in the affected limb, impacting functional development and quality of life
Early recognition, appropriate management, and timely surgical intervention are crucial for maximizing functional recovery and preventing long-term disability, making it a high-yield topic for pediatric and neurology examinations.
Clinical Presentation
Symptoms:
Infant presents with decreased or absent movement in the affected arm
Weakness or paralysis of the shoulder, elbow, wrist, or hand
Grasp reflex may be present or absent
Pain and irritability, especially during passive movement of the limb
Loss of sensation in the arm or hand.
Signs:
Affected arm lies limply at the side
Shoulder may be internally rotated and extended
Elbow extended
Forearm pronated
Wrist and fingers flexed (Erb's palsy)
Complete paralysis of arm and hand (total BPBI)
Horner's syndrome (ptosis, miosis, anhidrosis) may be present in upper plexus injuries
Muscle atrophy can develop over time.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on history of birth trauma and physical examination findings
Electromyography (EMG) and nerve conduction studies (NCS) can confirm nerve damage and assess severity, typically performed 3-6 weeks after birth
MRI can help identify avulsion injuries or pseudotumors.
Diagnostic Approach
History Taking:
Detailed birth history including mode of delivery, presence of shoulder dystocia, birth weight, duration of labor, and any obstetric interventions
Family history of nerve disorders
Any previous infant with similar symptoms.
Physical Examination:
Systematic assessment of active and passive range of motion of all joints in the affected limb
Assessment of muscle strength using the modified British Medical Research Council (BMRC) scale
Palpation for muscle tone and tenderness
Examination for sensory deficits
Assess for presence of Horner's syndrome.
Investigations:
Electromyography (EMG) and Nerve Conduction Studies (NCS): essential for confirming nerve injury, determining the level and severity of involvement, and assessing prognosis
Typically performed 3-6 weeks post-birth
MRI: can reveal nerve root avulsions, hematomas, or neuromas
Ultrasound: may be used in the neonatal period to assess for nerve edema or injury.
Differential Diagnosis:
Fracture of the clavicle or humerus
Epiphyseal separation
Transient brachial plexus neuropraxia
Spinal cord injury
Skeletal abnormalities
Cerebral palsy
Neonatal sepsis
Congenital muscular torticollis.
Management
Initial Management:
Gentle handling of the affected limb to prevent further injury
Immobilization may be considered in the acute phase to protect the nerves
Pain management with acetaminophen or ibuprofen as needed
Avoidance of passive stretching that could cause pain or further stretch injured nerves.
Medical Management:
Conservative management forms the mainstay
Physical therapy and occupational therapy are critical, starting within the first week of life
Therapies focus on maintaining joint range of motion, preventing contractures, promoting muscle reinnervation, and developing compensatory strategies
Splinting may be used to position the limb for optimal function and prevent deformities.
Surgical Management:
Surgical intervention is considered for persistent significant deficits after a trial of conservative management (typically 6-12 months)
Indications include documented significant nerve injury (e.g., avulsion, neuroma) and failure to show functional improvement with intensive therapy
Procedures may include nerve grafting, nerve transfers, or neurolysis
Timing is critical, generally between 3-12 months of age, to maximize potential for axonal regeneration.
Supportive Care:
Regular follow-up with a multidisciplinary team including pediatric neurologists, orthopedic surgeons, physical therapists, and occupational therapists
Parents require education and support regarding the condition, treatment plan, and long-term outlook
Monitoring for signs of complications such as joint contractures or deformities.
Complications
Early Complications:
Joint contractures (e.g., shoulder adduction/internal rotation, elbow flexion, forearm pronation)
Pain
Swelling
Infection (rare).
Late Complications:
Permanent motor and sensory deficits
Muscle atrophy
Limb length discrepancy
Chronic pain
Osteoarthritis
Compensatory scoliosis
Psychological impact.
Prevention Strategies:
Minimizing birth trauma through careful obstetric management
Prompt recognition and initiation of conservative therapy
Timely referral for specialist evaluation and consideration of surgical intervention when indicated.
Prognosis
Factors Affecting Prognosis:
Severity of initial injury (e.g., avulsion vs
stretch)
Level of nerve involvement (upper vs
lower plexus, total)
Presence of associated injuries
Timeliness and intensity of rehabilitation
Age at intervention (if surgery is performed).
Outcomes:
Approximately 80-90% of infants with BPBI experience significant functional recovery with conservative management alone, especially with mild to moderate injuries
Complete recovery may take months to years
Significant residual deficits are more common in severe injuries or those requiring surgery.
Follow Up:
Lifelong follow-up may be necessary for individuals with significant residual deficits to monitor for long-term complications, manage pain, and adapt treatment strategies as the child grows
Regular orthopedic and neurological assessments are crucial.
Key Points
Exam Focus:
Differentiate Erb's, Klumpke's, and total BPBI
Recognize typical posture and muscle deficits
Understand the role and timing of physiotherapy and occupational therapy
Key surgical indications and timing (3-12 months)
EMG/NCS timing (3-6 weeks).
Clinical Pearls:
Always assess active and passive range of motion separately
Differentiate from clavicle fracture (tenderness over bone)
Early, consistent physiotherapy is paramount for function
Consider surgery only after a dedicated trial of conservative therapy.
Common Mistakes:
Delaying physiotherapy
Aggressive passive range of motion in the acute phase causing pain
Incorrectly attributing weakness to cerebral palsy without considering birth trauma
Inappropriate timing of surgical referral.