Overview
Definition:
Guillain-Barré syndrome (GBS) is an acute, immune-mediated polyradiculoneuropathy characterized by rapid onset of ascending, symmetrical limb weakness and sensory disturbances
It is the most common cause of acute flaccid paralysis in developed countries.
Epidemiology:
Incidence varies from 0.5 to 2.0 per 100,000 person-years
In pediatrics, GBS is rare but represents a significant cause of acquired neurological disability
Bimodal age distribution, with peaks in young adulthood and older age groups, though it can occur at any age
Often follows an antecedent infection, commonly viral (e.g., enteroviruses, cytomegalovirus, Epstein-Barr virus) or bacterial (e.g., Campylobacter jejuni).
Clinical Significance:
GBS is a medical emergency requiring prompt diagnosis and management
Respiratory compromise can be life-threatening
Understanding the nuances of treatment options like IVIG and plasmapheresis is crucial for optimizing patient outcomes and preventing long-term sequelae in pediatric patients.
Clinical Presentation
Symptoms:
Progressive, ascending weakness, often starting in the legs and progressing upwards
Symmetrical involvement is typical
Sensory symptoms like paresthesias (tingling, numbness) are common, often preceding weakness
Pain, particularly in the back and limbs, can be severe
Cranial nerve involvement can manifest as dysphagia, dysarthria, and facial weakness
Autonomic dysfunction is also observed, including labile blood pressure, cardiac arrhythmias, and urinary retention.
Signs:
Decreased or absent deep tendon reflexes (areflexia or hyporeflexia) are a hallmark
Muscle strength is reduced, typically grading 0-3/5
Sensory examination may reveal diminished proprioception and vibration sensation
Bulbar weakness leading to impaired swallowing and speech
Respiratory muscle weakness necessitating mechanical ventilation
Autonomic disturbances may include tachycardia, bradycardia, hypertension, or hypotension.
Diagnostic Criteria:
American Academy of Neurology (AAN) guidelines for GBS diagnosis include: Progressive weakness in at least two limbs
Symmetrical weakness
Mild sensory symptoms or signs
Involvement of cranial nerves
Absence or reduction of deep tendon reflexes
Exclusion of other causes of acute paralysis.
Diagnostic Approach
History Taking:
Detailed history of recent infections (respiratory, gastrointestinal)
Onset and progression of weakness and sensory symptoms
Presence of pain
Any history of vaccination in the preceding weeks
Family history of neurological disorders
Autonomic symptoms
Functional impairment (e.g., difficulty walking, climbing stairs).
Physical Examination:
Comprehensive neurological examination focusing on motor strength (graded 0-5), sensation (light touch, pinprick, vibration, proprioception), reflexes (deep tendon and superficial), and cranial nerve function
Assess respiratory effort and tidal volume
Monitor heart rate and blood pressure for autonomic instability.
Investigations:
Cerebrospinal fluid (CSF) analysis: Lumbar puncture typically shows albuminocytologic dissociation (elevated protein with a normal cell count) after the first week of symptoms
Nerve conduction studies (NCS) and electromyography (EMG): Essential for confirming diagnosis and assessing severity
show demyelination (slowing of conduction velocities, prolonged distal latencies) and/or axonal damage
Pulmonary function tests (PFTs): To monitor respiratory muscle strength (e.g., vital capacity, negative inspiratory force).
Differential Diagnosis:
Other causes of acute flaccid paralysis: Transverse myelitis, polio and polio-like syndromes, botulism, spinal cord compression, myasthenia gravis crisis, tick paralysis, diphtheria, porphyria, organophosphate poisoning, toxic neuropathies, Miller Fisher syndrome (a variant of GBS).
Management
Initial Management:
Close monitoring in a hospital setting, preferably intensive care unit (ICU) if respiratory compromise is suspected or present
Airway protection and adequate ventilation are paramount
Early recognition and management of autonomic dysfunction
Pain management.
Treatment Options:
Two primary immunomodulatory treatments are proven effective: 1
Intravenous Immunoglobulin (IVIG): Typically administered as 0.4 g/kg/day for 5 consecutive days
This is generally preferred in pediatric practice due to ease of administration and lower risk of systemic complications compared to plasmapheresis
2
Plasmapheresis (Plasma Exchange): Involves removing plasma and replacing it with albumin or fresh frozen plasma
Usually performed as 4-6 exchanges over 7-14 days
It is generally used when IVIG is contraindicated or ineffective, or in severe cases where rapid improvement is desired
The choice between IVIG and plasmapheresis is based on availability, patient factors, and clinician preference, with IVIG being the favored initial treatment in pediatrics.
Supportive Care:
Respiratory support: Mechanical ventilation may be required for respiratory failure
Cardiovascular monitoring and management of autonomic instability: Fluid management, vasopressors, or antiarrhythmics
Prevention of complications: Deep vein thrombosis (DVT) prophylaxis (e.g., heparin), pressure sore prevention, bowel and bladder care
Nutritional support: Enteral or parenteral feeding if dysphagia is significant
Physical therapy: Early mobilization and rehabilitation to prevent contractures and muscle atrophy.
Complications
Early Complications:
Respiratory failure requiring mechanical ventilation
Autonomic instability (hypertension, hypotension, arrhythmias)
Cardiac arrest
Deep vein thrombosis (DVT) and pulmonary embolism (PE).
Late Complications:
Residual weakness and sensory deficits
Chronic pain
Fatigue
Psychological sequelae (anxiety, depression)
Post-GBS cerebellar ataxia
Pharyngeal dysfunction leading to aspiration pneumonia
Chronic respiratory insufficiency.
Prevention Strategies:
Aggressive supportive care to prevent respiratory and cardiovascular complications
Prophylaxis for DVT and pressure ulcers
Timely rehabilitation to minimize long-term motor deficits
Psychological support for patients and families.
Prognosis
Factors Affecting Prognosis:
Severity of initial weakness
Degree of respiratory involvement
Age (younger children generally have better outcomes)
Presence of antecedent infection (e.g., C
jejuni infection is associated with a worse prognosis)
Rapid onset and progression of symptoms
GBS variant (e.g., AMAN and AMSAN have different prognoses).
Outcomes:
Most children with GBS recover, though the recovery period can be prolonged (months to years)
Approximately 80-90% achieve a good recovery, with most returning to their pre-illness functional level
About 5-10% experience significant long-term disability, and a small percentage die, usually from complications of respiratory or autonomic failure.
Follow Up:
Regular follow-up is crucial to monitor recovery, manage residual deficits, address pain, and provide psychological support
This includes neurological assessments, physical therapy, and potential interventions for ongoing issues like fatigue or dysphagia.
Key Points
Exam Focus:
GBS is an immune-mediated demyelinating polyneuropathy
Ascending, symmetrical weakness with areflexia is characteristic
CSF shows albuminocytologic dissociation
IVIG is the preferred treatment in pediatrics, administered as 0.4 g/kg/day for 5 days
Plasmapheresis is an alternative
Respiratory failure and autonomic dysfunction are life-threatening complications.
Clinical Pearls:
Always consider GBS in a child with acute onset of flaccid paralysis
Prompt recognition of respiratory compromise is vital – monitor vital capacity closely
Autonomic instability can be unpredictable
have protocols ready
Pain management is critical for patient comfort and compliance with therapy
Early involvement of rehabilitation services is beneficial.
Common Mistakes:
Delaying diagnosis due to attributing weakness to other common pediatric illnesses
Underestimating the risk of respiratory failure
Inadequate monitoring of autonomic function
Failing to initiate immunomodulatory therapy promptly
Not considering GBS variants like Miller Fisher syndrome.