Overview
Definition
An acute, immune-mediated polyneuropathy characterized by rapidly progressive, symmetric weakness and absent reflexes.
Epidemiology
Rare (1-2 per 100,000), but the most common cause of acute flaccid paralysis worldwide.
Etiology & Risk Factors
- Post-infectious autoimmune response (molecular mimicry)
- Campylobacter jejuni (most common associated infection)
- Viral infections (CMV, EBV, Zika)
- Recent immunizations (very rare)
Clinical Symptoms
- Ascending, symmetric muscle weakness (starts in legs and moves upward)
- Areflexia (loss of deep tendon reflexes)
- Sensory symptoms (paresthesias, neuropathic pain)
- Autonomic dysfunction (tachycardia, blood pressure lability, urinary retention)
Clinical Approach
Diagnosis
- Clinical presentation
- Lumbar Puncture: Albuminocytologic dissociation (elevated CSF protein with normal/low WBC count)
- Electromyography/Nerve Conduction Studies (EMG/NCS): Demyelinating neuropathy pattern (slowed conduction velocities)
Management
- Intravenous Immunoglobulin (IVIG) OR Plasmapheresis (Plasma exchange) - equally effective, DO NOT give both
- Corticosteroids are INEFFECTIVE and contraindicated
- Frequent monitoring of Forced Vital Capacity (FVC) and Negative Inspiratory Force (NIF) to assess for impending respiratory failure
- Mechanical ventilation (required in ~30% of patients)
Complications
- Respiratory failure (involvement of the diaphragm)
- Autonomic instability (arrhythmias)
- Permanent residual weakness (in ~20% of cases)