Guillain–Barré syndrome

Guillain–Barré syndrome
Name	Guillain–Barré syndrome
Synonyms	Acute inflammatory demyelinating polyneuropathy (AIDP), Landry's paralysis
Field	Neurology, Critical care medicine
Symptoms	Muscle weakness, areflexia, paresthesia
Complications	Respiratory failure, Autonomic dysfunction, Long-term disability
Onset	Rapid, often days to weeks
Duration	Variable; recovery can take months to years
Types	Acute inflammatory demyelinating polyneuropathy, Miller Fisher syndrome, Acute motor axonal neuropathy
Causes	Often triggered by Campylobacter jejuni infection, Zika virus, Influenza, COVID-19
Risks	Recent infection, Surgery, Vaccination (rarely)
Diagnosis	Based on symptoms, Lumbar puncture, Nerve conduction study
Differential	Myasthenia gravis, Botulism, Poliomyelitis, Heavy metal poisoning
Prevention	None
Treatment	Intravenous immunoglobulin, Plasmapheresis, Mechanical ventilation
Prognosis	Variable; most recover, mortality ~5%
Frequency	1–2 per 100,000 per year

Guillain–Barré syndrome is an acute, autoimmune disorder of the Peripheral nervous system characterized by rapid-onset muscle weakness. It is often triggered by a preceding infection, leading the Immune system to attack the Myelin sheath or Axon of Nerves. The condition can progress to Paralysis and Respiratory failure, requiring urgent critical care.

Signs and symptoms

The initial symptoms typically include Paresthesia in the feet or hands, followed by progressive Muscle weakness and Areflexia. Weakness often begins in the legs and ascends to the arms and Facial muscles. In severe cases, involvement of the Respiratory muscles leads to Respiratory failure, necessitating Mechanical ventilation. Autonomic dysfunction can manifest as Cardiac arrhythmia, Hypertension, or Ileus. Variants like Miller Fisher syndrome present with a distinct triad of Ophthalmoplegia, Ataxia, and areflexia.

Causes and pathophysiology

The syndrome is primarily an Autoimmune disease where the body's immune response mistakenly targets peripheral nerves. This is frequently preceded by an infection; common triggers include Campylobacter jejuni, Cytomegalovirus, Epstein–Barr virus, Zika virus, and Influenza. More recently, associations with COVID-19 and certain vaccinations (e.g., for swine flu) have been documented. The pathophysiology involves molecular mimicry, where antibodies against pathogens cross-react with components of nerve gangliosides, leading to inflammatory damage, Demyelination, or Axonal degeneration.

Diagnosis

Diagnosis is primarily clinical, based on the pattern of progressive weakness and areflexia. Key supportive investigations include Lumbar puncture, which typically reveals elevated CSF protein with a normal cell count (albuminocytological dissociation). Nerve conduction study and Electromyography help confirm the diagnosis and differentiate between demyelinating and axonal subtypes. Important conditions to rule out include Myasthenia gravis, Botulism, Poliomyelitis, and Heavy metal poisoning.

Treatment

The mainstays of treatment are Intravenous immunoglobulin and Plasmapheresis, which are equally effective in modulating the immune attack. These therapies should be initiated early in the disease course. Supportive care in an Intensive care unit is critical, with close monitoring for Respiratory failure and Autonomic dysfunction. Mechanical ventilation is required for approximately 25% of patients. Physical therapy and Occupational therapy are essential during the recovery phase to manage Long-term disability and improve functional outcomes.

Prognosis

The prognosis is variable; while most patients experience a good recovery, the course can be prolonged. About 80% of patients can walk independently at six months, but 20% may have significant residual Muscle weakness after a year. The mortality rate is approximately 5%, primarily due to complications like Pulmonary embolism, Sepsis, or Cardiac arrest. Poor prognostic factors include older age, rapid progression, need for ventilation, and evidence of Axonal degeneration on electrophysiological studies.

Epidemiology

The incidence is about 1 to 2 cases per 100,000 people annually worldwide, making it the most common cause of acute flaccid paralysis. It affects all age groups but incidence increases with age, and it is slightly more common in males. Epidemiological studies have shown geographical and temporal variations, with increased cases associated with outbreaks of Zika virus in French Polynesia and Latin America, and Campylobacter jejuni infections in China. Seasonal peaks may correlate with rates of antecedent infections.

Category:Autoimmune diseases Category:Neurological disorders