Guillain-Barré Syndrome

Question 1

Define Guillain-Barré syndrome

Answer 1

Guillain-Barre syndrome is an acute inflammatory polyneuropathy caused by peripheral demyelination

Question 2

Explain the aetiology / risk factors of Guillain-Barré syndrome

Answer 2

• GBS is characterised by an immune-mediated attack on the myelin sheath or Schwann cells of sensory and motor PERIPHERAL and CRANIAL nerves
• This is frequently triggered by an antecedent infection (not always)
• The infection is usually gastroenteritis or URTI - the most commonly identified infectious triggers include:
  
  • C jejuni (most common overall)
  • CMV (most common virus)
  • EBV
  • Mycoplasma pneumoniae
  • Vaccinations

RISK FACTORS:

• Preceding bacterial/viral infection
• Older age
• Male

Question 3

Recognise the presenting symptoms of Guillain-Barré syndrome

Answer 3

• Progressive SYMMETRICAL BILATERAL muscle weakness (ascending)
• SYMMETRICAL BILATERAL paraesthesia (ascending)
• Dyspnoea/SOB on exertion (severe cases need mechanical ventilation)
• DYSAUTONOMIA:
  
  • Urinary retention (cannot fully empty bladder)
  • Postural hypotension
• HEAD & NECK manifestations (not as common):
  
  • Dysarthria
  • Dysphagia
  • Facial droop
  • Extra-ocular muscle weakness/Diplopia

Question 4

Recognise the signs of Guillain-Barré syndrome on physical examination

Answer 4

• Hypotonia (flaccid)
• Hyporeflexia/Areflexia
• Postural hypotension
• Ascending loss of multiple sensory modalities
• Ileus
• Sinus tachycardia

Question 5

Identify appropriate investigations for Guillain-Barré syndrome and interpret the results

Answer 5

• Nerve conduction studies (reduced conduction velocity)
• Lumbar Puncture: elevated CSF albumin but normal cells due to inflammation of nerve roots (albuminocytologic dissociation)
• Spirometry: reduced vital capacity
• Antiganglioside antibodies

Question 6

Subtypes of GBS

Answer 6

Miller Fisher syndrome

variant of Guillain-Barre syndrome

associated with ophthalmoplegia, areflexia and ataxia. The eye muscles are typically affected first

usually presents as a descending paralysis rather than ascending as seen in other forms of Guillain-Barre syndrome

anti-GQ1b antibodies are present in 90% of cases

Question 7

Management

Answer 7

• plasma exchange
• IVIG (equally as effective as plasma exchange)
  
  • IVIG may be easier to administer and tends to have fewer side-effects
• Monitor respiratory function with FVC