Guillain-Barre Syndrome Flashcards
What is GBS?
immune-mediated demyelination of the peripheral nervous system often triggered by an infection
What infection classically triggers GBS?
Campylobacter jejuni
=> may be a history of gastroenteritis
Describe the pathogenesis of GBS
cross-reaction of antibodies with gangliosides in the peripheral nervous system
What antibody can be found in 25% of patients with GBS
anti-GM1 antibodies
Variant of Guillain-Barre syndrome
associated with ophthalmoplegia, areflexia and ataxia
Miller Fisher syndrome
Describe the pattern of disease onset in Miller Fisher syndrome compared to GBS
- eye muscles are typically affected first
- presents as a descending paralysis rather than ascending
Antibodies found in Miller Fisher syndrome
anti-GQ1b antibodies
Clinical features of GBS
- ascending weakness (legs first)
- reflexes reduced/absent
- sensory symptoms are mild (e.g. distal paraesthesia)
Less common features of GBS
- respiratory muscle weakness
- CN involvement (diplopia, facial nerve palsy, oropharyngeal weakness)
- urinary retention
- diarrhoea
Investigations
LP
nerve conduction studies
CSF findings in GBS
high protein
normal white blood cell count (albuminocytologic dissociation)
Nerve conduction study findings
- decreased motor nerve conduction velocity (due to demyelination)
- prolonged distal motor latency
- increased F wave latency
Management of GBS
IV immunoglobulins (IVIG) or plasma exchange
FVC regularly to monitor respiratory function
Poor prognostic features
- age > 40 years
- poor upper extremity muscle strength
- Hx of a diarrhoeal illness (specifically Campylobacter)
- high anti-GM1 antibody titre
- need for ventilatory support