guillain-barre syndrome

what is GBS?

family of immune mediated polyneuropathies occurring post infection

is GBS acute or chronic?

acute

is GBS an upper or lower motor neurone syndrome?

lower

is GBS an axonal or demyelinating polyneuropathy?

demyelinating

what is the main bacteria causing GBS?

campylobacter jejuni

what are the other possible causes of GBS?

- cytomegalovirus

- mycoplasma pneuomoniae

- EBV

- Zika

what is the clinical course of GBS?

4 weeks - history of gastroenteritis

symptoms start

2-4 weeks - peak of symptoms

months to years - recovery period

what is the pathophysiology of GBS?

molecular mimicry:

- infection triggers normal immune response - antibopdies

- antibodies match the myeline sheath proteins called gangliosides

- membrane attack complex forms on surface of Schwann cells

- macrophages target myelin = inflammatory demyelinating polyneuropathy

what is the most common form of GBS?

acute inflammatory demyelinating polyneuropathy (AIDP)

what are the clinical features of AIDP?

- symmetrical weakness and paraesthesia

- hyporeflexia of affected limbs

- progressive without intermittences

- ascending flaccid paralysis - beginning in lower extremeties

- dysautonomia

- cranial nerve involvement

- respiratory muscle weakness

- severe back pain common

what is does dysautonomia involve?

- diarrhoea/constipation

- brady/tachycardia

- urinary retention

what may be the signs of cranial nerve involvement?

- diplopia

- facial nerve palsy

- oropharyngeal weakness

what is the type of GBS that presents with descending paralysis?

Miller Fisher

what is the triad of Miller Fisher GBS?

- ophthalmoplegia (intially)

- ataxia

- areflexia

which antibodies are present in miller fisher GBS?

anti-GQ1B

what criteria is used to diagnose GBS?

Brighton criteria

what would be the results of a lumbar puncture in GBS?

- raised protein

- normal WCC

what would be the results of NCS in GBS?

abnormal

what sort of symptoms would be uncommon for GBS?

- asymmetry

- fever at onset

- hyperreflexia

what is the main mechanism of peripheral nerve damage?

autoimmune demylelination (a bit like MS)

what is the management of GBS?

IV immunoglobulins or plasma exchange

what is the key diagnostic test in GBS?

lumbar puncture - for raised protein and normal WCC

what is the best way to monitor for respiratory involvement?

forced vital capacity