GBS

Question 1

definition of GBS

Answer 1

acute inflammatory demyelinating polyneuropathy

Question 2

varients of GBS

Answer 2

chronic inflammatory demyelinating polyradiculopathy - slower onset and recovery

miller fisher syndrome - compromises of ophthalmoplegia, ataxia, areflexia. Associated with anti-GQ1b Ab in the serum

Question 3

aetiology of GBS

Answer 3

an inflammatory process where Ab after a recent infection reacts with self-ag on myelin or neurons

rare axial variants with no demyelination

idiopathic - 40% cases

Post-infection (1–3 weeks): bacterial (e.g.Campylobacter jejuni, mycoplasma), HIV, herpes viruses (e.g.zoster, CMV,), EBV

malignancy - lymphoma, hodgkin’s disease

post-vaccination

may advance quickly affecting all limbs at once - can lead to paralysis

progressive phase of up to 4wks, followed by recovery

Question 4

epidemiology of GBS

Answer 4

Annual UK incidence is 1–2 in 100000

all age groups

Question 5

sx of GBS

Answer 5

progressive symptoms for <1mo: ascending symmetrical limb weakness (lower>upper), ascending parasthesia

CN involvement - dysphagia, dysarthria, facial weakness

in severe cases the resp muscles may be affected

Miller–Fisher variant (rare): Opthalmoplegia, ataxia and arreflexia.

proximal muscles involved - trunk, resp, CN especially CN7

Question 6

signs of GBS

Answer 6

a few weeks after infection a symettrical ascending muscle weakness starts

proximal muscles more affected

can lead to paralysis

general motor examination

• hypotonia
• flaccid paralysis
• arreflexia - typically ascending upward from feet to head

general sensory exam - impairment of sensation in multiple modalities - typically from feet to head

CN palsy

• less frequent
• facial nerve weakness (lower motor neuron pattern)
• abnormality of external ocular movements
• signs of bulbar palsy
• if pupil constriction affected - consider botulism

T2 resp failure

• identify early - CO2 flap, bounding pulse, drowsiness
• can be insidious - needs regular assessment

autonomic function

• assess for postural BP change and arrhythmias
• sweating
• high pulse

pain common - back and limb

Question 7

botulism

Answer 7

caused by botulinum toxin by Clostridiuym botulinium anaerobe

typically ingested from improperly cooked meat, can be iatrogenic eg Botox IM or via wounds

presents: descending paralysis affecting bulbar and ocular muscles 1st = bilateral fixed pupils

treatment - supportive airway managment and antitoxin - doesnt reverse the weakness

Question 8

Ix for GBS

Answer 8

LP

• high CSF protein
• cell count and glucose normal

nerve conduction study - reduced conduction velocity or conduction block, can be normal in early phase of the disease

blood

• anti-ganglioside Ab +ve in Miller-Fisher variant and 25% of Gillain Barre syndrome cases
• consider C jejuni serology

spirometry

• reduced fixed vital capacity - indicates ventilatory weakness
• do FVC every 4hr

ECG - arrhythmias

Question 9

mx of gbs

Answer 9

IVIG or plasma exchange

measure FVC regularly