guillain barre syndrome

Question 1

definition

Answer 1

An inflammatory process where antibodies after a recent infection reacts with self-antigen on myelin or neurons. There are rare axonal variants with no demyelination. Often no aetiological trigger is identified (idiopathic in about 40%), in other cases:
. Post-infection (1–3 weeks): bacterial (e.g. Campylobacter jejuni ), HIV, herpes viruses (e.g. zoster, CMV).
. Malignancy (lymphoma, Hodgkin’s disease).
. Post-vaccination.

Question 2

signs and symptoms

Answer 2

Progressive symptoms of less than 1 month duration of:
. Ascending symmetrical limb weakness (lower > upper).
. Ascending paraesthesia.
Cranial nerve involvement (e.g. dysphagia, dysarthria and facial weakness). In severe cases, the respiratory muscles may be affected.
Miller–Fisher variant (rare): Opthalmoplegia, ataxia and arreflexia.

General motor examination: Hypotonia, flaccid paralysis, arreflexia (typ- ically ascending upwards from feet to head).
General sensory examination: Impairment of sensation in multiple modalities (typically ascending upwards from feet to head).
Cranial nerve palsies (less frequently): Facial nerve weakness (lower motor neurone pattern), abnormality of external ocular movements, signs of bulbar palsy. If pupil constriction is affected, consider botulism1.
Type II respiratory failure: Important to identify early (e.g. CO2 flap, bounding pulse, drowsiness). This can be insidious, and needs regular assessment.
Autonomic function: Assess for postural BP change and arrhythmias.

autonomic dysfunction can happen with GBS -> tachycardia/arrhythmias, BP fluctuations, urinary difficulties, constipation. –> make sure to have cardiac monitoring if these symptoms appear

Question 3

investigations

Answer 3

Lumbar puncture: increased CSF protein, cell count and glucose normal.
** CSF protein may be normal in early stages, but if clinical signs point to GBS start treatment.
Nerve conduction study: decreased Conduction velocity or conduction block, but can be normal in the
early phase of the disease.
Blood: Anti-ganglioside antibodies are positive in Miller–Fisher variant and 25% of Guillain–Barre syndrome cases; consider C. jejuni serology.
Spirometry: decreased Fixed vital capacity indicates ventilatory weakness.
ECG: Arrhythmias may develop.

Question 4

risk factors

Answer 4

• preceding viral infection (Two-thirds have a history of gastroenteritis or influenza-like illness)
• preceding bacterial infection (Campylobacter jejuni infection)
• hep E infection