Guillain-Barre Syndrome

Question 1

Definition

Answer 1

Acute inflammatory demyelinating polyneuropathy

Question 2

Aetiology

Answer 2

• An inflammatory process where antibodies after a recent infection react with self antigen on myelin or neurons
• There is often no aetiological trigger identified (40% of cases are idiopathic)

• Other causes:
o Post-infection (1-3 weeks) - bacterial, HIV, herpes viruses
o Malignancy - e.g. lymphoma
o Post-vaccination

Question 3

Epidemiology

Answer 3

• UK incidence: 1-2/100,000

* Affects all age groups

Question 4

Presenting symptoms

Answer 4

• PROGRESSIVE symptoms

• < 1 month duration of:
o ASCENDING symmetrical limb weakness (lower > upper)
o ASCENDING paraesthesia

• Cranial nerve involvement (leading to, for example, dysphagia, dysarthria, facial
weakness)

• Respiratory muscles may be affected in SEVERE cases
• Miller-Fisher Variant (RARE) = ophthalmoplegia, ataxia, arreflexia

Question 5

Signs on physical examination (motor and sensory)

Answer 5

• General MOTOR Examination
o Hypotonia
o Flaccid paralysis
o Arreflexia (ascending upwards from feet to head)

• General SENSORY Examination
o Impairment of sensation in multiple modalities (ascending from feet to head)

Question 6

Signs on physical examination (other)

Answer 6

• Cranial Nerve Palsies
o Facial nerve weakness
o Abnormality of external ocular movements
o If pupil constriction is affected, consider botulism

• Type II Respiratory Failure
o Due to paralysis of respiratory muscles

• Autonomic Function
o Assess postural blood pressure change and arrhythmias

Question 7

Investigations

Answer 7

• Lumbar Puncture
o HIGH protein
o NORMAL cell count and glucose

• Nerve Conduction Study
o Reduced conduction velocity
o NOTE: it may be normal in the early stages of the disease

• Bloods
o Anti-ganglioside antibodies in Miller-Fisher variant + 25% of Guillain-Barre cases

• Spirometry
o Reduced fixed vital capacity - suggests ventilatory weakness

• ECG
o Arrhythmias may develop