Guillian-Barre Syndrome

Question 1

What is GBS?

Answer 1

An acute inflammatory demyelinating ascending polyneuropathy

Question 2

Does GBS affect the peripheral or central nervous system?

Answer 2

Peripheral

Question 3

What cell type are attacked in GBS?

Answer 3

Schwann cells

Question 4

What is characteristic of the demyelination in GBS?

Answer 4

It is segmental and so happens in patches across the axon

Question 5

Briefly describe the pathophysiology of GBS?

Answer 5

1. Triggered by infection e.g. Campylobacter jejuni, EBV or cytomegalovirus (CMV)
2. Infection shares the same antibodies as those present on schwann cells e.g ganglioside
3. Autoantibody mediated nerve cell damage formation via molecular mimicry
4. Schwann cells destruction leads to segmental loss of myelin = disruption conduction of nerve impulse = polyneuropathy of the PNS

Question 6

What are the risk factors associated with GBS?

Answer 6

• History of respiratory or GI infections 1-3 weeks prior to onset
• Vaccinations have been implicated
• Post pregnancy - incidence decreases during pregnancy but increases in months after delivery

Question 7

What is the presentation of GBS?

Answer 7

• Loss of sensation
• Symmetrical ascending muscle weakness
• Pain is common
• Autonomic features such as sweating, raised pulse, BP changes, arrhythmias may be present
• There is a progressive phase of up to 4 weeks, followed by recovery

Question 8

Which muscles are more commonly affected in GBS?

Answer 8

Proximal muscles are more affected e.g. trunk, respiratory and cranial nerves (Especially CN7)

Question 9

What investigations would you be likely to do in GBS?

Answer 9

• Nerve conduction studies (NCS):
• Lumbar puncture - done at L4 (CSF has raised protein and normal white cell count)
• Spirometry

Question 10

What is the treatment for GBS?

Answer 10

• If FVC < 1.5L/80% then ventilate and admit to ITU-
• IV immunoglobulin for 5 days:
• Plasma exchange