Guillain Barré Flashcards
What is Guillain Barré?
Rapid onset muscle weakness caused by the immune system damaging the PNS
AKA acute inflammatory demyelinating polyneuropathy
Key points about Guillain Barre
- Bilateral (usually)
- Demyelination of PNS
- Starts with tingling + weakness in hands + feet - spreads
- Develops over hrs-weeks
- 15% develop weakness of resp. muscles: need ventilation
*Very uncommon to get bladder dysfunction*
Do patients with Guillain Barre lose control over bladder?
No - very rare
Risk factors for Guillain Barre
Classic is a hx of GI/ resp. infection 1-3 weeks prior
Campylobacter enterocolitis = most commonly associated disease
Pathophysiology of Guillain Barre
- T-cells produce cytokines that activate B-cells which make antibodies against myelin
Connection between neurones breaks down = sensory, motor and cognitive dysfunction
75% of patients have a preceding infection - molecular mimicry occurs where body attacks neurones thinking they are the bacteria
- Deymelination occurs in patches (segmental demyelination)
Which nerves are demyelinated as a result of Guillain Barre?
PNS nerves and CN III-XII
Line to describe Guillain Barre
Post infectious autoimmune polyneuropathy causing patchy demyelination in the PNS and cranial nerves
What are the initial symptoms of Guillain Barre?
Pins + needles, pain, weakness in extremities
‘Started wiht a tingling sensation in legs and now cannot lift them’
Double vision
Classical presentation of Guillain Barre
Bilateral flaccid paralysis spreading from the legs to the arms in a stocking-glove distribution
Weakness, tingling, double vision over a few days
Weakness in hands
Symmetrical/ bilateral
Patients go from being active and independent to bedbound within days-weeks
What does the presentation of Guillain Barre depend on?
Nerves affected
Motor: muscle weakness, absent reflexes (ankle reflex lost 1st - LMN sign)
Cranial nerves: double vision, facial diplegia
Phrenic nerve: respiratory failure as diaphragm paralysed
Autonomic nerves: bowel and bladder symptoms, constipation, incontinence
What would happen to reflexes in Guillain Barre?
They would reduce because it affects PNS and is therefore a LMN lesion
Autonomic symptoms associated with Guillain Barre
Arrhythmias, HTN or low BP
Intestinal dysfunction
Reduced sweating
Reduced heat tolerance
Investigations for Guillain Barre
Lumbar puncture: Acellular CSF + high protein (albumin) *WBC should be normal, anything >50/uL means GBS unlikely*
Nerve cnduction: widespread slowed conduction (can be normal early on)
Resp. function tests
- Antibody screen: antibodies against peripheral nerves
ECG: lack of HR variation related to breathing - breathing in should cause HR to increase, breathing out should cause it to decrease
Examination findings in Guillain Barre
- Hypotonia
- Hyporeflexia
- Facial weakness
- Fluctuations in HR and BP
- Respiratory muscle weakness/ paralysis
Management of Guillain Barre
Can be life threatening: admit and monitor closely
Supportive: monitor breathing, HR, BP
- IV immunoglobulin = 1st line
- Plasma exchange to remove the antibodies damaging myelin
- DVT prophylaxis
- Pain relief for neuropathic pain
**Do not give corticosteroids - may delay recovery**