How to Diagnose Guillain-Barré Syndrome
December 27, 2023
Written by Carmen Wolfe
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Is Guillain-Barre Syndrome (GBS) on your differential for neurologic symptoms? Let’s review this high morbidity/mortality disease.
Feeling “weak” about making this diagnosis? We got you!
Guillain-Barre Syndrome (GBS) is an immune-mediated disease affecting peripheral nerves. Molecular mimicry is the proposed etiology, with cases developing around 4-6 weeks after exposure to bacterial (C. jejuni, M. pneumonia, E. coli, H. influenzae) or viral infections (CMV, SARS-CoV-2, zika, EBV, etc), vaccinations, medications (immune-checkpoint inhibitors), or other stressors (surgery, pregnancy).
This diagnosis is frequently missed on initial presentation to the ED. The most common type of GBS is acute inflammatory demyelinating polyradiculopathy (AIDP), and classically presents with symmetric ascending weakness with decreased reflexes. However, GBS variants may look different – less than half of GBS patients have leg weakness on initial presentation. Keep a look out for combined motor/sensory symptoms (acute motor sensory axonal neuropathy), ophthalmoplegia/ataxia/areflexia with preserved strength (Miller-Fisher syndrome), ptosis/dysphagia/upper extremity weakness (cervico-brachial-pharyngeal variant) and acute orthostasis/urinary retention/ileus/ataxia (acute pseudodysautomonia).
GBS is a clinical diagnosis. ED evaluation should rule out GBS mimics. MRI may be needed to rule out central nervous system disease. The classic GBS diagnostic finding of CSF cytoalbuminologic dissociation (elevated protein with normal cells) may be absent early in the course of illness and isn’t reliable for definitive diagnosis.
Management in the ED starts with the ABCs. Make sure to check negative inspiratory force. Patients with bulbar dysfunction may require intubation for airway protection. Ascending paralysis can cause respiratory failure and necessitate mechanical ventilation. Succinylcholine is contraindicated in GBS due to increased risk of hyperkalemia in this population. Use only nondepolarizing neuromuscular blocking agents with either a lower dose or reversal agent after intubation. Most GBS patients require admission, neurology consultation, and treatment with IVIG or PLEX. Even with treatment, mortality is near 5% and up to 20% will be unable to ambulate independently one year from diagnosis.
How will this change my practice?
Since this diagnosis is frequently missed in primary ED encounters, I will increase my vigilance, especially in bounce back patients with motor, sensory, bulbar, or autonomic symptoms.
Source
High risk and low prevalence diseases: Guillain-Barré syndrome. Am J Emerg Med. 2023 Oct 28:75:90-97. doi: 10.1016/j.ajem.2023.10.036. Online ahead of print.