SEARCH RESULTS FOR: Guillain-Barre-Syndrome

Guillain-Barre Syndrome

Guillain-Barré Syndrome: Pathogenesis and clinical findings Author: Nissi Wei Mao Ding Reviewers: Owen Stechishin Matthew Harding Cory Toth* * MD at time of publication ↑ Protein in cerebrospinal fluid (CSF) Minor triggers surgery, trauma, bone marrow transplant Initiate immune response (unknown mechanism) GI/respiratory infection (1-3 weeks prior) Campylobacter jejuni, cytomegalovirus, HIV, Epstein-Barr Virus Molecular mimicry: shared ganglioside antigens between peripheral nerve and pathogen coat proteins IgG antibodies to ganglioside antibodies in serum Nerve Conduction Study : ↓ conduction velocity, conduction block Triggered immune response cross-reacts with peripheral nerves, beginning at nerve roots ↑ permeability of blood- nerve barrier at level of proximal nerve roots Demyelination: antibodies attack Schwann cells secondary damage Axonal damage: antibodies attack nodes of Ranvier Nerve Conduction Study: ↓ CMAP (compound muscle action potential) amplitude, normal conduction velocity Acute inflammatory demyelinating polyneuropathy (AIDP) (80-90%) Acute motor axonal neuropathy (AMAN) Acute motor sensory axonal neuropathy (AMSAN) Acute immune-mediated polyneuropathy Tachycardia & Dysrhythmias (Needs cardiac monitoring) Sudden Death Dysautonomia: disruption of the autonomic nervous system responsible for involuntary functions Sensory deficits Motor deficits Universal Areflexia (loss of deep tendon reflexes) Phrenic nerve involvement Diaphragm paralysis Cranial Nerve (CN) involvement Bulbar palsy (CN IX, X, XI,XII) Oculomotor weakness (CN III, IV, VI) Eye Movement Abnormalities (Miller Fisher Syndrome – rare form of regionally- restricted AIDP) BP Fluctuation/ Orthostatic Hypotension (drop of blood pressure from seated/lying to standing) Urinary Retention (transient, late-course) Limb Weakness (legs usually affected first) Impaired swallowing àaspiration pneumonia ↓ ability to clear airway secretions Pain & Paresthesia (in back and extremities) Respiratory Failure (Life threatening: needs ventilatory observation and possibly support) Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published Nov 1, 2013, updated Oct 15, 2023 on www.thecalgaryguide.com Guillain-Barré Syndrome Minor triggers (surgery, trauma, GI/respiratory infection Campylobacter jejuni, CMV, HIV , EBV (1-3 weeks prior) Molecular mimicry: shared ganglioside antigens between peripheral nerve and pathogen coat proteins Author: Nissi Wei Reviewers: Owen Stechishin Matthew Harding Cory Toth* * MD at time of publication ↑ Protein in CSF bone marrow transplant) Initiate immune response (unknown mechanism) IgG antibodies to ganglioside antibodies in serum NCS: ↓ conduction velocity, conduction block Triggered immune response cross-reacts with peripheral nerves, beginning at nerve roots ↑ permeability of blood- nerve barrier at level of proximal nerve roots NCS: ↓ CMAP amplitude, normal conduction velocity Demyelination: antibodies attack Schwann cells secondary damage Axonal damage: antibodies attack nodes of Ranvier Acute inflammatory demyelinating polyneuropathy (AIDP) (80-90%) Acute motor axonal neuropathy (AMAN) Cranial nerve involvement Dysautonomia Acute motor sensory axonal neuropathy (AMSAN) Eye Movement Abnormalities (Miller Fisher Syndrome – rare form of regionally-restricted AIDP) Acute immune-mediated polyneuropathy Oculomotor weakness (CN III, IV, VI) Bulbar palsy (CN IX, X, XI,XII) Phrenic nerve involvement ↓ ability to clear airway secretions Impaired swallowingà aspiration pneumonia Diaphragm paralysis Respiratory Failure (Life threatening: needs ventilatory observation and possibly support) Motor deficits Sensory deficits Pain & Paresthesias in back and extremities Limb Weakness (legs usually affected first) Universal Areflexia Urinary Retention (transient, late-course) Sudden Death BP Fluctuation, Orthostatic Hypotension Tachycardia, Dysrhythmias (Needs cardiac monitoring) Abbreviations: • NCS - nerve conduction study • CMAP - compound muscle action potential • EBV - Epstein-Barr Virus • CMV - cytomegalovirus • CN - cranial nerve Note: Aα, Aβ peripheral nerve fibres (large, fast-conducting, heavily myelinated axons for muscle stretch, light touch & proprioception) are more affected than Aδ and C fibres (small, less myelinated, slowly-conducting fibres for pain and temperature) Legend: Pathophysiology Mechanism Sign/Symptom/Lab Finding Complications Published November 1, 2013 on www.thecalgaryguide.com