A 32-year-old man comes to the emergency department due to a 2-day history of progressive difficulty walking and tingling in his feet. He says that his feet feel "like they've gone to sleep" and states that he tripped while walking this morning. Medical history is unremarkable except for an episode of acute diarrhea 2 weeks ago that resolved spontaneously. The patient takes no medications. He drinks 1-2 alcoholic beverages daily and does not use tobacco products or illicit drugs. Vital signs are within normal limits. Physical examination shows decreased muscular strength in the lower extremities bilaterally with absent deep tendon reflexes. Which of the following agents is most likely associated with this patient's condition?
Guillain-Barré syndrome | |
Mechanism |
|
Triggering events |
|
Pathology |
|
Manifestations |
|
This patient with progressive lower extremity weakness, depressed deep tendon reflexes, and paresthesias has Guillain-Barré syndrome (GBS). GBS represents a group of immune-mediated demyelinating polyneuropathies that are thought to be caused by molecular mimicry. An antecedent event (typically an infection) provokes an immune response that cross-reacts with the Schwann cells and myelin sheath of the peripheral nerves. The myelin sheath is stripped from the axon, leading to loss of neuronal conductivity and axonal degeneration. Up to one-third of GBS cases are preceded by Campylobacter jejuni infection, a common cause of acute (sometimes bloody) diarrhea. Less common antecedent infections include upper respiratory viral illnesses, Epstein-Barr virus, cytomegalovirus, Zika virus, and HIV.
Patients with GBS experience symmetric, ascending weakness that typically begins in the legs and progresses to flaccid paralysis and respiratory failure. Decreased or absent deep tendon reflexes, paresthesias, pain (often of the back), and dysautonomia are common.
(Choices B, C, D, and E) Rotavirus, Salmonella, Shiga toxin–producing Escherichia coli, and Shigella are all important causes of diarrhea but are not associated with GBS. Both Shiga toxin–producing E coli and Shigella can cause bloody diarrhea and are associated with hemolytic uremic syndrome. Salmonella typically causes nonbloody diarrhea and may lead to bacteremia, particularly in an asplenic patient. Rotavirus, most commonly seen in children, causes nonbloody diarrhea and can lead to gastrointestinal obstruction due to small bowel intussusception.
(Choice F) Zika virus is associated with GBS; however, patients with Zika virus typically present with a pruritic maculopapular rash, low-grade fever, arthralgias, and conjunctivitis rather than diarrhea.
Educational objective:
Guillain-Barré syndrome represents a group of immune-mediated polyneuropathies that are thought to be caused by molecular mimicry, leading to demyelination of the peripheral nerves. Up to one-third of GBS cases are preceded by a Campylobacter jejuni infection, which is a common cause of acute diarrheal illness.