American Board of Psychiatry and Neurology (ABPN) Practice Exam 2026 - Free ABPN Practice Questions and Study Guide

The association of Guillain-Barré syndrome (GBS) with certain pathogens has been well-documented, particularly with Campylobacter jejuni. This bacterium is a leading cause of gastroenteritis worldwide and has been identified as a significant trigger for GBS. The mechanism by which Campylobacter jejuni is linked to GBS involves molecular mimicry, where the immune response to the polysaccharides on the bacterial surface cross-reacts with nervous system components, leading to peripheral nerve damage.

Patients with GBS who have a history of Campylobacter jejuni infection tend to experience worse outcomes, such as more severe weakness and a prolonged recovery period. The illness can result from an autoimmune response triggered by the previous infection, which affects the myelin sheath of peripheral nerves.

In contrast, the other pathogens listed are not as strongly associated with Guillain-Barré syndrome in terms of incidence or severity. While infections like Haemophilus influenzae and Streptococcus pneumoniae can cause various illnesses, they have not shown the same direct link to GBS outcomes. Escherichia coli typically causes different forms of gastrointestinal illness and is not commonly associated with the syndrome. Therefore, the prominence of Campylobacter jejuni in the context of