Immune-Mediated Encephalopathy in the Setting of Legionnaires Disease: A Case Report and Review of the Literature

Abstract

Background: Legionnaires disease is the systemic manifestation of an infection by the gram-negative bacterium Legionella pneumophila. It most commonly presents with pneumonia, but can also cause extrapulmonary manifestations like cardiac, renal, gastrointestinal as well as neurologic symptoms like encephalopathy. It tends to occur in people who are elderly, immunocompromised and those with impaired respiratory (smokers) or cardiac (advanced heart failure) functions. The Legionella Urinary antigen is commonly used to diagnose Legionella infection. Almost half of the patients diagnosed with Legionnaires disease exhibit neurologic signs and symptoms. These neurologic abnormalities are usually not evident on neuroimaging, laboratory findings, and neuropathology.