Influenza A (H1N1) pandemic vaccination -- an underlying risk factor for many CNS complications in Brazil.

The authors comment on the study "Neurological Complications After H1N1 Influenza Vaccination: Magnetic Resonance Imaging Findings" by R. Lessa and colleagues published in the journal in 2014. Topics discussed include environmental factors that have been considered triggers for immune destruction of central nervous system (CNS), the historical association between the influenza virus and narcolepsy, and vaccination against pandemic influenza H1N1 in Brazil.