We report the case of a 35-year-old woman who developed headache and p
sychosis and gradually became comatose within 3 weeks after a flu-like
infection. MRI revealed bifrontal demyelination consistent with acute
disseminating encephalomyelitis (ADEM). Two different cerebrospinal f
luid samples were positively tested for Legionella cincinnatiensis by
direct sequencing of a PCR-amplified Legionella-specific fragment, Thi
s result made it possible to interpret the initial symptoms as Pontiac
fever. We think it most likely that this is a case of ADEM following
the very rare situation of a systemic infection with L. cincinnatiensi
s, A review of the literature on Legionella-associated encephalopathy
suggests that some of these cases may also have had ADEM.