[Encephalitis caused by type B influenza virus in an adult. Report of one case].

Neurological manifestations associated with influenza virus infection include encephalitis, encephalopathy, acute necrotizing encephalitis, transverse myelitis, acute disseminated encephalomyelitis, mild encephalitis with reversible splenial syndrome (MERS), and Guillaín Barré syndrome. We report a 16-year-old female who was admitted at our emergency department with seizures, confusion, nystagmus and motor clumsiness five days after an upper a respiratory tract infection. Influenza type B virus infection was confirmed by chain polymerase reaction analysis. The initial electroencephalogram demonstrated a pattern of global slowness without epileptic discharges. One week later, it showed a progression to slow-wave focal bilateral discharges at both temporal and occipital lobes. The patient had a favorable evolution and was discharged 19 days after admission with phenytoin to prevent seizures.