The signs and symptoms of encephalitis are the same for adults and children. Infants may have poor feeding, irritability, vomiting, bulging fontanel, and body stiffness; such symptoms in an infant always constitute a medical emergency.Signs and symptoms may last for two to three weeks, are flu-like, and can include one or more of the following which in some individuals may become progressively worse and continue over time:FeverFatigue, muscle weakness, rhythmic muscle contractions, muscle painSore throatStiff neck and backLoss of appetiteVomiting and nauseaHeadacheConfusionIrritabilityUnsteady gait, weaknessProblems with coordinationDrowsinessVisual sensitivity to lightMore severe cases may involve these signs and symptoms:SeizuresMuscle weaknessParalysisMemory lossSudden impaired judgmentDelirium and/or hallucinationsDisorientationPoor responsiveness or altered level of consciousness
