Abstract
Encephalitis is a major cause of morbidity, mortality, and permanent neurological disability in both adults and children. The term "encephalitis" literally means inflammation of part or all of the "brain" or the brain parenchyma. Encephalitis affects people of all ages; however, the incidence is higher in the pediatric population. Although both genders are affected, most studies showed slight dominance in men. There are two main types with different causes: primary or infectious encephalitis can develop when a fungus, virus, or bacteria infects the brain and accounts for approximately 70% of confirmed cases of encephalitis, and secondary or post-infectious encephalitis when the immune system is active and reacts. to a previous infection and mistakenly attacks the brain. The clinical manifestations depend on whether the brain parenchyma or the meninges are predominantly involved and cause an encephalitic or meningitis syndrome. Diagnostic tests should include a lumbar puncture, an MRI of the brain, and an EEG for suspected encephalitis. In encephalitis, a broad differential diagnosis, both infectious and non-infectious, should be considered. These alternatives include malignancy, autoimmune or paraneoplastic diseases (eg, anti-NMDA receptor encephalitis), brain abscess, drug-induced tuberculosis or delirium, neurosyphilis, or bacterial, fungal, protozoal, or helminthic encephalitis. Antiviral medications, such as intravenous acyclovir, are often given at the initial diagnosis of encephalitis before the cause is known. Acyclovir is the best treatment for herpes simplex encephalitis. If medication can be started soon after symptoms appear, the chance of a full recovery is much higher.