Infantile encephalitis has different pathogens and different early symptoms, as follows: 1. Viral encephalitis early manifests as fever, headache, vomiting, poorer spirit, gradually progressing to impaired consciousness, convulsions, coma, and the diagnosis of viral encephalitis can be clarified by cerebrospinal fluid testing and imaging tests. Because infants cannot complain of subjective symptoms, such as headache, clinical observation can be made to see if the fontanelle is elevated. If fever and bulging fontanelle are found, early manifestations of infantile encephalitis should be noted; 2. Bacterial meningitis infection symptoms are more severe and may include high fever, vomiting, poor mental health, bulging fontanelle, and in severe cases, convulsions and coma; 3. Tuberculous meningitis and central meningitis have a relatively slow onset and early symptoms are atypical. The early symptoms are atypical and may include low fever, decreased appetite, poor mental health and weight loss. As the disease progresses, severe neurological impairment gradually appears, including symptoms of cranial nerve involvement, such as convulsions, coma, and impaired consciousness.