Intracranial infection is commonly known as encephalitis or meningitis, infection caused by a number of causes, as follows: 1. In adults, the more common is tuberculous meningitis, both because bacteria invade the body and pass through the blood-brain barrier to the brain, causing bacterial inflammation; 3, and fungal, fungal meningitis more common is cryptococcal meningitis. Such patients are usually accompanied by low resistance, such as HIV infection, long-term use of immunosuppressants or use of hormones, are fungal meningitis; 4, there are other types of meningitis, such as syphilis spirochete infection caused by neurosyphilis, HIV infection caused by AIDS caused by meningitis, so the causes are more.