Meningeal syndrome can be caused by an inflammatory process. Caused by various microbial flora (meningitis, meningoencephalitis) or non-inflammatory lesions of the brain membranes. In these cases, the term "meningism" is used. In case of inflammation, the etiologic factor may be bacteria (bacterial meningitis), viruses (viral meningitis), fungi (fungal meningitis), protozoa (toxoplasmosis, amoeba).