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