Meningitis and Encephalitis: What’s the Difference?

“Meningitis” and “encephalitis” are two words that pop onto most people’s radar screens from time to time, and usually in some scary context, like hearing of a cluster of cases in their child’s school, or reading media reports of epidemics occurring nationally or internationally. While most people understand that these words mean there is some sort of infection of the nervous system, other distinctions and implications are often left unstated and, as a result, can be vague or confusing.

The basic concepts are built into the words themselves. Starting at the ends of the words and working forwards, “-itis” is the medical suffix meaning inflammation. Although it’s possible for inflammation to occur without an infection being present, as a practical matter, in most cases of meningitis or encephalitis the inflammation is indeed due to an infection.

The next step in understanding these concepts is to analyze the first parts of the words. “Mening-” refers to the meninges which are the membranous coverings of the brain and spinal cord. So “meningitis” means inflammation or infection of these...