The cause of infection in this area is usually invasion by either bacteria or viruses.
Infection can reach the meninges in several ways.
It can be transported via the bloodstream from some other part of the body, such as the lungs or nasopharynx. It can also spread to the brain from an infected ear or sinus which is contiguous with the bones of the skull. An easy portal of entry would be a fractured skull with a meningeal tear. There are many types and degrees of severity of meningitis depending on the micro-organism involved and the immune status of the patient. If you or someone you know develops a combination of severe headache, stiff neck and photophobia, consult a physician immediately.