Meningitis occurs when the lining of the brain and spinal cord (meninges) becomes inflamed. Cerebrospinal fluid (CSF), a clear fluid that surrounds and protects the brain and spinal cord, has an increased number of white blood cells. Aseptic meningitis occurs when there are signs of meningitis without an identifiable disease-causing agent.

Meningitis
Meningitis
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The most common causes of aseptic meningitis are: