What is the primary etiology of Meningitis?

The primary etiology of meningitis is the inflammation and infection of the meninges, which are the protective membranes covering the brain and spinal cord. This condition can be caused by various pathogens, including viruses and bacteria, but it is fundamentally characterized by the inflammatory response in the meninges.

When an infectious agent invades the central nervous system, it leads to an immune response that results in the manifestation of symptoms associated with meningitis, such as headache, fever, and neck stiffness. In the case of bacterial meningitis, specific bacteria, like Neisseria meningitidis or Streptococcus pneumoniae, can be responsible, while viral meningitis is often caused by enteroviruses. Regardless of the specific causative agent, the hallmark of meningitis remains the inflammatory process affecting the meninges.

The other choices do represent related concepts in neurological conditions. For instance, viral infections of the brain can lead to encephalitis rather than directly causing meningitis, and autoimmune responses can lead to conditions affecting the brain but not specifically meningitis as it is defined by infection. A bacterial infection of the spinal cord is not an accurate description, as meningitis refers to the meninges surrounding the brain and spinal cord, rather than an infection specifically targeting the