Which condition involves inflammation of the meninges?

Meningitis is characterized by the inflammation of the meninges, which are the protective membranes that cover the brain and spinal cord. This inflammation can result from various causes, including viral infections, bacterial infections, or, less commonly, fungal infections. Symptoms often include headaches, fever, neck stiffness, and sensitivity to light, reflecting the body's response to the infection and irritation of the meninges.

In contrast, other conditions listed, such as arachnoiditis, cerebritis, and encephalitis, describe different pathologies. Arachnoiditis specifically refers to inflammation of the arachnoid membrane, one of the three layers of the meninges, but the term does not encompass inflammation of all meninges as a whole. Cerebritis describes the inflammation of the brain tissue itself, typically due to infection or injury, rather than the protective layers surrounding it. Encephalitis refers to inflammation of the brain, usually caused by a viral infection, rather than the membranes. Understanding the specifics of these conditions clarifies why meningitis is the correct answer, as it directly pertains to inflammation affecting all layers of the meninges.