Which agents most commonly cause meningitis?

Meningitis is primarily caused by infections, with bacterial and viral agents being the most common culprits. This reflects the pathophysiology of the condition, where pathogens invade the protective membranes covering the brain and spinal cord, leading to inflammation. Bacterial meningitis is usually more severe and can lead to serious complications if not treated promptly, often requiring antibiotics and close medical management. Viral meningitis tends to be less severe and may resolve on its own, often associated with common viruses like enteroviruses.

Other options, while relevant to different medical conditions, do not directly contribute to the primary causes of meningitis. For example, vitamin deficiencies may lead to neurological issues but are not known to directly cause meningitis. Autoimmune disorders can result in inflammatory conditions affecting the CNS, but they don't cause meningitis in the infectious sense. Likewise, head trauma can lead to various complications, including hemorrhagic strokes or infections, but it is not a direct cause of meningitis itself. Thus, the focus on bacterial and viral infections aligns with the understanding of meningitis etiology.