What causes inflammation in encephalitis?

Encephalitis is primarily characterized by inflammation of the brain, most commonly resulting from infections. Viral infections are frequently the culprits behind encephalitis, with pathogens such as herpes simplex virus, West Nile virus, and others being typical causes. The body’s immune response to these infections leads to inflammation as immune cells are activated to combat the invading pathogens, and this response, while necessary to eliminate the infection, can also contribute to the symptoms and damage observed in encephalitis.

In contrast, while vascular blockages, hypoxia, and toxic substances can lead to neurological problems, they do not specifically cause inflammation in the context of encephalitis. Vascular issues might lead to conditions like stroke, hypoxia might affect brain function due to lack of oxygen, and exposure to toxins could result in different forms of brain injury, but these do not directly cause the inflammatory process associated with encephalitis. Thus, the infectious nature of encephalitis is what solidifies infections as the correct answer to what initiates inflammation in this condition.