Typically caused by a bacterial infection or fungal infection, a brain abscess is a pool of pus, immune cells or other materials in the brain.
Brain abscesses usually occur when bacteria, fungi, infected brain cells or white blood cells infect part of the brain, and swelling and irritation (inflammation) result. Tissue forms around these cells and creates a mass, known as an abscess.
Germs cause brain abscesses. They can reach the brain in multiple ways:
Enter the brain directly, during brain surgery
From a sinus infection (rare)
Through the blood from another infection, such as in the lung or heart
A child with a brain abscess may show symptoms right away, or they may come on more gradually.