Last Updated: March 27, 2020
Abscesses begin as focal areas of infected brain called cerebritis, which may result from direct spread (commonly iatrogenic or from mastoiditis, sinusitis, or meningitis) or from hematogenous spread. There are four characteristic zones of an abscess that include a cavity of central necrosis, a capsule composed of fibroblasts, reticulin and collagen, peripheral edema, and areas of extraparenchymal spread (meninges, ventricles, CSF spaces, bone, blood vessels).
There are 4 stages of brain infection between cerebritis and abscess, which are as follows:
- Early cerebritis
- Late cerebritis
- Early capsule
- Late capsule
The lesions are either located near extra-axial infection or at common sites of hematogenous spread that are usually supratentorial, usually in the anterior circulation (ACA and MCA), and usually at the grey-white matter junctions and basal ganglia.
The most distinguishing characteristics of abscesses are peripheral enhancement around a cavity of central necrosis and pus. Without further information, however, the finding of solitary or multiple ring-enhancing lesions i...