Gliosis

Gliosis is a nonspecific reactive change of glial cells in response to damage to the central nervous system (CNS). In most cases, gliosis involves the proliferation or hypertrophy of several different types of glial cells, including astrocytes, microglia, and oligodendrocytes.

By strict definition, gliosis is not synonymous with encephalomalacia which is the end result of liquefactive necrosis of brain parenchyma following insult. Radiologically they share similar features and is often only of academic interest. Gliosis and encephalomalacia often coexist during the early and intermediate responses to injury, with gliosis waning with time.

asymptomatic serve as a focus of seizure Pathology

Glial cells constitute the non-neuronal component of the CNS, outnumbering the neurons 10:1, and are divided into two main groups: microglia and macroglia:

microglia

macroglia

astrocytes

oligodendrocytes

ependymal cells

Astrocytes and the microglia are the glial cells predominantly responsible for tissue response to injury. Astrocytosis involves the proliferation and hypertrophy of astrocytes, through complex molecular and cellular pathways. Microgliosis primarily occurs when the insult is infectious (particularly viral), as the microglial cells, which are not of neuroepithelial origin but are likely derived from monocyte or macrophage precursors, function in antigen presentation.