Gliosis

Gliosis is a proliferation of astrocytes in damaged areas of the central nervous system (CNS). This proliferation usually leads to the formation of a glial scar.

Astrocytes are relatively large glial cells and have various functions, including accumulating in areas where neurons have been damaged. It is the most important histopathological sign of CNS injury. Astrocytes undergo both hypertrophy and hyperplasia. The nucleus enlarges and becomes vesicular and nucleolus becomes prominent. Previously scant cytoplasm expands and becomes bright pink or red and irregular from which arise numerous processes (gemistocytic astrocyte).

Bergmann gliosis is associated with anoxic injury and is characterized by death of Purkinje cells.

Gliosis and neuronal loss in certain brain regions are findings seen in various neurodegenerative disorders such as Alzheimer's disease, Korsakoff's syndrome, multiple system atrophy, prion disease, multiple sclerosis (after an acute attack) and AIDS dementia complex. It can also be found in Parkinson's disease, ALS and Huntington's disease.

It has also been associated with about 10% of patients with Celiac Disease or gluten-sensitivity (Archives of Neurology. 63(10):1440-6, 2006 Oct.). Gliosis damage to the brain in Celiac and gluten-sensitivity usually causes ataxia, peripheral neuropathy and/or cognitive impairment.

Gliosis is also a documented effect of neural infection by Transmissible Spongiform Encephalopathies (TSE). TSE's are better known as prion diseases, and are similar to Scrapie and Bovine Spongiform Encephalopathy (BSE or Mad Cow Disease). Prions are a specific sort of incorrectly folded protein.

See also

• astrogliosis
• glial scar
• astrocyte