Learn all about Gliosis meaning, definition, symptoms, causes and treatment. Gliosis is NOT a disease or syndrome; it is a description of an area of scarring in the brain, perhaps secondary to prior trauma or disease.
Gliosis is a process of scarring in the central nervous system. It results from the proliferation of astrocytes in an injured or diseased part of the brain, causing the formation of a fibrous glial scar.
Although they are a necessary element to injury recovery, both the accumulation of glial cells and subsequent scarring are important markers of neurological damage. This scarring occurs after stroke, trauma, multiple sclerosis and Alzheimer’s disease, where it contributes to the total damage done to brain tissue by these conditions.
Gliosis is the universal response of the CNS to tissue injury and occurs as a result of many acute conditions such as trauma, ischemia, and stroke. In addition, gliosis is present in a wide variety of CNS pathologies, including Alzheimer’s disease, Korsakoff’s syndrome, multiple system atrophy, prion disease, multiple sclerosis, AIDS dementia complex, vasculitis, Parkinson’s disease, Amyotrophic Lateral Sclerosis, and Huntington’s disease.
Due to gliosis, brain weight and volume increase during the second year of life. Cystic degeneration of the cerebral white matter, along with atrophy of the cerebellar hemispheres, is frequently present. In the brain, neuronal number is diminished, and remaining neurons appear ballooned due to the stored material.
What is Gliosis
Gliosis (also known as reactive gliosis) consists of activation and proliferation of glial cells, stimulated by inflammatory cytokines including interleukin-1 (IL-1), tumour necrosis factor alpha (TNF-α) and interleukin-6 (IL-6). It is a combination of astrocytosis and microgliosis. Gliosis is not synonymous with encephalomalacia which is the end result of liquefactive necrosis of brain parenchyma following an 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.
Gliosis is a process of scarring in the central nervous system. Gliosis is the reactive response of the glial cells in the central nervous system following a trauma or injury to the brain.
Gliosis symptoms depend on the molecular and cellular changes of glial cells. The changes occur as part of a non-specific body response to damage and trauma that may occur in your central nervous system. The symptoms may occur in any area of the brain in which injury, trauma or disease has occurred.
Glial scars are largely created after glial cells collect all the dead or damaged neurons together. The scars will serve as barriers or walls to contain those dead or damaged neurons, in order to protect healthy cells surrounding the area from harm as a result of contact with dead or damaged cells. The clinical symptoms, then, depend on what part of the spinal cord or brain has been injured or damaged. They may occur in any area of the spinal cord or brain, especially where there has been an injury.
For example, gliosis found in your sensory cortex can cause you to experience a tingling sensation or numbness. If the gliosis is in the motor cortex, on the other hand, you may experience a sense of weakness. If your gliosis occurs in the occipital lobe, this may result in your experiencing impaired vision.
Gliosis occur after the astrocytes have proliferated. The incidence is brought by several factors that bring injury to the brain and the spinal cord. Injury, trauma and disease in the brain and the spinal cord trigger the process of gliosis. The migration macrophages and microglia to the site of the injury is the primary process of gliosis. This process in known as microgliosis which occur several hours immediately after the injury to the central nervous system has occurred. Over several days after microgliosis has developed, remyelination will occur after the oligodendrocyte precursor cells have migrated to the site of injury. The glial scar then develops after the surrounding astrocytes has proliferated or is known as astrogliosis.
Stroke or cardiovascular accident is a medical emergency in which the brain has ceased from functioning due to an interruption in the blood flow of the brain. The interruption to blood supply in any part of the brain may lead to death of brain cells. The interruption in the blood flow may occur in the brain and thus the process of gliosis.
Multiple sclerosis is an inflammatory disease of the nervous system that involves the myelin sheath of the nerve cells of the brain and the spinal cord. This inflammatory disrupts the communication between the brain and the rest of the body. The attack in the myelin sheath causes the damage in the brain tissue and the spinal cord which later will contribute to gliosis. Gliosis is the prominent feature of multiple sclerosis.
Other factors that contribute to gliosis include the following:
- Alzheimer’s disease
- Acute trauma in the central nervous system
- Amyotrophic lateral sclerosis
Gliosis treatment cannot be done since it is not an independent disease, but a consequence of a variety of pathological processes. Finding gliosis treat the cause to prevent the development of new foci of gliosis.
- Multiple therapies are presently in clinical trials for gliosis.
- Β-lactam antibiotics (e.g. Ceftriaxone) have been used to augment astroglial glutamate transport and thereby be anti-excitotoxic.
- Minocycline has also been used as suppressor of astrogliosis.
The cell cycle inhibitor olomoucine also has been shown to suppress microglial and astroglial proliferation as well as glial scar formation.