Non-Traumatic Brain Injury
Non-traumatic brain injury refers to any case where the brain is not injured using physical force, but rather via poisoning, tumor, infection or degenerative disease.
Causes of non-traumatic brain injury include lack of oxygen, which can be caused by stroke, heart attack, near-drowning, strangulation or diabetic coma. It can also be caused by infections like encephalitis (brain swelling), meningitis (meningeal swelling), cell toxicity, tumors, poisons, abuse or drug overdose, and degenerative conditions like Alzheimer’s Parkinson’s disease.
How the brain is injured
Degenerative conditions like multiple sclerosis or Alzheimer’s attack brain cells in various ways, not all of which are well understood. Unlike most traumatic brain injuries, where the damage is localized, most non-traumatic brain injuries (except tumors and local infections) are diffuse, with damage spread throughout the entire brain. In a non-traumatic injury, nerve cells may die from the direct action of a toxic substance or through being starved of oxygen, glucose or the blood which supplies both of those substances.
By taking up space, tumors may restrict blood supply to other cells or may, through exerting physical pressure upon cells, squash them. Infectious substances may cause cell death through exerting pressure if the brain swells (encephalitis) or the tissue surrounding the brain swells (meningitis), or may kill cells through direct infection. Viral infections may result in diffuse injury which can manifest as fatigue disorders like chronic fatigue syndrome.
In multiple sclerosis, nerve cells die when the fatty lining that protects them is removed. In diseases such as Alzheimer’s and Parkinson’s, there is a generalized or localized death of cells but the cause is not known or is very poorly understood.
Because of the diffuse nature of non-traumatic brain injury, diagnosis can be difficult. The small, scattered areas of damaged tissue typical of brain injury may not show up on a CAT scan. An MRI scan will usually show diffuse injury, but is not often used due to the increased cost.
Some cognitive abilities, particularly short term memory, are commonly affected. Fatigue is also extremely common, due to the brain having to work harder to work around diffuse areas of injury.
© 2015 BIC