Non Traumatic Brain Injury
Any injury to the brain that does not result from any cause that does not injure the brain using physical force, but rather occurs via poising, tumor, infection or degenerative disease.
Causes include lack of oxygen, glucose, or blood are considered non-traumatic. Infections can cause encephalitis (brain swelling), meningitis (meningeal swelling), or cell toxicity, as can tumors or poisons. These infections can occur through stroke, heart attack, near-drowning, strangulation or a diabetic coma, poisoning or other chemical causes such as alcohol abuse or drug overdose, infections or tumors and degenerative conditions such as Alzheimer’s disease and Parkinson’s disease.
How the brain is injured
Degenerative conditions, such as Multiple Sclerosis or Alzheimer’s disease 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 calls 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.
Tumors, by taking up space, 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 such as chronic fatigue syndrome.
There are several mechanisms which may be at work with degenerative conditions. In multiple sclerosis, nerve cells die when the fatty lining which protects them is removed.
In many diseases such as Alzheimer’s and Parkinson’s, there is a generalised or localised death of cells but the cause is not known, or is very poorly understood.
Differences between traumatic and non-traumatic injury
In a traumatic injury, damage to nerve tissue is usually focused in one or more areas of the brain, although tearing can result in diffuse injury.
With a non-traumatic injury, damage is usually spread throughout the brain. Exceptions to this include tumors and an infection that remains localised or spreads evenly from one starting point.
This can make diagnosis difficult because small, scattered areas of damaged tissue may not show up on a CAT scan. An MRI scan will usually show diffuse injury but is not often used due to the high cost of the scan.
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.
© 2008 BIC