DIFFUSE AXONAL INJURY (DAI)
A diffuse axonal is a traumatic brain injury in which lesions are produced in the white matter over a widespread area.
- Brain tissue is divided into cortical, or tissue found on the surface, and subcortical, or tissues found in the deeper part of the brain.
- White matter is a subcortical tissue, it is found in the deeper tissue of the brain.
- It is made up of the axon (nerve fibers) that are majorly surrounded by a covering or sheath called myelin.
- This myelin is white in color, which is why the myelin-covered axons are called white matter.
- The neurological impulses carried by the axons of white matter enable the body to function properly and are widespread within the brain.
- During the axonal injury, the axons that are damaged spread over a large area and not just one isolated spot, this is why diffuse is used with this type of injury
- Diffuse axonal injury mostly affects white matter in areas such as the brainstem, the corpus callosum, and the cerebral hemisphere. Other common locations include the white matter in the cerebral cortex, basal ganglia, and thalamus
- It is one of the most common and severe traumatic brain injuries as it affects numerous portion of the brain and is life-threatening.
- Most people who suffer severe injury are left in a coma and about 90% of patients never regain their consciousness.
- Those who do wake up are often left significantly impaired and even disabled.
- A person that suffers diffuse axonal injury may have mental and physical limitations and may often depend on others to perform basic tasks
CAUSES
A diffuse axonal injury is as a result of acceleration and deceleration that triggers the brain to move backward and forward swiftly inside the skull. This can occur due to:
- Car accidents or motorcycle accidents
- Falls especially those that cause rapid whipping motion of the head
- Violent attack
- Sporting injuries
- Shaken baby syndrome
SYMPTOMS
Patient with severe DAI may experience loss of consciousness. This is the prevailing symptom of the condition
In mild DAI, patient may have a concussive disorder associated with a headache, as well as:
- Loss of balance
- Drowsiness
- Disorientation or confusion
- Nausea and vomiting
DIAGNOSIS AND TREATMENT
DIAGNOSIS
Because damage to the brain is microscopic and not macroscopic, diagnosing DAI with CT scan may be difficult. However, a well-established MRI method called Diffusion Tensor Imaging is used. This procedure provides a detailed view of the brain and allows mapping of the orientation of the white matter tracts.
TREATMENT
Reducing any swelling in the brain is the first course of action needed in the case of DAI. If this is delayed, it can cause further damage
In some cases, steroids or anti-inflammatory drugs will be given to reduce the swelling
Severe traumatic injury has a likelihood of a vegetative state or death. In mild to moderate cases, rehabilitation is possible. Depending on the individual, recovery program can include:
- Speech therapy
- Counselling
- Adaptive equipment training
- Physical therapy
- Occupational therapy
- Recreational therapy
The traumatic brain recovery program involves a team of doctors, nurses, and specialists including physical, speech, occupational and recreational therapist.
Complete recovery may be possible in very mild cases