Diffuse axonal injury, or termed as DAI, is typically observed in traumatic or closed head injuries. It is one of the most common but also fatal kinds of head injury. It’s a condition that is not easy to detect even through diagnostic imaging such as the CT Scan. Diffuse axonal injury may lead to unconsciousness, severe neurological damage and even death.
The movement of the brain within the cranium can result to diffuse axonal injury. Sustaining a closed head injury is a more complicated and severe case as compared to an open head injury because the brain tissues may sustain some tearing and inflammation may take place. The back and forth movement of the brain may interrupt the exchange of signals between the nerve cells. As a result, important nerve signal messages that facilitate and regulate the functions of speech, movement and vital signs may be disrupted and stopped.
Most commonly, diffuse axonal injury happens as a result of automobile accidents where the impact can cause sudden and forceful movement of the head and upper torso. It may also occur after a bomb explosion from an improvised explosive device (IED). Other incidents that may result to DAI may include falls, sports related injuries, baby shaken syndrome and abuse.
The number of patients suffering from a traumatic brain injury falls into the same category as the ones who are at risk of diffuse axonal injury. Most of the patients of DAI belong to young men.
Signs and symptoms
Unconsciousness is the most prominent sign of diffuse axonal injury. It may happen if the patient has been unconscious for more than 6 hours. A few numbers of cases stay conscious but have manifested other signs and symptoms that can be related to diffuse axonal injury. The state of consciousness depends on which parts of the brain were affected. The most important thing to do in case signs and symptoms of brain injury are observed is to seek professional medical attention. It is important that management is immediately provided to the patient to avoid further impairments.
Diffuse axonal injury appears as a characteristic distribution of multiple focal lesions along the junction of the white and grey matter, corpus callosum and, in some instances, on the brainstem. Although CT Scan imaging is a diagnostic procedure often done to patients with head injuries, it is not usually sensitive in detecting diffuse axonal injury. On the other hand, MRI is a good choice for diagnosis because it can assess possible DAI even if the CT Scan does not show it.
The management of any other types of brain injury is applied to diffuse axonal injury. The objective of care is to minimize the complications and impairment that the cerebral edema and hypoxia may cause to the body.
The condition of the patient may range from minimally affected to vegetative state. It depends on the location, distribution and severity of the brain injury. Unfortunately, diffuse axonal injury sustained on the brain stem may result to vegetative state. On the other hand, supratentorial injury may lead to neuropsychiatic and focal neurological impairments.