Pathophysiology of Brain Injuries

A mild head trauma may result in cortical contusions resulting from coup or contrecoup injuries. Axonal fracture due to shear and tensile forces can happen during a severe head injury. There are moderate levels of axonal damage that can result in a milder traumatic brain injury (TBI). Interference of the axonal neurofilament system diminishes axonal transport leading to axonal swelling, Wallerian degeneration and transection. What may contribute to a minor injury is the release of excitatory neurotransmitters acetylcholine, glutamate, aspartate and a generation of free radicals.

There are a few theories pertaining to "blast or explosive traumas" such as the transference of kinetic energy through the vascular system, to the brain can lead to a traumatic brain injury (TBI) in the absence of a direct head injury. The proof is supported by those who have suffered a mild traumatic brain injury (TBI) and in animal illustrations of the brain injury. Evidence of microscopic axonal injury, axon reaction bulbs and microglial sets, have been described in pathological examinations of patients with minor head traumas, that died from other injuries. Dispersal tensor MRI studies of the corpus callosum in patients with mild TBI revealed increased limited anisotropy and diffusivity suggestive of a cytotoxic edema. In patients with mild head traumas, the neuroimaging studies have shown that certain patients may develop frequent and extensive areas of abnormality as ascertained by the SPECT, PET and MRI that is revealed on a CT scan. The findings have shown an individual more prone to becoming more psychologically unbalanced and may display signs of mild psychosis.

Clinical Characteristics

The characteristics of a concussion are confusion, amnesia, irritability, the lack of concentration while the patient is conscious. The signs of a concussion may be revealed immediately after the head trauma or a short time after. The characteristics of amnesia majority of the time, include memory loss pertaining to the traumatic event and the loss of memory pertaining to events before the and after the head injury occurred. Athletes who have suffered a head injury are a prime example of what can occur during and after a head trauma. The inability to recall the event that caused the head trauma is common. The individual is unaware of hisher environment, being unable to recall the intimate details of the game or being able to remember current events. Further evidence of amnesia after a head trauma is the patient repeating questions already answered and sometimes displaying certain phobias.

A person with amnesia may often display such signs, as confusion and loss of consciousness, which require crucial monitoring of the patient, in order to understand how a head trauma affects and injures the brain. Close monitoring of the patient after a head injury reveals important information about the severity of head traumas and the timeframe in which mild to severe brain damage can occur.

The signs of amnesia can evolve anywhere from moments after the injury occurred to hours or days after the brain injury. Early indications of a concussion are headaches, dizziness and lack of coordination, vertigo, being unaware of the surroundings, not recognizing family members or friends, nausea and vomiting. In some cases within days or hours of the injury patients may display mild to even severe mood swings complain of sensitivity to light and sound. The taste of certain foods and liquids are displeasurable and the head trauma victim may become hypersensitive to noise and may start experiencing sleep deprivation. The phenomena experienced during sleep may be horrific nightmares or even hallucinations while awake.

The signs of a person with a concussion are:

1. Blank stare-the lack of facial expression.
2. Delayed verbal response-the inability to respond questions or other stimuli quickly, such as verbal or written instructions.
3. Unable to focus or concentrate-the inability to concentrate or pay attention for periods of time. The person’s attention is shifting from one thing to another.
4. Disorientation-the lack of coordination when walking or doing other activities, not cognizant of time, days or places.
5. Slurred speech-displaying the inability to pronounce words and at times slurring one’s speech. The person may become easily distraught, agitated and may start to withdrawal from friends or family members.
6. Memory discrepancy-the individual’s memory is affected to the point that short-term or even long-term memory loss may become a temporary affliction or permanent. The loss of consciousness due for any period of time may also result in temporary too permanent memory loss.

In certain cases cortical neurological deficiency’s such a global amnesia or cortical blindness may occur.