Abstract
Objectives: To ascertain the levels of trauma from an acceleration-deceleration event which would expose a person to brain trauma, and to suggest clinical guidelines to the evaluation of injury outcomes which would indicate significant brain trauma was a potential sequelae.
Methods: The brain-injury literature that related to clinical, psychological, biomechanical, and imaging studies was reviewed and compared for correlation to injury outcomes.
Results: The severity of cranio-cervical tissue damage is clearly correlated to the degree of acceleration-deceleration trauma exposure. The size of a brain lesion is in a direct correlation to the duration and depth of unconsciousness, and the duration of post-traumatic amnesia. The acceleration-deceleration mechanism of injury would expose the prefrontal, frontal, or temporal cortex to diffuse axonal injury. These brain regions are crucial for complex attentional functioning. Indicators of trauma severity [loss of consciousness] are correlated to both clinical [cognitive impairment] and neuro-imaging findings [PET]. Presumed head-neck trauma that leads to an unconscious period of less than 10 minutes, or an amnesia period that spans less than four hours [a minor concussion] is not likely to cause any lasting brain damage or dysfunctional mental sequelae based on brain trauma. If these relationships cannot be established, factors other than brain damage [pain, adverse effect of medication, alcohol, psychological-personality problems, other agendas] should be considered the basis of complaints following cranio-cervical acceleration-deceleration trauma.
Conclusions: Minor trauma exposure without a significant unconscious period, including amnesia, is very unlikely to have caused diffuse axonal injury, nor brain trauma.