Delayed-Onset Neuropathological Complications From a Foramen Magnum and Occipital Crest-Focused Traumatic Brain Injury of the Vietnam War and Other Conflicts: Part II, Research Analysis

Introduction: Much of the research impacting diagnosis, outcome, and treatment of traumatic brain injuries (TBIs) has favored time of consciousness criteria indicative of hemispheric blast focus alone. However, recent animal-based research has widely expanded the diagnostic knowledge base and potential treatment options. Methods: Recent animal-based research findings of foramen magnum and occipital crest-focused blast injuries in laboratory rats were reviewed and compared to the Part I human case report. Results: Comparing the human case report (Part I) to that of animal research studies found very similar neuropathological outcomes, many deep and delayed, and supports why non-cerebral-focused TBIs have gone unrecognized. The overpressure wave is funneled through skull openings of the foramen magnum, with the possibility of a rebound secondary contrecoup injury impacting the orbits, oral-nasal cavity, and ears resulting in additional occult axonal and white matter injury. Conclusions: Research analysis prompted by a human case report (Part I) has helped identify mechanisms that assist in recognizing and defining non-cerebral hemispheric-focused TBI injuries. Position of the head in relationship to the blast wave, the setting in which the blast occurs, and close diagnostic follow-up are critical to the recognition, diagnosis, and treatment of injuries that have otherwise gone unrecognized and unstudied in humans since the Vietnam War.