Traumatic brain injury, shell shock, and posttraumatic stress disorder in the military--past, present, and future.

With preferential use of high explosives in modern warfare, traumatic brain injury (TBI) has become a common injury for troops. Most TBIs are classified as "mild," although military personnel with these injuries can have persistent symptoms such as headache, memory impairment, and behavioral changes. During World War I, soldiers in the trenches, undergoing unrelenting artillery bombardment, suffered from similar symptoms, designated at the time as "shell shock." Dr Frederick Mott proposed studying the brains of deceased soldiers to elucidate the neuropathology of this clinical entity. Subsequent to a British government enquiry after World War I, the term "shell shock" was banned and further investigation into a possible organic cause for these symptoms was discontinued. Nevertheless, similar clinical entities, such as combat or battle fatigue and posttraumatic stress disorder, continue to be encountered by combatants in subsequent military conflicts. To this day, there exists a paucity of neuropathology studies investigating the effects of high explosives on the human brain. By analogy, studies have recently revealed that athletes with repeated head trauma can develop a neurodegenerative disease, chronic traumatic encephalopathy, who present with similar clinical features. Given current circumstance, we propose completing the work envisioned by Dr Mott almost 100 years ago.