Traumatic brain injury (TBI) is a prevalent, serious health problem with potentially long-lasting effects. Each year in the United States, 1.7 million people sustain a TBI that requires medical attention. Wars in the Middle East have led to more than 250,000 brain injuries among members of the military since 2000. Worldwide, TBI is the leading cause of chronic disability among young adults and children. Post-traumatic headache (PTH) is the most frequent symptom after a TBI.

In a recent study, Brett Theeler, MD, of the Walter Reed National Military Medical Center in Bethesda, MD, and his colleagues reviewed the scientific literature on PTH and evaluated several of its aspects in civilian and military populations. Their article appeared in the June 2013 issue of the journal Headache.

In civilians, the authors report that studies vary widely regarding how commonly PTH  occurs, with its prevalence ranging from 30% to 90%. Between 18 and 22% of the cases last longer than one year. Falls are the most common cause of TBI in children under 4 and seniors older than 75, but athletes at the college level and younger sustain 20% of the TBIs. Most often, symptoms resolve within one month, but in 10 to 20% of these cases, symptoms persist, particularly for athletes who have experienced repeated TBIs.

Males are more likely to develop PTH after a mild TBI than after a more severe injury, and females report the opposite, developing PTH after a moderate or severe TBI more often than after a mild injury. A prior history of headaches also increases the risk of developing PTH.

Among military members studied, PTH most frequently followed exposure to a blast, typically from an improvised explosive device (IED). Less than 20% of the service members who were evacuated because of PTH returned to active duty. Also significant among military members is that post-traumatic stress disorder (PTSD) is more likely to develop after a trauma that includes a TBI than other types of injuries, and PTSD can hinder effective treatment of PTH. Furthermore, migraine and headache are more common among soldiers who were deployed and involved in combat. For example, more than one-third of soldiers in one combat brigade reported migraine-like headache when they returned from deployment. The authors also found that positive psychological mood before being deployed guarded against both PTSD and PTH following a mild TBI.

In both civilians and military members, the authors found PTH could be classified according to primary headache disorder criteria, with migraine and probable migraine being the most frequent diagnoses. According to specific diagnostic criteria (ICHD-2), to be classified as a PTH, a headache must develop within 7 days of injury, but many cases develop outside that arbitrary limit, sometimes even 6 to 12 months after injury. The authors suggest that changes to the diagnostic criteria could bring more accurate diagnosis and treatment of PTH.

Given the frequency of PTH, Theeler and his colleagues recommend further study and an evidence-based approach to treatment. Until that time, they recommend that health care professionals treat PTH as they would the primary headache disorders of which PTH most closely resembles.