Abstract and Introduction
Introduction
The roads into and out of military towns are straighter and wider than the traveler might think is necessary. Civilian and military traffic bear heavy loads to and from the bases. For the last 2 years, once per week I have left behind the narrow and less straight roads of the academic and private practice of Headache Medicine in Chapel Hill to treat injured soldiers at the Traumatic Brain Injury (TBI) Center of Womack Army Medical Center, Ft. Bragg, NC.
In Army Regional Medical Centers (ARMCs) like ours, healthcare providers attend Soldier Readiness Centers (SRCs) where returning servicemen and women are processed back into the fabric of the working community on base. Across the country, hundreds of soldiers come through these starkly furnished facilities, filling forms and taking tests. Here is where, on redeployment surveys of many types, the important information necessary to understand the injuries of war are being gathered.
Charles Hoge, MD, has described the broad range of symptoms which soldiers experience after mild traumatic brain injury (mTBI). Using redeployment surveys, he attempts to untangle mTBI from post-traumatic stress disorder (PTSD). In the first study published about this population (Hoge CW, McGurk D, Thomas JL, Cox AL, Engel CC, Castro CA. Mild traumatic brain injury in U.S. soldiers returning from Iraq. N Engl J Med. 2008;358(5):453–463), he concluded that headache was among those symptoms which could not be statistically ascribed to PTSD and was more likely attributable to head injury. His most recent paper (Wilk JE, Thomas JL, McGurk DM, Riviere LA, Castro CA, Hoge CW. Mild traumatic brain injury (concussion) during combat: lack of association of blast mechanism with persistent post-concussive symptoms. J Head Trauma Rehabil. 2010;25(1):9–14) looks more closely at those symptoms that separate explosive blast injuries from non-blast related mTBI. The 2 symptoms that segregate blast from other injuries are tinnitus and headache. He ascribes tinnitus to the well established damage that waves of overpressure generated by blasts cause to aural structures including the tympanic membrane. He ascribes headache to whiplash or other mechanical forces. The findings in the current article in Headache argue for a much more sophisticated approach.
Migraine-type headache is being acquired in people not usually prone to it, especially males without personal or family histories. Whether there is permanence to the changes in brain structure after repeated blasts will determine if a whole population of war veterans looks forward to living with disabling and refractory headache. Treatments, as the current article suggests, may be effective. Yet the science of treatment is still in its infancy.
In this issue of Headache, CPT Brett Theeler, MD, takes us into the world of mTBI in soldiers returning from our 2 wars where important questions about the nature and type of post-concussive symptoms persist. These same questions are now being asked by professional athletic associations studying sports concussion. Academic research groups are eager to study cognitive, somatic, and psychological outcomes in sports, motor vehicle, and military concussion. Yet headache, still considered among the most disabling and refractory symptoms, remains poorly understood. The assumption that we should link primary headache phenomenology to secondary headaches for treatment is a long standing dogma. The meaning of headache after mTBI will only be known after large scale studies of homogenous populations are completed. The experiences of soldiers engaged in the wars in Iraq and Afghanistan are now providing some of this evidence. CPT Theeler's paper adds important clues to our search for reliable evidence. Ultimately, studies such as this will lead to effective treatments.
First among the author's findings is the utility of the methodology. Soldiers who return are met with a program of reintegration and health assessment that is completed within 72 hours. These hectic days are also the time when many are eager to get necessary rest and family time. Because of this, the reliability of the information that we get is expectedly imperfect. Nevertheless, the authors appear to have adequately addressed this possibility and their data reflect my personal experience of SRCs and at our TBI Center.
In addition, this paper demonstrates a way of capturing information about headache type. Assuming a higher than normal prevalence of headache in male soldiers, there is still the question of new headache versus the worsening of primary headache. That essentially all soldiers with operationally defined concussion have headaches is staggering evidence of "state," eg, circumstance. Assuming normal biology, this cohort is unique: "(W)hen considering the incidence of migraine in an American male under the age of 20 is 0.021% per month; the chance occurrence of a primary headache disorder such as migraine within 4 weeks or even several months of a concussion is unlikely," state the authors. How true this is; and using their own statistics, a simple calculation could show that 2% of all screened soldiers have chronic daily headache (my emphasis). The Ft. Bragg experience of other acquired primary headaches after injury is also staggering. Of 14 patients with blast injury presented in our poster at the International Headache Congress last fall, there are 2 cases of cluster-type headache, other trigeminal autonomic cephalalgias and, most remarkably, new onset migraine with aura. The additional finding of nearly universal continuous headache tempers Dr. Theeler's finding of "more than 15 days" in a month.
Later onset post-traumatic headache happens. It appears to occur for many reasons. Concurrent spine, arm, and leg injuries demand immediate attention and may distract from the more mild headache symptoms during the first week or two. The immediacy of injury and loss of comrades may make headache a less pressing symptom. Return to duty, that being the highest priority may make minimizing an acceptable strategy for dealing with headache. Yet the findings in those with onset in a month confirm more headache days, sick calls, and use of medication. As CPT Theeler points out, that subset of soldiers who require neurology clinic or TBI Center evaluations do have high levels of headache related disability.
Another challenge that this article poses is whether time alone results in "healing" proximate to the injury, ie, that most injuries will get better in a short time. The Department of Defense has responded to this challenge by toughening guidelines for evaluations in the first 72 hours after injury. Repeated injuries appear to cause more long-lasting damage. Though this is not specifically addressed in the current paper, nor is the type of injury, we should be grateful for this addition to our knowledge. Using these data, one could estimate that 50,000 (3.4% of the greater than 1.5 million who have rotated through the wars) soldiers will return to home with chronic daily headache due to mild concussion. And among them, many will have continuous headache and some will be severely disabled. The addition of PTSD and the other consequences of injury add to their suffering.
The American Headache Society (AHS) has become a leader in the loosely coordinated effort to meet the needs of head injured patients of all types. Through a number of publications on the subject, Headache has offered opportunities to learn about the care of patients we all have always seen, but not quite understood. The now 2-year-old Post-Traumatic Headache Section has brought interested parties and leaders in the field together to discuss how best to study and treat the headaches attributed to mTBI. Eventually, classification will lead to organized trials. And smaller more intense studies of special populations will provide opportunities for translational research creating treatments to relieve the suffering which now eludes our best efforts. The AHS and Headache, through articles such as the one in this current edition, are to be commended for their commitment to these efforts.
At SRCs and ARMCs around America, clinicians screen returning soldiers to find and identify the health concerns of those who have served. Many of those who were killed in the tragedy at Ft. Hood were people working at the SRC, doing the work of processing those who made it back. The paper in this month's Headache was written by a soldier not far from that hallowed ground. The roads that lead into and out of the military towns of America are straighter and wider than the casual traveler might think is necessary. They are built that way to carry heavy loads. The views expressed herein are those of the author and do not reflect the official policy of the Department of the Army, Department of Defense, or the US Government.