About 20% of soldiers returning from Iraq and Afghanistan who have a history of concussion or blast exposure experience chronic daily headache (CDH), according to a results of study presented at the 14th annual International Headache Congress (IHC) in Philadelphia.1 This study was conducted at the Traumatic Brain Injury Program at Fort Lewis, Washington, and was led by Captain Brett J. Theeler, MD, a neurologist in the department of medicine, William Beaumont Army Medical Center, El Paso, Texas. Results showed that patients with CDH often had headache onset within 1 week of concussion and were exposed to a greater number of blasts within 60 feet. They were also likely to have symptoms of post-traumatic stress disorder.
From June to October 2008, researchers identified 978 soldiers who had received a diagnosis of concussion, head injury, or blast exposure after returning from Iraq or Afghanistan in the previous 3 months. These patients filled out a 13-item questionnaire, and their responses were analyzed along with their medical records.
Patient headache symptoms originated a median of 11 months before the beginning of the study. On average, those with CDH experienced headache 23 days each month; those without CDH had headaches 5.3 days per month. Of 196 patients with CDH, 130 had migraine, 55 had possible migraine, and 11 had non-migraine headache. Of patients with migraine-type headache, 66% had CDH.
Compared with those without CDH, patients with CDH were almost twice as likely to have experienced headache onset within 1 week of concussion or blast exposure (64%) as well as concussions resulting in loss of consciousness (63%). In addition, more than 30% of patients with CHD had post-traumatic stress disorder compared with only 15% of those without CDH. About half of patients with CDH used abortive headache medications at least 15 days each month, while these therapies were used by only 1% of those without CDH.
A recent article by Theeler and Erickson2 reported that about half of all returning soldiers who receive specialized care for headache have a history of mild head trauma that is often associated with blast exposure. Their head trauma was thought to be the cause of new headaches and may have exacerbated preexisting headache conditions. In both studies, Dr Theeler showed that patients who had sustained head trauma often experience migraine-type headaches.
In general, the cause of migraine remains unknown, and the cause of migraine-type symptoms in patients exposed to concussion or blast is not understood, said Theeler. When asked at the most recent IHC to give his opinion on the origin of these migraine-type headaches in his study population, he said, “I feel these are migraines that have their onset after head trauma.”
1. Theeler BJ, Flynn FG, Erickson JC. Chronic daily headache in returning United States army personnel with mild head trauma or blast exposure. Presented at: the International Headache Conference; September 10-13, 2009; Philadelphia. Abstract.
2. Theeler BJ, Erickson JC. Mild head trauma and chronic headaches in returning US soldiers. Headache. 2009;49:529-534.