Chronic daily headache in returning United States army personnel with mild head trauma or blast exposure

Objectives: To determine the characteristics of, and factors associated with, CDH in US soldiers with a history of mild head trauma or blast exposure. Background: Headaches and mild head trauma are common in deployed US Army personnel. Chronic daily headache (CDH) is an especially disabling form of headache. Little is known about chronic daily headache in combat veterans. Methods: Soldiers who screened positive for a concussion, head injury, or blast exposure at the Traumatic Brain Injury Program at Ft. Lewis, WA between June and October 2008 completed a 13-item, self-administered headache questionnaire. All soldiers had returned from Iraq or Afghanistan in the previous 3 months. Analysis of the soldiers with chronic daily headache (CDH), defined as headaches occurring 15 or more days per month for the previous 3 months, was performed and compared to soldiers without CDH. Data were obtained from the headache questionnaire as well as medical record review. Results: 196 of 978 (20%) soldiers had chronic daily headache (CDH). The mean headache frequency was 23 days/month for the CDH group and 5.3 days/month for the non-CDH group. Headaches were migraine type in 66% of soldiers with CDH and 48% of soldiers without CDH. Headaches started a median of 11 months prior in both groups. Headaches began within 1 week of a concussion or blast exposure in 64% of soldiers with CDH compared to 36% of soldiers without CDH. 57% of soldiers with CDH and 60% of soldiers without CDH experienced a concussion while deployed. 63% of concussions in soldiers with CDH resulted in loss of consciousness compared to 33% in soldiers without CDH. The median number of concussions per soldier was 1 for both groups. 62% of soldiers with CDH had been exposed to a blast compared to 76% of soldiers without CDH. Both groups had a median of 3 blast exposures per soldier. 49% of soldiers with CDH used abortive headache medications at least 15 days per month compared to only 1% of soldiers without CDH. The mean PTSD checklist score was 44.8 for soldiers with CDH and 37.2 for soldiers without CDH. 33% of soldiers with CDH screened positive for PTSD compared 15% of soldiers without CDH. The mean military acute concussion evaluation (MACE) score was 25.9 for soldiers with CDH and 27.0 for soldiers without CDH. Conclusions: One in five returning soldiers with a history of concussion or blast exposure has CDH. Factors associated with CDH include migraine-type headache, concussion with loss of conscious ness, headache onset within 1 week of trauma exposure, frequent use of analgesic medications, and symptoms of PTSD.