Characterization and Management of Headache after Mild Traumatic Brain Injury

Abstract

In the United States, approximately 1.7 million traumatic brain injuries (TBI) requiring medical attention occur each year. Seventy-five percent of these cases are classified as mild TBI and post traumatic headache (PTH) is the most common physical symptom after injury. PTH is classified as a secondary headache disorder in the International Classification of Headache Disorders (ICHD-3) criteria for headache classification. In recent large, prospective clinical studies after moderate to severe TBI, prevalence can be close to half of the injured population. Cumulative incidence and prevalence have reported to be even higher after mild TBI. A significant risk factor for PTH was found to be a pre-injury history of headache. The most common headache phenotype using ICHD-3 criteria for primary headache disorders was migraine/probable migraine in over 50% of those with headache, followed by tension-type headache. Though the treatment of PTH is largely empiric, one approach to treatment decisions is to use primary headache characterization of the PTH and treat according to recommendations for that headache.Mild traumatic brain injury (mTBI) has become an extremely important global health issue in the past several years. Considerable attention and interest has focused on several populations susceptible to mTBI: soldiers deployed in war zones, professional athletes and youth involved in school sports activity, and civilians engaged in frequent activities of daily living who may be involved in motor vehicle accidents, falls, or assaults among other injuries.In the United States, estimates for 1.7 million civilian TBIs occurring each year are for those requiring medical attention. The outcomes of known cases resulted in 53,000 deaths, and 275,000 hospitalizations for nonfatal TBI (Faul et al., 2010). It is estimated that 43% of Americans live with disability 1 year after hospitalization and 3.2 million live with residual disability (Corrigan et al., 2010).It has been documented that around 75% of TBI is classified as mTBI, and because many of these events do not lead to immediate medical attention, the scope of the problem is likely underestimated. The etiology of mTBI is likely to be different in different age groups. For example, falls are the most common cause of mTBI in children 0 to 4 years old and in adults older than age 75 (Coronado et al., 2011). Civilian deaths have declined in the past decade, likely from industry improvements in protection of occupants with air bags and seat belts in motor vehicles, protective helmet design for use in sports activities and two- or three-wheeled vehicle use, and other public health driven protective measures.The most common etiology of the additional TBI burden in military personnel in recent Middle East conflicts (Operation Iraqi Freedom and Operation Enduring Freedom) is exposure to combat-related explosions (Eskridge et al., 2012) with approximately 80% of mTBI secondary to blast exposure (Hoge et al., 2008). Injury to military personnel reported by the Congressional Research Service show a total of 253,330 TBI cases between January 1, 2000, and August 20, 2012, with 194,561 mild, 42,083 moderate, and 6,476 severe or penetrating with 10,210 not classifiable (Fischer, 2013).