Major Finding: Headaches, initially reported by 46% of patients soon after injury, still occurred in 48% at 3 months, 44% at 6 months, and 46% at 12 months.
Data Source: Prospective study of 377 consecutive admissions to acute rehabilitation facilities for traumatic brain injury.
Disclosures: Dr. Lucas said she has no relevant conflicts of interest. The National Institute on Disability and Rehabilitation Research funded the study.
LOS ANGELES — Nearly half of 377 patients with traumatic brain injury reported postinjury headaches that persisted during a year of follow-up in a prospective study.
The prevalence of headaches in the cohort increased from 18% before the injury to 46% soon after injury, according to patient reports during rehabilitation hospitalization for traumatic brain injury (TBI).
In phone interviews after discharge at 3, 6, and 12 months post injury, headaches were reported by 48%, 44% and 46%, respectively.
The persistence of the headaches took senior investigator Dr. Sylvia Lucas and her colleagues by surprise, because previous data have suggested that 18%-22% of posttraumatic headaches are chronic problems.
Dr. Lucas said that she and her associates also were surprised that most of the headaches in the current study were classified as migraine or tension-type headache.
They were also surprised to find that the presence of preinjury headache seemed to be a risk factor for postinjury headache, and that women were at higher risk for postinjury headache.
The findings on types of headache and their persistence could have “important implications for treatment” of posttraumatic headache, said Dr. Lucas, founder and director of the headache center at the University of Washington, Seattle.
Posttraumatic headache is one of the most common persisting symptoms after TBI, occurring in 30%-90% of patients, previous studies suggest. Although most familiar as a salient symptom in soldiers who were exposed to explosive blasts, “it's becoming of great interest in adolescent children who've been in sports concussion injuries,” she said.
The study included consecutive admissions of patients older than 16 years at seven acute rehabilitation facilities for TBI, excluding 79 patients who could not provide consent or answer questions themselves without their families' acting as proxy.
The cause of injury was vehicular trauma in approximately 56%, falls or impacts with flying objects in 28%, violence in 9%, and sports or pedestrian accidents in 4% each. (Percentages were rounded.)
Based on descriptions of symptoms by patients who reported headache, 60% of preinjury headaches were classified as migraine or probable migraine, compared with 48% soon after injury and 54% a year later.
Although 25% of preinjury headaches and 37% of headaches soon after injury were deemed “unclassifiable” by investigators using patients' descriptions, over time they gained features that allowed them to be classified in one of the primary headache classifications, so that the proportion of “unclassified” headache fell to 19% by 12 months post injury.
“Mostly, patients were classified as migraine with or without aura, or tension-type headache, which is also surprising given the fact that most of these were vehicular injuries,” she said.
“There was not a high prevalence of cervicogenic headache,” Dr. Lucas added.
Headaches were classified as tension-type in 12% before injury, in 7% soon after injury, and in 19% at 12 months. Headaches were classified as cervicogenic in 4% before injury, in 8% soon after injury, and in 5% at 12 months.
Among patients who said they suffered headaches before the injury, 48% reported postinjury headache, compared with 23% of patients who said they did not have headaches before the injury.
“Preinjury headache may be a risk factor for posttraumatic headache. This may argue for a common underlying mechanism,” Dr. Lucas said.
The cohort was 71% male and 75% white. Patients were average age 43 years, and 84% of patients were able to be discharged to home.
The injury caused posttraumatic amnesia for less than a day in 7% (indicative of a milder head injury), for 1-7 days in 21%, for 8-28 days in 42%, and for 29 or more days in 30%.
“This was primarily a male group; however, all the way along—at baseline, 3 months, 6 months, and 12 months—there was a statistically significant difference in women having more posttraumatic headache than men,” as well as a higher incidence of preinjury headache, Dr. Lucas said at the meeting.
About 40% of men reported headache at all follow-up time points after injury, compared with approximately 60% of women.
A physician in the audience asked if there was any relationship between insurance claims and reports that the headaches were persisting. “That's a good question, but at the time of our study, that information was not available,” she responded.