In a study of children who had traumatic brain injury, almost half of them experienced chronic headache months later.
Moreover, adolescents and girls are particularly likely to develop posttraumatic chronic headache, an "intriguing" pattern which parallels that for migraine and lends "support to the theory that the pathophysiology of posttraumatic headaches after TBI [traumatic brain injury] may share similarities with the pathophysiology" of primary headache disorders such as migraine, said Dr. Heidi K. Blume of the division of pediatric neurology at the University of Washington, Seattle, and her associates.
Given that more than 500,000 children and adolescents are assessed for TBI in hospitals every year in the United States, the study findings indicate that many pediatric patients suffer from TBI-associated chronic headaches, they noted in the report published online Dec. 5 in Pediatrics.
Chronic headaches that affect children "interfere with school, social function, [and] parental productivity, and are associated with poor quality of life," the researchers said.
Until now, little has been known about posttraumatic headache in children because most studies in the pediatric population have been small, retrospective, lacking a control population, or of short duration. Dr. Blume and her colleagues addressed these issues by analyzing data from the Child Health After Injury Study, a large, prospective study with 12 months of follow-up that included a control group of children who had sustained arm injuries (Pediatrics 2011 Dec. 5 [doi:10.1542/peds.2011-1742]).
The investigators determined the prevalence of chronic headache at 3 months and 12 months following mild, moderate, or severe TBI in 512 study subjects and 137 controls aged 5-17 years who were treated in the emergency departments at nine hospitals during an 18-month period. The facilities included two children’s, two university, and six community hospitals.
Postconcussive symptoms were common among children, and women are at higher risk of posttraumatic chronic headache than are men.
The researchers used the Centers for Disease Control and Prevention’s definition of TBI (a blunt or penetrating injury to the head that was documented in the medical record and was associated with a decreased level of consciousness, amnesia, an objective neurologic or neuropsychological abnormality, and/or an intracranial lesion).
Most TBIs in this study were sustained either in a fall or when the head struck an object; most of the moderate or severe TBIs were sustained in falls or in motor vehicle or bicycle accidents. Similarly, most arm injuries in the control group were sustained in falls.
At 3 months and 12 months after TBI, the subjects’ head pain during the preceding week was assessed by questioning the parents as well as the subjects themselves if they were aged 14 years or older and able to complete a short survey.
At 3 months, the overall prevalence of headache was 43% among children with mild TBI and 37% among those with moderate or severe TBI, compared with 26% among the control subjects.
At 3 months, chronic headache also was significantly more likely to affect adolescents than younger children, and to affect girls rather than boys. The frequency of headache also was elevated in children of all ages in the TBI group at 3 months, but was significantly elevated only in adolescents.
Similarly, serious headache was more common in children of all ages in the mild TBI group than it was in controls at 3 months, but only significantly so in girls, and it became more prevalent with increasing age. For example, the prevalence of serious headache among girls with mild TBI was 7% at age 5-7 years, 20% at age 8-10 years, 29% at age 11-13 years, and 45% at age 14-18 years, the investigators said. The prevalence of serious headache after moderate/severe TBI was significantly greater only for younger children, at 32%.
The findings were different at 12 months after TBI, with chronic headache reported in 41% of children with mild TBI, 34% of those with moderate or severe TBI, and 34% in the control group, which were nonsignificant differences. Girls were found to have a higher prevalence of headache (52%) than were boys (36%), but this difference did not reach statistical significance.
The subgroup of girls with mild TBI had a higher prevalence of severe headache (27%) than did controls (10%) at 12 months. Adolescent girls also reported more frequent headaches and more severe headaches than did adolescent control subjects, but although these differences were "substantial," they did not reach statistical significance because of small sample sizes in these subgroups.
Overall, the study results accord with those of other recent studies reporting that postconcussive symptoms were common among children and that women are at higher risk of posttraumatic chronic headache than are men.