Kids who have a concussion or other traumatic brain injury are more likely to develop headaches for up to a year afterward than children who have had a bodily injury, according to a new study.
While not entirely surprising, the results point to a difficult long-term problem for kids and their parents because adequate treatments are lacking, researchers say.
"It's an issue because they may have problems with sleep, and the headaches can make it harder to concentrate," said lead author Dr. Heidi Blume at Seattle Children's Research Institute.
More than half a million children go to the hospital each year for brain injury.
Blume and her colleagues tracked more than 400 children who had come into the emergency room with a brain injury -- 402 kids had a mild injury and 60 kids had a moderate or severe injury.
Oftentimes the damage was caused by rough play in sports, falls and car accidents.
Blume's team compared these head-injury cases to kids who had come into the emergency room with an arm injury.
Parents and children kept a diary of any headaches the kids reported for a year.
After three months, 43 out of every 100 kids who experienced a mild brain injury complained of headaches.
Among kids with moderate or severe brain injuries, 37 out of every 100 complained of headaches.
In comparison, 26 out of every 100 kids who had an arm injury reported having headaches three months later.
Blume said headaches can have a big impact on kids' lives, affecting their performance in school and forcing them to drop out of sports, band or other activities that could potentially trigger headaches.
It's unclear why the children with mild brain injury were more likely to have headaches than those who suffered more severe damage.
"That is a conundrum that we don't fully understand, but it's been noted before" in research on adults, said Karen Barlow at Alberta Children's Hospital in Calgary, Canada.
"There might be something about the moderate and severe traumatic brain injuries that interfere with the mechanisms of sensing pain," Barlow speculated, "but we haven't gotten to the bottom of that."
The researchers did not determine whether kids who suffered a brain injury were also more likely to have had headaches before the injury than the kids who had an arm injury.
They did find that the risk for having headaches after a head injury was especially pronounced among girls.
Girls who had a mild brain injury were more than twice as likely to have headaches as girls who had an arm injury, whereas boys had nearly similar rates of headaches regardless of the type of injury.
"I'm not surprised about this because it's what I see in clinic," Blume told Reuters Health.
The study, published in the journal Pediatrics, did not determine why there was a difference between the sexes.
Girls might be more likely to report headaches, Blume said, "but I don't think it can all be chalked up to a difference in reporting. I think there's something else going on."
Women and girls are more likely to suffer migraines than men and boys, which could be due to hormone levels, and perhaps hormones might also play a role with headaches after brain injury too.
The greater chance of having headaches among girls could also reflect changes in the way boys' and girls' brains develop, Blume said.
The challenge for any child suffering headaches after a brain injury is that there are few ways to treat them.
"Right now we have no studies to guide the treatment of post-traumatic headaches in children," said Barlow, who was not involved in the new study.
Rest and hydration are usually offered, but Barlow said there's only anecdotal evidence backing them up.
Fortunately, it appears that 12 months after a brain injury, the headaches seem to go back to the levels seen among kids who have had an arm injury.