Children at elevated risk for posttraumatic headache months after a concussion
By Susan Klein, MD, PhD. This article was initially published in our Concussion Update newsletter; please consider subscribing.
Some people recover quickly from headache after concussion, but others take much longer. How do we know as soon as possible what will be the case for someone who has had a concussion?
A recent study in Cephalalgia by Marbil and colleagues tracked the progression of headaches over time in children after a new concussion. They found that post-concussion headaches were common and were more severe in those with a history of headache prior to concussion. Post-concussion headaches often worsened in the first 3 months before gradually improving by 6 months, though 34% of respondents who had had a concussion were still using preventative medication for headache at 6 months.
This study provided two notable insights. First, these researchers tracked symptoms systematically over time, showing that headaches get worse for most over the first weeks and then stabilize. Secondly, they showcased a new questionnaire based on the International Classification of Headache Disorders (ICHD-3) to stratify headache as either migraine-type, tension-type, or not otherwise classifiable. This questionnaire will potentially help clarify whether different types of headaches occur after concussion, explaining why some recover more quickly than others. The study authors note that “No distinct phenotype was found to be clearly associated with PTH [posttraumatic headache] after [mild] TBI,”
This research studied children with concussion (mTBI= 139) or orthopedic injury controls (OI =74) identified at their initial ER visit. Data from parents and patients were analyzed if complete for the intake visit and at least one of the follow-up visits (10 days, 3 months, 6 months). As other researchers have also noted, posttraumatic headaches occurred more frequently in females and in older youth with concussion. About half of the 213 participants had a history of pre-existing headaches, and these individuals had more frequent and more severe headaches during the 6-month follow-up period.
A pre-existing history of headache made it more likely that patients and controls would experience more frequent and more persistent headaches over time. Strikingly, orthopedically injured patients with pre-existing headaches had the same frequency of headache at 3 months as those who had concussion. At 6 months, the frequency of headaches in the concussion group, though less than at 3 months, still averaged about 2 each week. Headache severity was greatest for both groups at 10 days, but at 3 and 6 months, severe headaches were more likely to occur in those who had had concussion compared with orthopedic injury controls. Stratification by headache type had too much variability to conclude that a specific phenotype such as migraine or tension-type headache were more likely to result in persistent headache, likely because of the small number of patients with available data at later time points.
It seems optimistic to conclude that posttraumatic headache is an early and largely self-limited effect of concussion. The study authors do not make that statement, and the limitations of the study are discussed in an article in Neurology Advisor. What remains unanswered is what the risk factors are for persistent headache (what neurologists call chronification) and when in the timecourse of recovery it will become clear that you are the person who might still be having headaches long after your concussion. This study is an elegant start toward that goal.