Children experiencing headache with migrainous symptoms following concussion are at higher risk for prolonged recovery and persistent headache. This was the main finding of a recently published multicenter, prospective cohort study evaluating post-traumatic headache (PTH) in youths (Kamins J, et al. JAMA Netw Open. 2021;4:e211312, https://bit.ly/3qeApFi).
The study included 281 children ages 5-18 years who were seen at traumatic brain injury specialty clinics within eight weeks of sustaining a concussion. Recovery time and rate of persistent headache were compared across three groups based on symptoms reported at the initial visit: PTH with migraine phenotype (PTH-M), PTH without migraine (PTH-NM) and no PTH.
PTH-M was defined as moderate-to-severe headache that was new or significantly worse compared to baseline and was associated with nausea and/or photophobia and phonophobia. This definition mirrors the International Classification of Headache Disorders 3rd Edition (ICHD-3) criteria for migraine.
Participants in both PTH groups had longer recovery times than those without headache (89 vs. 44 days). The PTH-M group took longer to recover than the PTH-NM group (95 vs. 70 days) and was more likely to report headache at three months.
The rate of PTH was high in this cohort (54%). The sample likely skewed toward more severe and prolonged symptoms because the enrollment period was within eight weeks of concussion at specialty clinics. Some participants without post-traumatic headache may have recovered by the initial visit, though median recovery times for this group still were past the enrollment window.
Though subjects in the PTH-M group had the longest recovery times, participants in the PTH-NM group also experienced prolonged recovery. This suggests that headache may be an important symptom, even in the absence of migrainous symptoms.
The study could not determine whether overall symptom burden also played a role in prolonged recovery, though migrainous symptoms have been found to cluster following concussion.
Overlap between migraine and post-traumatic headache
It has been proposed that migraine and PTH have overlapping symptoms and risk factors because they have shared pathophysiology. Previous studies indicate that children with migrainous symptoms or a personal or family history of migraine are at greater risk for prolonged recovery following concussion.
Kamins and colleagues contribute a more specific diagnosis of migraine phenotype based on ICHD-3 criteria and expand the follow-up period. This study suggests that PTH with migraine phenotype may be a clinical marker of more significant pathophysiology to target for early intervention.
When to refer
The study findings address the conundrum faced by health professionals who treat children with concussion: How to distinguish those at risk for prolonged symptoms from those who will recover rapidly without intervention.
Headache is the most common symptom most children with concussion experience in the first one to two days. While most recover quickly without the need for intervention, about 8% have persistent headache for more than three months (Shaw L, et al. Pain Manag. 2018;8:57-64, https://bit.ly/3qdnWBP).
Prolonged PTH can lead to significant disability and missed school and extracurricular activities. Evidence suggests that there should be a lower threshold to refer children to a concussion or headache specialist early if they are reporting PTH, especially if they have migrainous symptoms, significant disability from headaches and/or a family or personal history of migraine.
Post-traumatic headache treatment
Kamins and colleagues also reported therapies the participating concussion clinics used to treat PTH. Nutraceuticals were recommended for headache prevention in 40% of participants with PTH, regardless of whether migrainous symptoms were present. These included melatonin, magnesium, riboflavin and butterbur. Prescription medications for headache prevention (tricyclic antidepressants being the most common) were used less often and were more likely to be prescribed to the PTH-M group.
These findings draw attention to one of the biggest challenges in improving the outcomes of children following concussion: the lack of evidence-based pharmacotherapies to treat PTH. Indeed, there is a great need for randomized, controlled trials to evaluate treatments for PTH so that data-driven early intervention can be offered to those at high risk.
Dr. Gentile is a member of the AAP Section on Neurology.