Concussed high school football players who experience symptoms of post-traumatic migraine (PTM), such as headache, nausea, and sensitivity to light or noise, are more cognitively impaired and take longer to recover than those reporting headache without migraine-based symptoms or no headache at all, says a new study. (1)
Previous research had suggested that patients with PTM after concussion report more symptoms and cognitive deficits after injury than patients without PTM (2), but whether the effects persisted beyond the first week of injury or whether PTM within the first few days of injury predicted recovery time was unknown.
Researchers at the University of Pittsburgh and several other institutions theorized that patients with PTM after concussion would report more symptoms and worse cognitive deficits than those reporting only headache or reporting no heaache.
To test their hypothesis, they divided 138 concussed male high school football players from western Pennsylvania and northern California into three groups based on their self-reported symptoms: (1) PTM (headache, nausea, and photosensitivity or phonosensitivity): (2) headache (headache without the other PTM symptoms); and (3) no headache (no headache or PTM symptoms). They further divided the three groups based on the time it took for them for to become symptom-free at rest, back to baseline cognitive performance at rest, and symptom-free after exertion: either prolonged (>21 days) or rapid (<7 days).
What they found was that the presence of PTM after concussion was associated with increased cognitive impairment and recovery time. Those with PTM:
- performed significantly worse than the other two groups on computerized neurocognitive tests of visual memory and reaction time, and lower on tests of verbal memory compared to the headache only group;
- scored signficantly higher on all of 4 of the symptom factors (cognitive, somatic, emotional, sleep) throughout the course of recovery (1-7 and 8-14 days); and
- were 7.3 and 2.6 times more likely to take 21 days or more to recover than the no headache group or headache group, respectively.
Migraine "strong predictor" of concussion severity or recovery
The data showed that headache without associated migraine-type symptoms was not significantly linked with protracted recovery time and that patients without headache actually performed worse on verbal memory than did patients with headache during the early recovery phase (1-7 days after injury). To Anthony P. Kontos, Ph.D. of the University of Pittsburgh Sports Medicine Concussion Program and his colleagues, these results showed that "headaches alone are not a good predictor of concussion severity," especially given that it is the most common reported symptom of recovery, reported by as many as 93.4% of concussed athletes in one recent study. (3)
By contrast, wrote Kontos, the data showed an association between post-traumatic migraine and concussion severity, not only in terms of poorer performance on tests of verbal and visual memory and reaction time and increased symptoms, confirming the findings of a 2005 study (2), but that the impaired cognition and increased symptoms persisted throughout the first two weeks of recovery, and that, in contrast to the broader symptoms of headache, the "more specific symptoms of PTM are a strong predictor of concussion severity."
Kontos and colleagues suggested that one possible explanation for their findings of increased recovery time for concussed athletes with PTM was because they have more severe or frequent headaches than those in the headache group and would be expected to do worse "on all things cognitive because they are in severe and constant discomfort," although it was, they said, also possible that the differences were the result of a "more malignant pathogenesis of PTM."
A pre-injury history of headaches or migraine, however, did not predispose patients to more severe concussion or prolonged recovery time as prior studies had suggested. The study said one possible explanation for this finding was that patients with a history of headaches or migraines may develop a new biochemical baseline or threshold for pain, so they develop posttraumatic headaches and migraines at a rate similar to those athletes with no history of prior headaches and migraines.
More conservative treatment and research recommended
That athletes with PTM were 2.6 times more likely to have a protracted recovery than those athletes with headache without migraine symptoms suggests that they should be treated more conservatively to promote optimal recovery. Future research to explore whether patients with PTM after concussion would benefit more from initial cognitive and physical rest than patients with headache only and those with no headache was recommended.
The finding of a strong relationship between PTM symptoms and cognitive impairment in athletes sustaining concussion lent support, wrote Kontos, to the use of cognitive testing to "identify specific cognitive deficits in patients with and without PTM symptoms after sports concussions. ... Given the pronounced differences in the neurocognitive profile between headache and PTM patients in the current study, future studies should delineate a specific cognitive profile for PTM following concussion" which could be used to "inform subsequent clinical treatment recommendation" with the goal being to "improve clinical outcomes for patients with sports-related concussions."
"The current study is not without limitations," wrote Kontos:
- Only male football players studied. Whether the results apply to females and to athletes in other sports and age groups is unknown.
- Reliance on self-reported symptoms. Previous studies have shown that self-reported symptoms can be unreliable.
- Only personal history of headache and migraine considered. Family history of these conditions - which may predispose athletes to concussion and/or trauma-triggered migraines - was not taken into account, although the study noted, "given the age of the patients, some of them may yet to be diagnosed with migraine or chronic headache conditions. Studies suggest that a history of pre-existing migraine headaches may be an independent risk factor for a concussion and may be associated with a prolonged recovery. (4,5)
- Data on specific type of migraines not gathered. Given the preceding the limitations, further research on the role of both personal and family history and the type of migraines (eg. with aura, without aura, location)(6) is warranted.
- Timing of testing differed. Participants were tested only once during the 1-7 day and 8-14 day period, but some may have been tested 1 day and 8 days after injury, while another may have been tested 7 days and 14 days after injury.
1. Kontos AP, Elbin RJ, Lau B, Simensky S, Freund B, French J, Collins MW. Posttraumatic Migraine as a Predictor of Recovery and Cognitive Impairment After Sport-Related Concussion. Am J Sports Med 2013;20(10). DOI:10.1177/0363546513488751 (published online ahead of print May 22, 2013)
2. Meehan W, d'Hemecourt P, Comstock D. High School Concussions in the 2008-2009 Academic Year: Mechanism, Symptoms, and Management. Am. J. Sports. Med. 2010; 38(12): 2405-2409.
3. Mihalik JP, Stump JE, Collins MW, Lovell MR, Field M, Marron JC. Posttraumatic migraine characteristics in athletes following sport-related concussion. J Neurosurg. 2005;102:850-855.
4. Harmon K, et al. American Medical Society for Sports Medicine position statement: concussion in sport. Br J Sports Med 2013;47:15-26.
5. Gordon KE, Dooley JM, Wood EP. Is migraine a risk factor for the development of a concussion? Br J Sports Med 2006;40:184-185.\
6. Bonfield CM, Lam S, Lin Y, Greene S. The impact of attention deficit hyperactivity disorder on recovery from mild traumatic brain injury. J Neurosurg: Pediatrics 2013. DOI:10.3171/2013/5.PEDS12424 (published online ahead of print, June 25, 2013)
Posted July 4, 2013