Acute Effects of Concussion in Youth With Pre-existing Migraines.

OBJECTIVE: To examine associations between pre-existing migraines and postconcussion symptoms and cognitive performance acutely (within 72 hours) after a suspected concussion. DESIGN: Nested case-control study. SETTING: High schools in Maine, USA. PARTICIPANTS: From a sample of 39 161 adolescent athletes who underwent baseline preseason testing, 633 were assessed within 3 days of a suspected concussion. Of these, 59 reported a history of treatment for migraines at baseline (9.3%). These athletes were individually matched to 2 athletes who had a suspected concussion but denied preinjury migraines (total N = 177; age: M = 15.8, SD = 1.3). ASSESSMENT OF RISK FACTORS: Self-reported history of treatment for migraines by a physician. MAIN OUTCOME MEASURES: Post-Concussion Symptom Scale total score, ImPACT composite scores, and individual symptom endorsement. RESULTS: Individuals with a pre-existing migraine disorder endorsed greater symptom severity (M = 8.4, SD = 9.9) compared with controls (M = 4.5, SD = 6.5; Cohen's d = 0.47) at preinjury baseline and acutely after suspected injury (migraine: M = 26.0, SD = 25.5; controls: M = 16.7, SD = 15.4; d = 0.44). Acutely after a suspected concussion, greater proportions of athletes with migraine disorders reported mental fogginess (49.2% vs 33.9%) and memory problems (39.0% vs 24.6%; P < 0.05). Baseline ImPACT composite scores were similar between migraine and control groups (d = 0.04-0.13). Adolescents with pre-existing migraine disorders performed worse after a suspected concussion compared with the control participants on verbal memory (F = 4.32, P = 0.041) and visual memory (F = 3.95, P = 0.049). CONCLUSIONS: Individuals with pre-existing migraine disorders may be at higher risk for worse outcomes, including greater overall burden of symptoms and worse cognitive functioning in the memory domain, in the first 72 hours after concussion.