Risk of Two Sport-Related Concussions in the Same Year: Is the Second Concussion Worse?

OBJECTIVES: 1) Evaluate the frequency of same-year, repeat concussions; (2) assess predictors of sustaining a repeat concussion; and (3) compare outcomes of athletes with repeat concussions with athletes with single concussion. DESIGN: A retrospective, case-control study. SETTING: Regional sports concussion center. PATIENTS: Adolescents sustaining a sport-related concussions (SRC) from November 2017 to October 2020. INDEPENDENT VARIABLES: Participants were dichotomized into 2 groups: (1) athletes with a single concussion; and (2) athletes with repeat concussions. MAIN OUTCOME MEASURES: Between group and within group analyses were completed to look for differences in demographics, personal and family history, concussion history, and recovery metrics between the 2 groups. RESULTS: Of 834 athletes with an SRC, 56 (6.7%) sustained a repeat concussion and 778 (93.3%) had a single concussion. Between group: Personal history of migraines (19.6% vs 9.5%, χ 2 = 5.795, P = 0.02), family history of migraines (37.5% vs 24.5%, χ 2 = 4.621, P = 0.03), and family history of psychiatric disorders (25% vs 13.1%, χ 2 = 6.224, P = 0.01) were significant predictors of sustaining a repeat concussion. Within group: Among those with a repeat concussion, initial symptom severity was greater (Z = -2.422; P = 0.02) during the repeat concussion and amnesia was more common (χ 2 = 4.775, P = 0.03) after the initial concussion. CONCLUSIONS: In a single-center study of 834 athletes, 6.7% suffered a same-year, repeat concussion. Risk factors included personal/family migraine history and family psychiatric history. For athletes with repeat concussions, initial symptom score was higher after the second concussion, yet amnesia was more common after the initial concussion.