Head injuries in children's football-results from two prospective cohort studies in four European countries.

Head injuries are considered harmful in children. We analyzed head and neck injuries in organized football in 7- to 12-year-old children. Data for this analysis were obtained from a prospective cohort study over two consecutive football seasons in two European countries, and a randomized intervention trial over one season in four European countries. Football exposure and injuries were documented through an online database. Detailed information regarding injury characteristics and medical follow-up was retrieved from coaches, children and parents by phone. Thirty-nine head injuries and one neck injury (5% of all 791 injuries) were documented during 9933 player-seasons (total football exposure 688 045 hours). The incidence was 0.25 [95%CI 0.15, 0.35] head/neck injuries per 1000 match hours (N=23 match injuries) and 0.03 [95%CI 0.02, 0.03] per 1000 training hours. Eleven concussions (27.5%), nine head contusions (22.5%), eight lacerations or abrasions (20%), two nose fractures (2.5%), and two dental injuries (2.5%) occurred. The remaining eight injuries were nose bleeding or other minor injuries. Thirty injuries (75%) resulted from contact with another player, and ten injuries were due to collision with an object, falling or a hit by the ball. Whereas 70% of all head injuries (N=28) were due to frontal impacts, 73% of concussions (N=8) resulted from an impact to the occiput. The incidence and severity of head injuries in children's football are low. Coaches and parents, however, should be sensitized regarding the potential of concussions, particularly after an impact to the occiput.

Persistent effects of playing football and associated (subconcussive) head trauma on brain structure and function: a systematic review of the literature.

AIM/OBJECTIVE: There is ongoing controversy about persistent neurological deficits in active and former football (soccer) players. We reviewed the literature for associations between football activities (including heading/head injuries) and decline in brain structure/function. DESIGN: Systematic literature review. DATA SOURCES: MEDLINE, Embase, PsycINFO, CINAHL, Cochrane-CRCT, SportDiscus, Cochrane-DSR=4 (accessed 2 August 2016). ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Original studies reporting on football-related persistent effects on brain structure/function. Results from neurocognitive testing, neuroimaging and EEG were compared with controls and/or correlated with heading frequency and/or head injuries. Methodological quality was rated for risk-of-bias, including appropriateness of controls, correction for multiple statistical testing and assessment of heading frequency and head injuries. RESULTS: 30 studies with 1691 players were included. Those 57% (8/14) of case-control studies reporting persistent neurocognitive impairment had higher odds for inappropriate control of type 1 errors (OR=17.35 (95% CI (10.61 to 28.36)) and for inappropriate selection of controls (OR=1.72 (1.22 to 2.43)) than studies observing no impairment. Studies reporting a correlation between heading frequency and neurocognitive deficits (6/17) had lower quality of heading assessment (OR=14.20 (9.01 to 22.39)) than studies reporting no such correlation. In 7 of 13 studies (54%), the number of head injuries correlated with the degree of neurocognitive impairment. Abnormalities on neuroimaging (6/8 studies) were associated with subclinical neurocognitive deficits in 3 of 4 studies. SUMMARY/CONCLUSIONS: Various methodological shortcomings limit the evidence for persistent effects of football play on brain structure/function. Sources of bias include low-quality assessment of heading frequency, inappropriate control for type 1 errors and inappropriate selection of controls. Combining neuroimaging techniques with neurocognitive testing in prospective studies seems most promising to further clarify on the impact of football on the brain.