The acute effect of heading on neurovascular coupling, optic nerve sheath diameter and memory recall in women footballers

Abstract

Purpose: Retired male footballers are at 3.5 times greater risk of neurodegenerative disease, with repeated heading suggested to contribute to the increased risk. Currently, no such cohort data exist in women players. However, the women’s game is growing, so studies are needed to understand whether heading acutely alters outcomes potentially linked to neurodegenerative disease in this group. Alterations in neurovascular coupling (NVC) may precede the cognitive impairment associated with neurological disease, and evidence suggests that NVC is acutely altered following heading in men. Increased intracranial pressure (ICP) is linked with unfavourable patient outcomes following mild traumatic brain injury. This study assessed whether exposure to a realistic number of football headers acutely influenced NVC, ICP and cognitive function in women footballers. Methods: 19 women footballers completed a heading trial consisting of 6 headers at 40 ± 5 km/h, evenly spaced across an hour, and a time-matched seated control trial. Trials were performed on separate days, spaced a least 7 days apart. The posterior cerebral artery blood velocity response to a visual search task was measured via transcranial Doppler ultrasonography and used to quantify NVC. ICP was evaluated by measuring the optic nerve sheath diameter (ONSD). Finally, cognitive performance was determined using a modified version of the international shopping list test. Each outcome was assessed before and after the heading and control trials. Results: No significant time by trial interaction was present for any metric of NVC (P>0.14, ηp2<0.16), ONSD (P= 0.65, ηp2 = 0.01) or cognitive function (P = 0.053, ηp2 = 0.19). Conclusion: Our data suggests that NVC, ICP and cognitive function is not altered following six headers in women footballers. Future studies should examine how these outcomes are effected by repeated exposure across a season and career.