History Of Heading In Soccer Impairs Cognition But Not Cerebral Perfusion In Young Amateur Players

Introduction: Heading the ball in soccer has been linked to impaired cognition and may increase the risk of neurodegenerative disease. This may be explained by an accelerated decline in cerebral perfusion, a major risk factor for cognitive impairment, stroke and dementia, for reasons that remain unclear. 
Purpose: To determine if a history of recurrent heading of a football predisposes to cerebral hypoperfusion and cognitive impairment. 
Methods: Twenty-nine amateur male soccer players (age: 28 + 6 yrs) with a playing history of 15 + 6 yrs and a self-reported heading frequency of 9 + 4 balls per game were recruited for the study. They were compared to 32 age and fitness-matched controls who had not participated in contact sports with no history of concussion. All participants completed a battery of psychometric tests that assessed learning and memory (Rey-Auditory Verbal Learning Test), working memory (Repetition of Digits Backwards; Trail Making Test B) and attention and information processing (Repetition of Digits Forwards; Trail Making Test A; Digit Symbol Substitution Test). A sample of the soccer players (n = 13) and controls (n = 22) also completed a cerebrovascular screening whereby middle cerebral artery velocity (MCAv) and mean arterial blood pressure (MAP) were assessed using transcranial Doppler ultrasound and finger photoplethysmography, respectively. Cerebrovascular conductance/resistance were calculated as MCAv/MAP and MAP/MCAv. 
Results: Soccer players were characterized by impaired learning and memory, and attention and information processing compared to controls (P < 0.05; Table 1). However, no between group differences were observed in MCAv, CVC or CVR between groups (P > 0.05; Table 1). 
Conclusion: Heading the ball in soccer is associated with impaired cognition that appears to be independent of cerebral hypoperfusion.