The Influence of Sport-Related Concussion on Autonomic and Cognitive Function

Annually, as many as 3.8 million sport-related concussions are estimated to occur in the U.S. Emerging research has focused on brain and cognitive impairments due to these injuries; however, the impact of concussions on peripheral physiological measures, such as cardiac autonomic function, warrants attention. PURPOSE: The primary aim was to examine the relationship between cardiac autonomic function in athletes with and without a history of diagnosed concussion and to determine whether autonomic function was related to cognitive function. A secondary aim was to determine if years of high-risk sport participation was related to impairments in autonomic and cognitive function. METHODS: We collected neurophysiological data from sixty-two athletes (20.4 ± 1.7 years) with and without a history of diagnosed concussion. Autonomic function was assessed using low- and high-frequency heart rate variability (LF- and HF-HRV), and pre-ejection period (PEP) at rest and during a paced-breathing challenge. Cognitive function was assessed using behavioral performance (reaction time and response accuracy) and event-related potential (ERP) indices of cognitive control during a modified flanker task. RESULTS: No significant differences in autonomic function were found at rest, p > .05. Paced-breathing increased LF-HRV for all participants, regardless of concussion status, p < .001. Significant differences emerged for PEP, an index of sympathetic cardiac control, suggesting altered autonomic function in individuals with a concussion history. Although there were no significant differences for behavioral performance measures, N2 amplitude was suppressed in athletes with a history of concussion during the flanker task, p < .05. No significant relationships were found by years of high-risk sport participation. CONCLUSION: The findings suggest potential long-term effects of concussion on autonomic and cognitive function. However, these prolonged effects were not associated with years of playing high-risk sports, suggesting that the important factor is the incidence of concussion. Understanding the persistent effects of concussion on integrated neurophysiological measures may aid in the development of more comprehensive concussion prevention and management strategies.