cognitive function and dynamic cerebral blood flow regulation in multiple concussions

Background: concussion causes acute, short-term brain dysfunctions. however, the impact of repetitive concussion history on brain function remains unclear. objectives: the present study examined the effect of a history of multiple concussions on the cognitive functions and dynamic cerebral blood flow (cbf) regulation in collegiate rugby football players. methods: nine male rugby football players with a history of ≤ 1 concussion and nine players with a history of multiple concussions (≥ 4 concussions) participated in this study. reaction time and working memory were assessed using a neurocognitive assessment device (cogsport; cogstate ltd., melbourne, australia). arterial blood pressure and middle cerebral artery blood velocity (mcav) were measured continuously throughout the experiment. dynamic cerebral autoregulation was examined using a thigh-cuff occlusion and release technique. results: we found a significant difference in the short-term working memory between players with a history of ≤ 1 concussion and those with a history of multiple concussions (p < 0.05). however, dynamic cerebral autoregulation was not significantly different between the two groups. conclusions: we found a dysfunction in the short-term memory function of collegiate rugby football players with a history of multiple concussions. however, this impairment in brain function was not associated with changes in dynamic cbf regulation.