Electronic Thesis and Dissertation Repository


Master of Science




Dr. J Kevin Shoemaker


Although cerebrovascular impairments are believed to contribute to concussion symptoms, little information exists regarding brain vasomotor control in adolescent concussion, particularly during changes in arterial blood pressure (ABP). This research tested the hypothesis that adolescent concussion is marked by impaired dynamic cerebral autoregulation (dCA). Thirty concussed adolescents and thirty healthy controls completed two sit-to-stand trials. Cerebral blood flow velocity and ABP were measured continuously. Cerebrovascular resistance (CVR) was calculated and the rate of drop in CVR relative to the change in ABP provided the rate of regulation (RoR). The concussed adolescents were followed through rehabilitation for up to 12-weeks. At the first visit, the concussed adolescents demonstrated reduced RoR compared with the healthy controls (0.16±0.04 vs. 0.21±0.07 sec-1; P≤0.001). At the concussed adolescents final visit, RoR recovers to levels seen in the healthy controls (0.21±0.08 vs. 0.21±0.07 sec-1; P=0.93). Concussed adolescents demonstrate an impairment in dCA that recovers with symptoms.