Acute effects and recovery after concussion in high school athletes: A clinical and functional magnetic resonance imaging (fMRI) study.

Principle Investigator: Michael McCrea, Ph.D., ABPP.

Institution: Waukesha Memorial Hospital, Waukesha, WI

Title: Acute effects and recovery after concussion in high school athletes: A clinical and functional magnetic resonance imaging (fMRI) study.

Background & Significance: The current proposal represents a continuation of a large-scale study on the acute effects and recovery following concussion in high school athletes. We have enrolled more than 2,500 high school athletes, studied the recovery pattern in 70 injured players, and utilized functional magnetic resonance imaging (fMRI) to investigate brain activation changes in 20 athletes within 24 hours of concussion. Our preliminary findings have begun to elucidate the clinical and physiological recovery course following concussion.

Objective: The current proposal is intended to build on our research findings by expanding the sample, incorporating an intermediate recovery assessment point not present in our earlier studies, and increase our sensitivity to abnormalities of functional activation by shifting our imaging platform from a 1.5T to a 3.0T MRI scanner.

Specific Aims: The scientific aim of this study is to utilize innovative fMRI techniques and standardized testing (e.g., neuropsychological, postural stability, and symptom assessment) to gain a better understanding of the acute effects and recovery from sports-related concussion, both clinically and neurophysiologically. Our findings are expected to support empirically-based recommendations for tracking recovery, instituting a symptom-free recovery period, and making clinical decisions about an athlete’s return-to-play after sport-related concussion.

Research Design & Methods: Approximately 2,000 male and female athletes participating in football, soccer and hockey at 16 Milwaukee-area high schools will be enrolled during the next two years of the study. All athletes will undergo preseason baseline testing on several concussion assessment measures. All subjects who sustain a concussion based on the American Academy of Neurology (AAN) definition and criteria will be re-tested on these measures immediately after injury and at several post-injury time points. Based on the frequency of concussions during the first 4 years of the study, approximately 60 additional concussions will be studied over the next two years. Injured subjects who exhibit loss of consciousness or post-traumatic amnesia associated with their concussion will undergo fMRI studies using a 3.0T magnet on 1, 8 and 45 days following injury. Matched controls will undergo standardized testing and fMRI studies at these same assessment points. Imaging studies will include a resting scan measure of interhemispheric coherence (cerebral connectivity) and a verbal memory scanning activation paradigm (Sternberg task). Mixed model repeated measures analyses of variance, reliable change indices, and regression modeling techniques will be used to determine if time-dependent group differences exist on clinical measures and fMRI parameters across assessment points. Deconvolution and COSLOF techniques will be used to analyze fMRI data.