Animal model for sport-related concussion; ICP and cognitive function.

Abstract

BACKGROUND: We have recently developed and characterized a rat model of mild traumatic brain injury which simulates the concussive injuries frequently encountered by players in American professional football. OBJECTIVES: To study the effect of multiple impacts to the head on intracranial pressure, cognitive function, and exploratory behavior. MATERIALS AND METHODS: The model was employed to cause concussion. Intracranial pressure, cognitive function, and exploratory behavior were examined following the multiple impacts of a 50 or 100 g projectile at a velocity of 9.3 or 11.2 m/s to the helmet protected head. RESULTS: Intracranial pressure measured at 6 and 10 h, and 1, 2, 3, 5, and 7 days. It was maximally elevated 10 h after impact and returned to the control levels 7 days later. Morris Water Maze assessment, 48 h after impact, revealed impaired cognitive function. Open field testing 2-4 days and 1 and 2 weeks after impacts indicated consistently reduced spontaneous exploratory activity. CONCLUSION: Multiple impacts to the head raise intracranial pressure and impair cognitive function and exploratory activity in this animal model.