Variability and uncertainty in the rodent controlled cortical impact model of traumatic brain injury.

BACKGROUND: Controlled cortical impact (CCI) has emerged as one of the most flexible and clinically applicable approaches for the induction of traumatic brain injury (TBI) in rodents and other species. Although this approach has been shown to model cognitive and functional outcomes associated with TBI in humans, recent work has shown that CCI is limited by excessive variability in lesion size despite attempts to control velocity, impact depth, and dwell time. NEW METHOD: Thus, this work used high-speed imaging to evaluate the delivery of cortical impact and permit the identification of specific parameters associated with technical variability in the CCI model. RESULTS: Variability is introduced by vertical oscillations that result in multiple impacts of varying depths, lateral movements after impact, and changes in velocity, particularly at the prescribed impact depth. CONCLUSIONS: Together these data can inform future work to design modifications to commonly used CCI devices that produce TBI with less variability in severity and lesion size.