ReviewScaling in neurotrauma: How do we apply animal experiments to people?

- Scaling is essential for translating neurotrauma models to the human equivalents.
- We review the principles of biomechanical scaling, with a focus on blast TBI.
- Increasing model brain mass increases tolerance to blast TBI.
- Most blast TBI models do not consider how the biomechanics scale to humans.
- Non-realistic loading conditions can be produced without considering scaling effects.

Scaling is an essential component for translating the clinical outcomes of a neurotrauma model to the human equivalent. This article reviews the principles of biomechanical scaling for traumatic brain injuries, and a number of different approaches to scaling the dose (inputs) and response (outputs) of an animal model to humans are highlighted. A particular focus on blast injury scaling is given as an ongoing area of research, and discussion on the implications of scaling on the current blast TBI literature is provided. The risk of using neurotrauma models without considering an appropriate scaling method is that injuries may be induced with non-realistic loading conditions, and the injury mechanisms produced in the laboratory may not be consistent with those in the clinical setting.