Rotational impacts induced cerebrospinal fluid pressurization*

Traumatic brain injury (TBI) is a major cause of death and disability in the United States. While TBI has been recognized as a real issue, researchers are still trying to fully understand how the brain works. Especially, the critical role of the cerebrospinal fluid in transmitting and mitigating impacts on the head remains unclear. In this study, a lifelike head surrogate, including a soft, artificial brain matter, a transparent, rigid skull, and the CSF in between, has been developed. The surrogate was exposed to rotational impacts in the sagittal, horizontal, or corona planes. The localized deformation of the brain matter was characterized using the Digital Image Correlation approach. The head surrogate was equipped with multiple pressure sensors to measure the dynamic pressure response of the CSF.  The results show a strong correlation of CSF pressurization with the motion/deformation of the brain matter and the resulting changes in the gap thickness of the subarachnoid space. As the first study of its kind, the paper presents the first quantified measurements of the CSF pressurization during the concussion process. This study improves our understanding of the TBI mechanism due to rotational impacts and lays the foundation for further study on this topic.