On the Study of the Role of Arachnoid Trabeculae in Traumatic Brain Injury Under Translational Impact*

Traumatic brain injury (TBI) is a significant health issue resulting from incidents like blasts, falls, and car accidents, often involving translational impacts. The brain is cushioned within the skull by cerebrospinal fluid (CSF). Additionally, the brain's delicate structure is supported by the arachnoid trabeculae (AT), a thin, porous layer connecting the arachnoid mater and pia mater. To investigate the protective role of trabeculae within the brain, we developed an experimental setup that mimics this structure using a thin, porous layer of polyurethane (PU) foam. This foam layer, approximately 3 mm thick, was placed on the surface of a hydrogel brain model within a head surrogate. The head surrogate, filled with cerebrospinal fluid (CSF) and encased in a transparent plastic skull, allowed for detailed observation of brain deformation and pressure dynamics during impact. Two pressure sensors were positioned within the surrogate to measure CSF pressure at the top and bottom regions of the brain. Results indicated that the trabeculae-mimicking PU foam significantly reduced peak pressure at the top region compared to tests without the foam layer, while the bottom pressure remained unchanged. This reduction suggests that trabeculae protect the brain from cavitation effects during impacts. By demonstrating the pressure-mitigating effects of trabeculae, our study provides new insights into brain injury mechanisms and potential strategies for enhancing brain protection in TBI scenarios.