The Influence of Sulci Trabeculae in Mitigating Impact Induced TBI

Traumatic brain injury (TBI) is an intracranial injury caused by impacts or angular accelerations of the head such as a violent blow, a bump, a projectile, or even a blast. TBI is a major problem that accounts for over 1.4 million emergency room visits in US. Thus, it is important to understand and predict the occurrence of TBI. Previous studies have shown that the interaction between the subarachnoid space (SAS) trabeculae and the cerebrospinal fluid (CSF) plays an important role in damping the effect of impacts and reducing the brain injuries. However, the influence of sulci parameters and sulci trabeculae in impact induced TBI is still unexplored. A few studies have shown that inclusion of sulci in brain models alters the brain injuries conclusions, even though those models do not take into account the trabecular tissue present in the sulci. In this study, to obtain a perspective of the morphology and architecture of the sulci trabeculae at the frontal lobe of the brain, Human cadaver brain of an 87 year old male was used. For the first experiment, several sulci from the frontal lobe were sectioned and measured to find the average sulci depth, using the image processing software called ‘ImageJ’. This experiment was followed by the Scanning Electron Microscopy (SEM) study on the samples prepared from the frontal lobe. Indeed, numerous images were taken at various magnifications to find different trabecular morphology and architecture in the sulci. The results from the experimental studies were used in our numerical analyses. To do so, the validated global 3D FE model of the human head and neck, created at The City College of New York, were impacted by a rigid barrier on the forehead. The pressure time history, beneath the skull, was calculated during and after the impact. Moreover, a local 3D FE model has been created, having the meninges and the brain with sulci, including the trabeculae and the CSF. The depth of the sulci and the architecture of the trabeculae have been inspired by the imaging and SEM studies. Indeed, the top surface of the local model was subjected to the pressure loading condition obtained from the global model. The results of the finite element simulations reveal that the interaction between the trabeculae and the CSF inside the sulci, would affect and reduce the movement and displacement of gyri and sulci’s walls when the forehead of the head is impacted by an elastic barrier.