Evaluation of brain-skull interface modelling approaches on the prediction of acute subdural hematoma in the elderly

Acute subdural hematoma (ASDH) in the elderly is currently a matter of concern due to the growing number of the aging population and their higher incident rate compared to the younger adults. Computational head models that can replicate this age-related injury pattern are valuable tools to help addressing this concern. Although a biofidelic brain-skull interface modelling strategy is essential for accurate ASDH prediction, approaches with different simplifications have been used in existing head models to simulate the interaction between the brain and skull with their ASDH predictability unknown. Thus, the current communication evaluates the applicability of different brain-skull interface modelling approaches for ASDH prediction associated with age-related brain atrophy. Four representative approaches are selected by simulating cerebrospinal fluid (CSF) as Lagrangian-represented solid and Arbitrary Lagrangian-Eulerian (ALE) represented fluid, each with or without tangential sliding aginst the brain. The chosen approaches are implemented in three models with various degrees of atrophied brain, which are subsequently exposed to an experimentally measured loading known to cause ASDH. The results show, only when simulating the CSF as ALE elements with sliding interface against the brain, a relatively higher ASDH risk characterized by increased cortical relative motion and BV strain peaks are predicted by the atrophied model without causing excessive mesh distortion in the CSF elements. The results of this study provide guidance for brain-skull interface modelling, particularly for the prediction of ASDH in different age groups.