Decoding the Tissue Characteristics of Perihematomal Edema in Intracerebral Hemorrhage: Poroelastic and Viscoelastic Perspectives.

Intracerebral hemorrhage (ICH) causes severe brain damage, with perihematomal edema (PHE) contributing to poor outcomes. However, the biomechanical properties of PHE tissue remain incompletely characterized. In this study, we examined poroviscoelastic behavior in edematous brain tissue using a rat ICH model, together with associated structural and molecular alterations. Load-relaxation tests were used to characterize viscoelastic and poroelastic responses, while MRI (magnetic resonance imaging) and histological analyses were performed to assess edema progression and tissue integrity. Proteomics was conducted to characterize molecular features associated with PHE tissue. The results showed that PHE tissue exhibited cellular edema, varying power-law exponents, and altered effective diffusion coefficients. Histological analysis revealed disrupted parenchymal cell networks and reduced extracellular space. Proteomics identified changes in the abundance of cell adhesion proteins and extracellular matrix components, including chondroitin sulfate proteoglycans. Together, these findings provide an integrated description of mechanical, structural, and molecular alterations in perihematomal tissue following ICH, offering a biomechanical perspective on tissue changes during PHE progression.