Simulation of brain tissue swelling during stroke treatment / Aina Najwa Binti Nadzri

Faculty of Manufacturing and Mechatronic Engineering Technology

Thesis (Master of Science) -- Universiti Malaysia Pahang – 2025

Includes bibliographical references

Brain edema or brain swelling is defined as the accumulation of water within the brain interstitial as a result of brain injury. In ischaemic stroke, brain edema usually happens due to the disruption of the blood-brain barrier due to a shortage of adequate blood supply to the brain tissue. This will cause the molecules and small proteins in the capillary to enter the brain interstitial, resulting in an increase in water flux into the brain leading to swelling. The swollen tissue can be observed through brain herniation, where the tissue shifted due to the mass-effect of brain stroke infarct and causes the increase of intracranial pressure in the brain. Herniation can be analyzed using advanced imaging such as MRI and CT scan, nevertheless, these are costly and may be harmful to patients. If the swelling is worsened, decompressive craniectomy surgery will be performed, in which a portion of the skull is removed to allow the swelling to expand outside of the skull. The computational model is used to analyze the formation of brain tissue swelling and herniation and also to evaluate the effectiveness of decompressive craniectomy surgery without the need to perform clinical studies. In this project, a mathematical model based on poro-elastic theory and capillary filtration is used to evaluate the effect of infarct sizes and locations on the severity of stroke. Then, a simulation to evaluate the effectiveness of decompressive craniectomy surgery is performed by adding a hole on the surface of the 3D brain geometry. The size of this hole is varied and its effect on brain tissue displacement and pressure is evaluated. The results obtained show that bigger infarcts cause major tissue swelling and compression of the lateral ventricles. Meanwhile, from the craniectomy simulation, performing this surgery does help in reducing intracranial pressure and herniation. However, a small amount of stress present at the contact area between tissue and skull opening may cause other brain tissue injuries. The outcome of this project may be extended further to be useful in clinical practice and surgical decisions related to brain stroke treatment.