סמינר המחלקה להנדסה ביו רפואית

Intracranial fluid dynamics A mathematical Model

By Yuliya Zadka

Traumatic brain injury (TBI) is the most common cause of death and disability, mainly caused from an accident or falling. A neurological damage can occur from minutes to hours or days after the impact, making it the leading cause of in hospital deaths after TBI. Two major pathophysiological conditions that may evolve after the TBI are Hydrocephalus and Edema. Hydrocephalus defined as an excessive accumulation of CSF mainly in the lateral ventricles. Edema is classified into two main categories: cytotoxic and vasogenic. Cytotoxic edema caused by cerebral ischemia after TBI leads to intracellular accumulation of fluid in the brain tissue cells. Vasogenic edema occurs when there is an increase in blood-brain barrier permeability, which leads to extracellular accumulation of fluid. Those pathophysiological conditions lead to elevated intracranial pressure (ICP) and decreased cerebral blood flow.
In order to understand the complex interactions of brain fluids in healthy and pathophysiological conditions, we developed an intracranial fluid dynamics mathematical model. We used an electrical lumped parameters model technique in order to model the brain fluid dynamics system in an equivalent electrical circuit. The model included three components: blood, cerebrospinal fluid and brain tissue. The rigid cranium enclosing the brain creates a distinctive and complex environment, greatly affecting system dynamics and ICP. Using the model, we were able to reproduce the physiological behavior of the system as well as the pathophysiological behavior at elevated ICP and reduced CBF in Hydrocephalus and Edema.