Simulation of cerebrospinal fluid transport

The pulsatile nature of the CSF movement is a result of the cardiac-related pulsations in blood volume in cranial region. According to Monro–Kellie Doctrine, the net inflow of arterial blood during systole is compensated by an equal outflow of venous blood and by caudal displacement of the CSF. Knowledge of the distribution of physical properties (compliance, resistance) along the craniospinal system is crucial for understanding of the CSF hydrodynamics. The synthesis of both invasively and non-invasively obtained data is needed. The aim of our project was to develop a lumped-parameter compartment model of the craniospinal system and, in relation to the cardiac-related blood-volume pulsations, to describe its basic hydrodynamic properties. The model consists of six compartments representing major parts of the craniospinal system. Each compartment has its own set of physical properties which describe its behavior. The pressure transmission from head arteries to the brain compartment serves as a source of pulsations. The simulation tightly mimics pressure waves of the CSF and thus the flow characteristics and magnitudes. The fitted compliance of the spinal compartment in our model was two orders higher (9 × 10−10 m3/Pa) then the cranial compartment (5.2 × 10−12 m3/Pa): only in this adjustment pulsations were present. It makes 99.5% of compliance related to the spinal canal and 0.5% to the intracranial structures. Our fitting showed that this model might be used in medical education as well as in medical practice.