Computer modelling of CSF flow in the subarachnoid space

Computer modelling has been undertaken to determine the resistance to flow in the subarachnoid space (SAS) and to investigate its contribution to the total pressure drop. A Computational Fluid Dynamics model has been used to determine the pressure drop as a function of both the flow rate and the permeability of the subarachnoid space. The conclusion is that the SAS contributes about 1–5% of the total CSF flow resistance. However, scarring of the arachnoid fibres could increase the flow resistance considerably.