One-dimensional simulations enable study of cerebrospinal fluid flow in branching perivascular spaces*

The glymphatic system efficiently removes metabolic wastes, such as amyloid$-\beta$, from the brain by utilizing cerebrospinal fluid (CSF) flow through perivascular spaces (PVSs), annular pathways surrounding cortical arteries and veins. Neurodegenerative diseases such as Alzheimer's are connected to reduction in fluid transport and accumulation of amyloid$-\beta$ in the brain. A leading hypothesis suggests arterial pulsations drive CSF flow through PVSs via peristalsis. Some prior numerical simulations refute this idea, but they solely employ small arterial segments with no bifurcations. Our work utilizes 1D modeling to investigate flow in complex branching geometries without excessive computational cost. By employing realistic values for geometry of brain vasculature and arterial pulsations, we quantify peristaltic transport in complex, branching networks and explore how changing peristalsis wave parameters might alter fluid flow in such geometries.