A Lumped Parameter Modelling Study of Leukoaraiosis Suggests its Vascular Pathophysiology is similar to Normal Pressure Hydrocephalus

Introduction: Leukoaraiosis (LA) or white matter disease is a significant component of vascular dementia. There is a large overlap noted between normal pressure hydrocephalus (NPH) and LA. A previously reported lumped parameter modelling study of NPH lead to novel findings in this disease. Given the overlap between LA and NPH, the purpose of the current study is to perform a lumped parameter study into LA to see if the vascular pathophysiology is similar to NPH. Methods: A lumped parameter model originally developed to study normal pressure hydro-cephalus was extended to investigate LA. The model was constrained by the known cerebral blood flow and cerebral blood volumes found in LA, as derived from the literature. Results: Similar to NPH, in LA there was a balanced increase in arterial and venous outflow resistance, with the re-sulting ischemia affecting the white matter rather than the grey matter. However, unlike NPH, in LA the findings are irreversible, most likely due to structural venous wall changes. Conclusions: The model suggests the vascular physiology of LA is very similar to NPH. A common patho-physiology is discussed based on a pulsation induced increase in the venous outflow resistance.