Simulating Hydrocephalus by a Novel Model of Cerebrospinal Fluid Circulation

Hydrocephalus is an abnormal accumulation of Cerebrospinal Fluid within a cavity called Subarachnoid Space inside the brain as a result of deficits in secretion or absorption procedures. It is believed that Arachnoid Villi cells, which are microscopic projections of Pia-Arachnoid mater that extend into venous channels in Sagittal Sinus providing CSF-vascular interfaces, are the main site for Cerebrospinal Fluid absorption, but it is tempting to speculate that a significant portion of Cerebrospinal Fluid is removed from the Subarachnoid Space by nasal lymphatic vessels around olfactory nerve. In this paper, we proposed a comprehensive model of Cerebrospinal Fluid-Lymphatic-Blood circulation to simulate Hydrocephalus, in which in contrast to other modeling papers, two output pathways for Cerebrospinal Fluid absorption have been considered. The first common pathway pertains to Arachnoid Villi cells and the second novel one to nasal lymphatic vessels. Besides, the bulk flow mechanism that occurs during Cerebrospinal Fluid absorption via Arachnoid Villi cells has been considered in our model. To conform to the physiological conditions that exist in Hydrocephalus disorder, the corresponding elements of circuit have been changed to simulate the effect of each of two pathways. The results showed that for development of Hydrocephalus disorder, the deficit in lymphatic network has more considerable effect in Cerebrospinal Fluid absorption compared with the deficit in Arachnoid Villi cells. It is clarified that Cerebrospinal Fluid is mainly absorbed in lymphatic network and thus, disorders in lymphatic pathway may noticeably result in disorders in Cerebrospinal Fluid i.e. high pressure Hydrocephalus.