The glymphatic system and meningeal lymphatics have recently been characterized. Glymphatic system is a glia-dependent system of perivascular channels, and it plays an important role in the removal of interstitial metabolic waste products. The meningeal lymphatics may be a key drainage route for cerebrospinal fluid into the peripheral blood, may contribute to inflammatory reaction and central nervous system (CNS) immune surveillance. Breakdowns and dysfunction of the glymphatic system and meningeal lymphatics play a crucial role in age-related brain changes, the pathogenesis of neurovascular and neurodegenerative diseases, as well as in brain injuries and tumors. This review discusses the relationship recently characterized meningeal lymphatic vessels with the glymphatic system, which provides perfusion of the CNS with cerebrospinal and interstitial fluids. The review also presents the results of human studies concerning both the presence of meningeal lymphatics and the glymphatic system. A new understanding of how aging, medications, sleep and wake cycles, genetic predisposition, and even body posture affect the brain drainage system has not only changed the idea of brain fluid circulation but has also contributed to an understanding of the pathology and mechanisms of neurodegenerative diseases.

This paper describes the effects of the interaction of cerebral fluids (arterial, capillary and venous blood, cerebrospinal fluid) on ventricular wall displacement and periventricular pressure using a mathematical multiphase poroelasticity model for the cerebral parenchyma. The interaction of cerebral fluids is given by a set of four numerical coefficients. A multiple linear regression with interaction is constructed that allows us to quantify the effect of these coefficients on the average ventricular wall displacement. The prevailing influence of an arterial-liquor component was observed. The sets of coefficients associated with such pathological conditions were found: normal pressure hydrocephalus, intracranial hypertension, and replacement ventriculomegaly under a prolonged hypoperfusion.