Pathophysiology of Normal Pressure Hydrocephalus

Abstract

The current perspective for the pathophysiology of normal pressure hydrocephalus is focusing on stiffness of the central nervous tissue, especially on a type of cerebrovascular disorder. Rigid intracranial vessels and tissues derived by either vascular risk factors or aging may lead into impaired dynamics of the cerebrospinal fluid such as increased pulsatility and decreased absorption of the cerebrospinal fluid. Enlarged ventricle may result in a decrease of blood perfusion in brain parenchyma, and in turn global hypoxia and neuro-inflammation along with a breakdown of the blood-brain-barrier. Deterioration of the glymphatic pathway, the crucial disposal pathway of the waste product of the brain, also might contribute to the irreversible injury of the nervous tissue by deposition of abnormal toxic proteins including amyloid beta. Of note, the pathophysiology of the normal pressure hydrocephalus is moving to a type of cerebrovascular disorder instead of the etiology of idiopathic.