Neuropathological aspects of dementias resulting from abnormal blood and cerebrospinal fluid dynamics.

The anatomical features of dementia associated with communicating "normal-pressure" hydrocephalus (NPH) are meningopathy at the basis or on the convexity, and fibrosis of the choroid plexus and/or arachnoid villi of post-inflammatory or undetermined origin, and other non-specific changes (periventricular gliosis).