A quantitative assessment of the degree to which the presentation of hydrocephalus has caused damage to the brain and/or taken over or interfered with the normal functioning of the body as a whole, or specifically of the central nervous system of an organism, for example based on the number of dilated cerebral ventricles and degree to which they are dilated. Hydrocephalus is a congenital or acquired condition marked by dilatation of the cerebral ventricles, usually occurring secondarily to obstruction of the cerebrospinal fluid pathways, and accompanied by an accumulation of cerebrospinal fluid within the skull.