Current concept of hydrocephalus: evolution of new classifications.

Since hydrocephalus is a multifactorial disease with a diverse pathogenesis, no single, truly ideal classification of its exists. Hydrocephalus has been classified from various standpoints, each classification reflecting the current level of knowledge about hydrocephalus. Hydrocephalus needs to be classified according to the purpose of the study. There are two major categories of classification of hydrocephalus: academic and practical. Untreatable hydrocephalus still occurs. We propose a practical clinical classification based on the time of onset and the etiology for use in the clinico-epidemiologic study of intractable hydrocephalus and its future management.